Dedicated AC power...worth it??
mfr
home for Audio?? Is it worth the effort??
Penury
wrote:
>Has anyone had an electrician install a dedicated AC power line in their
> home for Audio?? Is it worth the effort??
Yes, and yes. Of course results depend on how over loaded the line is
and devices added.
Didn't make a huge difference in my case, but noticable. However it
made a great difference in my daughter's case in another home.
-=Bill Eckle=-
ab...@wmeckle.com
Vanity Web pages at:
http://www.wmeckle.com
David Power
wrote:
>Has anyone had an electrician install a dedicated AC power line in their
> home for Audio?? Is it worth the effort??
It made quite a noticeable difference in my set up. I ran two
dedicated twenty amp circuit's to my audio system. One for analog and
one for digital. If I had to do it again I would probably run three
and install quad outlets on them. One for the digital equipment,one
for the amps and one for the analog front end gear. I really think
extension cords and add on distribution panels are expensive and a
fire hazard.
David
Robert Lang
> Has anyone had an electrician install a dedicated AC power line in their
> home for Audio?? Is it worth the effort??
I know this is continually debated, but I believe I have
received considerable benefits from a dedicated
circuit for my system, although the only improvement I can
truly pinpoint with any degree of certainty is a lower noise
floor. I firmly believe there are other benefits but at this
point I call them "intangible".
Keep in mind that I DID NOT install the dedicated line expecting
better audio. I did it because I needed the extra capacity in
the livingroom. My house was built in 1915 and while the
electricity has been upgraded over the years and it is currently
at 200 amps, I suspect much of the wiring dates back many
decades. After installation,I never gave it a second
thought with respect to possible affect it could have on my audio
system. Frankly, I forgot about it and was not expecting nor did I
listen for any
benefits.
But after plugging my system into the the new circuit (the old
circuit is still active) I was very surprised when I sat down to
listen
to my system and immediately noticed that it was almost dead
quiet. I always power on my system on at least 30 minutes prior
to serious listening. I usually walk away before the delay
circuits permit the system to activate. I clearly remember
returning to listen and immediately wondering if I, in fact, had
turned on the system. The quietness was *that* noticeable.
I do believe that other "gremlins", which I had attributed to
pre amp problems, have disappeared or have lessened as a result
of the dedicated curcuit but I have not quantified them nor have
I tried to quantified them. The dramatically lower floor alone
is worth the cost of the new circuit.
Robert C. Lang
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Mike Gilmour
> home for Audio?? Is it worth the effort??
>
installed a dedicated feed to a system with Soundlab A3's, San Pareil OTL
monoblocks. We went slightly OTT and used 26 metres of 25mm (yes 25mm)
armoured cable underfloor via neutral blocks to the incoming tails. The
steel wire armour was grounded as a screen. This led to a consumer unit at
the listening room fitted with RCBO's. The Electricity Board were consulted
thoughout the installation.
The difference between the conventional ring main and this dedicated supply
was nothing short of amazing. A huge improvment in bass control, the whole
sound 'opened up' & a reduction in noise floor. The owner said it felt
like as if the power amplifiers had "doubled in power" and controlled the
Soundlabs with "much greater authority" and said he never know his system
could be a good as this.
It took us two days of work as underfloor was in blocked compartments which
meant a lot of masonery drilling to feed the cable though...was it worth the
effort, a hundred times yes!
Mike
chung
I usually walk away before the delay
> circuits permit the system to activate. I clearly remember
> returning to listen and immediately wondering if I, in fact, had
> turned on the system. The quietness was *that* noticeable.
>
> I do believe that other "gremlins", which I had attributed to
> pre amp problems, have disappeared or have lessened as a result
> of the dedicated curcuit but I have not quantified them nor have
> I tried to quantified them. The dramatically lower floor alone
> is worth the cost of the new circuit.
This is strange. You are saying that your previous AC lines were
responsible for audible noise. Was it 60 cycle hum, or white noise? Was
it preamp, or power amp noise? There must be something significantly
wrong with your equipment to be so sensitive to AC such that new AC
lines give "dramatic" improvements.
Ken Sternberg
recepticle (hospital grade?), would this help in terms of cleaning up
the current?
normanstrong
their
> home for Audio?? Is it worth the effort??
Do you mean a separate distribution transformer out at the pole,
separate drop and separate meter (with its accompanying bill?) The
answer is no.
Norm Strong
Steven Sullivan
Curious parties (such as the founder of this thread) wondering whether
power line conditioning is worth it, and reading this thread's glowing
reports, should of course also consider the usual alternative likely
explanations for the 'amazing' perceived improvements...which I would hope
are familiar enough now that that they hardly need anything more than a
mention. ;>
--
-S.
Mark Wilkinson
> home for Audio?? Is it worth the effort??
>
Well, I hate to rain on the parade of positive comments, but the answer IMO
is most likely no.
But there are conditions when it MIGHT help.
First, you might have wiring that is undersized for the load (amps), and you
get voltage drop. But you'ld also need kinda crappy amps that don't have a
good power supply AND you listen at high volume all the time (where it's
hard to be discerning anyway) , or your running some really high power stuff
(in which case you should be on 220v anyway). Second, your wiring may be
sized right for your audio system, but the extra load of lights, TV etc,
leaves the circuit lacking. Third, your getting noise from dimmers,
computer crap, a wall AC unit, etc, thrown onto your neutral/ground. This
can happen and is often a real benefit of an isolated circuit. But it
doesn't happen as often as you might think. Here's an easy way to see if
you are getting junk on your circuit. Unplug everything besides the audio
on the circuit. You can even flip off all the other breakers in your house
if you want to get carried away. See what you think --- it's that simple.
Oh, and I noticed one person said they are putting in separate circuits for
the amps and the front end. That's one thing I would definitely NOT do.
You want everything on the same ground path. mark
Ron
<mikeru...@earthlink.net> wrote:
I did, with substantial benefits.
In general, running a dedictaed line is only worth it when
there are serious problems that must be corrected. My system
had such serious problems. Whenever the refrigerator in the
kitchen kicked in, my TV dimmed for several seconds. The A/C
in the family room, where the system is located, wreaked
real havoc. When it kicked in, the turntable would stop
playing...
I ran a 20A dedicated line from the circuit breaker box in
the basement to the family room, to power the entire A/V
system. At the same time, I completely re-did the entire
electrical system in the room (using shrouded 12AWG cable),
but left it connected to it's own circuit breaker.
The results were very good. All problems simply disappeard.
Now, when the A/C kicks in, there is a very slight and brief
blinking of the lights in the room (they are connected to
the same line as the A/C). There is no other effect
otherwise.
My system consumes much of the available 20A. TV takes about
2A. The power amplifiers can consume about 7.5A at full
power (total of 5 power amplification channels) and the sub
can consume another 2A at full power. Signal source devices
take about 4A total. In all, I calculated about 15A absolute
maximum draw, with less than half normal draw. A single 20A
line solved all the problems.
-- Ron
bl...@vnet.ibm.com
> home for Audio?? Is it worth the effort??
No (I did it myself). and...
Yes, it was worth it. I think it sounds better, but can't prove it.
If your wiring already has #12 wire and well-made connections, it may not
matter. My house didn't - the old outlets are daisy-chained from
one to the next using spring clips that the wires push into. The
contact they make is bad enough that they sometimes get noticably warm
when something big is plugged into one of the other outlets down the
chain. Less-than-great connections are probably fairly normal.
I used #10 wire and a 15A breaker. #10 is larger than normal but easy
enough to get and work with. Anything larger makes it a rather
difficult job. I have about a 60 foot run from the power
panel, so the lower resistance of the wire may make a difference.
A larger breaker isn't necessary, and may be a safety hazard because
it will allow more current to flow through a piece of faulty equipment
before it will blow.
Bob Blase
Tim Britt & Ann Weatherwax
interest here in dedicated AC lines.
If you are going to add a dedicated AC line for your system, IOHO, there is
*nothing more important* you can do than go ahead and add whole-house surge
protection to your electrical system.
This is nothing more that a giant surge protector your electrician wires
between your fuse/breaker box and the power line entering your home. You
get the added benefit of protecting all your electrical devices and all your
outlets plus your audio system.
We've done this for every home we've lived in for the last 15 years and have
never lost anything to electrical surge when we've lived in places where our
neighbors on both sides of us have suffered really bad electrical surge
damage after severe thunderstorms.
And the prices for this kind of protection seem to be coming down: The
first one we installed around 1987 cost about $200 and was made by the
Square D company. The last one, installed in our home in 1996 cost about
$70 (can't remember manufacturer).
The total cost is very likely less than your insurance deductible, so why
delay? Protect your valuable components.
Tim & Ann
Jeff Wiseman
<<stuff deleted>>
> Oh, and I noticed one person said they are putting in separate circuits for
> the amps and the front end. That's one thing I would definitely NOT do.
> You want everything on the same ground path. mark
I'm not sure that having separate circuits for the front end vs.
back end components will make much difference. The fact that they
both show up in your listening room next to each other allowing
you to distribute your load accross them is probably more signnificant.
The issue that is mentioned about the ground though is
significantly true. A ground loop that includes the amp now has
to return all of the way to the service box. However, a partial
work around for this would be to jumper the grounds together at
the outlets themselves. If you bring both feeds into the same
quad outlet utility box, this is real easy to do (and should be
done). You still would have a potential loop through the hots and
neutrals (which should NOT be tied together) but this is not
nearly as significant a problem as having ground loops passing
through your chassis and coax shields that return to the service entrance.
Also, since you now have redundant ground returns, you've
actually increased the safety factor as well :-)
- Jeff
Norman Worth
voltage sags and surges and from line noise. These come from switching on
and off of large loads and from noisy devices connected to the line. At
home these are likely to be refrigerators, air conditioning, washers, hair
dryers, vacuum cleaners, power tools and such.
Of course, the problem may not come from your house, or you may not have
these problems, in which case isolated power would not do any good. there
are cheaper and more reliable solutions. Look into constant voltage
isolation transformers, which are used in industry to cure such problems.
Also check into uninterruptable power supplies used for computers. Not all
of these provide isolation, but some provide an isolated voltage converter
that operates all the time - that's the kind you want.
"mfr" <mikeru...@earthlink.net> wrote in message
news:5Ksga.222210$eG2.34352@sccrnsc03...
Terry Zagar
I use six 20A dedicated duplex electrical circuits (12 ga standard NM
solid copper 3-wire for each circuit), and each terminated in a duplex
20A hospital grade outlet. These outlets are just standard hospital
grade, not the orange outlets with a separate technical ground that
you sometimes see advocated. Their primary advantage is that they
provide a much tighter contact with the equipment power plugs and
provide a self-cleaning wiping action when inserting or removing plugs.
While one dedicated 20A circuit could easily service all of my
system's power needs, I decided to use multiple outlets and separate
circuits to:
1) Eliminate the need for separate outlet strips (I formerly needed 3)
which make it a pain to change equipment around. Now instead of a
rat's nest of power cables, the duplex power outlets are directly
behind each equipment rack so power lines can be routed straight
across to them at right angles to signal-carrying cables. This also
keeps the power cables off the floor and separated from the
signal-carrying cables.
2) Allow high current (amplifiers), motorized (turntable/CD player),
digital (DAC), and low-level analog (preamp/crossover) components to
use separate dedicated lines. This is per the recommended practices in
Henry Ott's book, "Noise Reduction Techniques in Electronic Systems"
(Chapter 3).
3) Allow those components with 3-wire plugs to be on separate
circuits, avoiding shared common ground currents. Note that in my
set-up, the electrical panel-to-outlet distance is relatively short
(less than 15-20 feet) and the separate circuits are bundled together.
All of the circuits are connected to the same phase side at the
electrical subpanel for hum reduction per Don and Carolyn Davis' book,
'Sound System Engineering', Chapter 15 on Installing the Sound System.
After making this change, noise at high volume settings (with no input
signal) was noticeably reduced (you need to get next to the
loudspeaker to hear it at all). Prior to this, hum was audible at a
much lower volume setting at the listening position. I'd estimate at
least a 6-10 dB reduction in noise level. With the dedicated outlets,
even via the phono stage, with no signal present, there is no
bothersome hum (hiss of course, but hardly noticeable hum), even at
the maximum volume setting to get in the way of the music.
As in all things, YMMV.
Best regards,
Terry
CJT
> Yes to both of your questions.
>
> I use six 20A dedicated duplex electrical circuits (12 ga standard NM
> solid copper 3-wire for each circuit), and each terminated in a duplex
That sounds like an invitation to ground loops to me; how do you avoid
them?
Robert Lang
> Robert Lang wrote:
> I usually walk away before the delay
> > circuits permit the system to activate. I clearly remember
> > returning to listen and immediately wondering if I, in fact, had
> > turned on the system. The quietness was *that* noticeable.
> >
> > I do believe that other "gremlins", which I had attributed to
> > pre amp problems, have disappeared or have lessened as a result
> > of the dedicated curcuit but I have not quantified them nor have
> > I tried to quantified them. The dramatically lower floor alone
> > is worth the cost of the new circuit.
>
> This is strange. You are saying that your previous AC lines were
> responsible for audible noise.
I don't know. But as I mentioned, the house was built in 1915 and
there was original wiring in some places. So I suspect, but I don't
know, that the previous wiring may have contributed to audible noise.
But may be not.
Was it 60 cycle hum, or white noise?
Probably 60 cycle hum, but I don't know. It could have been both.
Whatever noise(s) it was low level and probably intermittent. I had
not identified the noise as a problem because I was not looking for a
problem to resolve.
Was
> it preamp, or power amp noise?
It emanated from the speakers, I don't know the source.
There must be something significantly
> wrong with your equipment to be so sensitive to AC such that new AC
> lines give "dramatic" improvements.
If you say so, fine.
Look. I'm not certain if you are asking your questions to help root
out the problem I experienced or you are questioning what I said I
heard. Or both. Either way is fine. But here are a couple of things to
consider.
1) There was no "expectation bias". The upgrade to the electrical from
50 amps to 200 amps was simply a needed improvement to a 1915 vintage
house. *Safety* was my *only* concern, not the sound quality of my
system. When I first turned on my system after the upgrades were
completed I had forgotten about the new variable (electricity upgrade)
or even that it was a variable. I just sensed (lack of low level noise
I had become acclimated to) something was missing. I even did a double
look to confirm that the system was even on. It was on.
2) "Dramatic" is in the ears, eyes, mind, whatever, of the beholder. I
read a review of some 1950s Acoustic Research speakers where the
reviewer believed that they were so good that it was "just like being
there". Sound familiar? And this was a mono acoustic suspension
speaker no less. When someone uses a word like "dramatic", we as
readers have to keep it in perspective. To me the improvement in the
noise floor was "dramatic". And to *me* this is not hyperbole. To you
the change may have been small or non-existent even if we are hearing
the same thing.
My "claim" (and it does not rise to that level) of lower noise is
downright innocuous compared to any other of the numerous posts in
this thread and past threads that report all kinds of improvements
with a dedicated AC power for their systems. So, if your aim is to
investigate these claims or question their validity you will be very
busy indeed.
Robert C. Lang
chung
> chung <chun...@covad.net> wrote in message news:<FvIga.229317$eG2.37020@sccrnsc03>...
>> Robert Lang wrote:
>> I usually walk away before the delay
>> > circuits permit the system to activate. I clearly remember
>> > returning to listen and immediately wondering if I, in fact, had
>> > turned on the system. The quietness was *that* noticeable.
>> >
>> > I do believe that other "gremlins", which I had attributed to
>> > pre amp problems, have disappeared or have lessened as a result
>> > of the dedicated curcuit but I have not quantified them nor have
>> > I tried to quantified them. The dramatically lower floor alone
>> > is worth the cost of the new circuit.
>>
>> This is strange. You are saying that your previous AC lines were
>> responsible for audible noise.
>
> I don't know. But as I mentioned, the house was built in 1915 and
> there was original wiring in some places. So I suspect, but I don't
> know, that the previous wiring may have contributed to audible noise.
> But may be not.
>
> Was it 60 cycle hum, or white noise?
>
> Probably 60 cycle hum, but I don't know. It could have been both.
> Whatever noise(s) it was low level and probably intermittent. I had
> not identified the noise as a problem because I was not looking for a
> problem to resolve.
>
I thought you had suspected "gremlins" before. I would sort of expect
that you had looked into the nature of those problems, or are at least
familiar with the symptoms.
There could be a simple explanation. You had to reconnect your stereo
because of the new AC outlets. You could have solved a ground loop
problem, or the process of removing and reconnecting the cables could
clean up some corrosion in your connectors.
Your claim of "dramatic lower noise" is very analogous to what the cable
believers say when they switch to a new expensive cable/interconnect,
hence my skepticism.
There is no black magic in what sets the residual noise-floor in a hi-fi
system. If there is a real improvement, then there should be a real
reason. I am just having trouble understanding such a reason(s) in your
case. And it would be satisfying, at least for me, to figure it out.
> Robert C. Lang
>
Ian Smith
news:<DwIga.231260$L1.47275@sccrnsc02>...
>On Thu, 27 Mar 2003 01:46:41 GMT, mfr
>
> >Has anyone had an electrician install a dedicated AC power line in their
> > home for Audio?? Is it worth the effort??
>
All this effort just proves what the real problem is: hi-fi power supplies.
Would you be happy if your PC rebooted every time the a/c came on? Years ago
they solved these problems with proper testing for glitches etc. etc. and
designed the power supplies to cope with it. Many hi-fi manufacturers simply
ignore this problem and tell you to clean your mains up yourself. Isn't that
the purpose of the PSU inside the hi-fi? Don't put up with it.
Demand improvements.
Buy hi-fi that is properly engineered.
Persuade the hi-fi magazines to test the power supplies and name and shame.
Then we can take hi-fi home and have it perform as well as it did in the
shop, raht er than messing around with expensive add-ons.
_________________________________________________________________
Surf together with new Shared Browsing
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Terry Zagar
components, it can occur when two (or more) interconnected components
share the same signal ground through an unanticipated circuit path AND
there is a difference in potential across that unanticipated path of
sufficient magnitude that it reaches an audible level AND the loop
thus formed by the unanticipated path is susceptible to magnetic power
line fields (i.e., 60 Hz signal induction). For small enough
potential drops, even if there is a ground loop, the level of noise
generated is not significant enough to be bothersome relative to the
particular application requirement. It would seem that there are
three possible strategies to overcome ground loops - break the loop
via some kind of isolation transformer, keep potential differences
small enough, or minimize the area of the loop.
The two main ways that I can envision of creating ground loops is when
one has two or more components with 3-wire power plugs, and/or one has
3-wire component interconnections that tie two or more component
chassis together. In my case, 3 out of 6 of my components use 3-wire
power plugs, so I'm a candidate there. All of my interconnects,
however, are via RCA connectors rather than balanced connectors so I
don't have the 3-wire interconnect problem.
So how am I avoiding audible ground loop problems from the separate
ground wires back to the service panel? I suspect it's a combination of:
1. Single-phase power. Power to my home is 240VAC 2-phase. At the
electrical panel, this is broken out into 120VAC circuits, one phase
connected to one-side of the electrical panel and the other phase to
the opposite side (this is a secondary electrical panel with no 240
VAC circuits). In my set-up, I have single-phase power (i.e., all of
my audio power circuits run to the same side of the electrical panel).
This minimizes the opportunity for power phase differences which can
create differences in potential. If my individual outlets were
connected to different sides of the panel, I would expect a greater
likelihood of higher potential differences and, thus, audible hum, due
to the inherent losses in each component's power supply transformer
capacitively coupling power line noise to the component's chassis.
2. Bundling of the power cables from the service panel to the outlet
to minimize the area of any loop.
3. Short power cable runs from the service panel to minimize
resistance, and hence differences in potential.
My test approach for ground loop severity is pretty simple - with no
source playing, raise the volume slowly to maximum and see what comes
out of the loudspeakers. In my prior set-up, the greatest hum occurred
through the phono stage, albeit above my normal listening volume
settings. But the level of hum was such that I never could raise the
volume to maximum without fear of overdriving my loudspeakers. In my
new set-up, with the same equipment and interconnects, I can turn the
volume control to maximum, and I need to put my ear to the
loudspeakers to hear the hum. Obviously, something changed for the better.
May we all be so lucky,
Terry
Robert Lang
I thought you had suspected "gremlins" before. I would sort of expect
> that you had looked into the nature of those problems, or are at least
> familiar with the symptoms.
That's right "gremlins"! Which is why I put it in quotations.
Webster's definition of "gremlin": "an *imaginary* (my emphasis),
mischievous being humorously alleged to cause mechanical failures or
disruption in any activity". In other words, I *confessed* as an
audiophile, upfront, in my initial post, that aside from the lower
noise level, that I clearly achieved, that other improvements may or
may not have occurred and that they may have been imaginary
("gremlins"). I went so far as to say that, aside from the lower
noise, I had not pinpointed nor would I vouch for the occurrance of
any other change in the sound of the system.
> >
>
> There could be a simple explanation. You had to reconnect your stereo
> because of the new AC outlets. You could have solved a ground loop
> problem, or the process of removing and reconnecting the cables could
> clean up some corrosion in your connectors.
Your're musing, which has its place. But for the record, there was one
change and one change only. I plugged my power strip into the newly
installed wiring/receptacle. Besides, if I had done all the "removing
and reconnecting" that you are suggesting we would not be having this
conversation. I would have pointed to *that* as the likely reason for
the lower noise.
>
> Your claim of "dramatic lower noise" is very analogous to what the cable
> believers say when they switch to a new expensive cable/interconnect,
> hence my skepticism.
It may seem analogous but it's not. Check out my system at:
http://cgi.audioasylum.com/systems/1748.html
You will see that there is no place in my system, which itself is
expensive (and well matched), for expensive cable/interconnects. Aside
from good construction I don't believe they offer readily tangible
benefits.
>
> There is no black magic in what sets the residual noise-floor in a hi-fi
> system. If there is a real improvement, then there should be a real
> reason. I am just having trouble understanding such a reason(s) in your
> case. And it would be satisfying, at least for me, to figure it out.
>
OK. But if upgrading from 70-80 year old AC wiring to more modern
wiring is not a possible, if likely, reasonable explanation for the
improvement I don't know what to tell you. I'm not saying that this
explanation for the lower noise I achieved is iron clad, although I do
believe it is pretty defensible. However, based on the myriad of more
profound, wide-sweeping claims already made in this thread, if you
really want to be the gatekeeper on this issue, you have far bigger
fish to fry.
Robert C. Lang
Howard Ferstler
> home for Audio?? Is it worth the effort??
I have two lines going into my main system, with two subs and a
ceiling-mounted video projector on one and everything else (10 more
items, including a big Yamaha RX-Z1 receiver and Carver M500 power
amp) on the second. The circuits also power some lights in that room,
although most of them are handled by a third 20-amp line that also
handles my alarm system, my outdoor sockets, and the motion-dector
controlled lights in my back yard. I think that two circuits like what
I have are essential for that much A/V gear.
Basically, the determining factor will be how much gear you have in
the room. If you have a 100 wpc receiver, a 250 watt sub, a player or
two and a decent-sized TV monitor you can probably get away with a
single line that could also power a few lamps. Check each of your
components and see how much current they draw.
Howard Ferstler
Mark Wilkinson
news:Pu0ha.264818$S_4.169869@rwcrnsc53...
> The two main ways that I can envision of creating ground loops is when
> one has two or more components with 3-wire power plugs, and/or one has
> 3-wire component interconnections that tie two or more component
> chassis together. In my case, 3 out of 6 of my components use 3-wire
> power plugs, so I'm a candidate there. All of my interconnects,
> however, are via RCA connectors rather than balanced connectors so I
> don't have the 3-wire interconnect problem.
>
Hi Terry,
You are probably aware of this ... but just in case ... most components with
RCA connectors tie the sleeve side of the connection to ground. Take a
meter and ohm out any of the RCA connections to either the chassis, the
neutral prong of the AC plug (the larger prong), or the ground plug if so
equipped. So RCA connections provide a ground path just as balanced
connections do.
I think what's really working for you is that you have all your outlets
coming off one phase of your supply. But all in all, I'd have to say
separate circuits really do raise the potential for ground loops, and should
be avoided whenever possible. Not trying to make myself out as an expert,
but I have been a licensed electrician in the past, and my current audio
wiring has dedicated 220 and 110 volt circuits as well as a balanced 110v
supply. I mix allot of balanced and unbalanced gear as well. FWIW, having
done all this my opinion about power is that it's really not worth fooling
with unless you have a known problem -- i.e. low voltage, ground loops, or
noise. My take is that proper gain staging will do a hell of allot more to
make a sytem quieter than fooling with the AC. Later, Mark
chung
I am a little confused. So there was something that made you think that
there were "gremlins" in your system before, no? Or are you now saying
that there was no basis for even imagining that there was something not
right before?
If your previous circuit was not rated to handle the current
requirements, then I would have expected overloads tripping the breaker,
or some other forms of brown-outs. I could think of no reason why that
could cause a lower noise floor, unless your amps have very poorly
regulated supplies. If it were 60 cycle hum, then the problem can be
solved without putting in a new circuit. So in either case, there should
not be a higher noise floor just because the wiring is old.
I don't want to be the gatekeeper on this issue, just like I don't want
to challenge every claim of superior cables. But I thought that you
would have been more interested in figuring out what leads to the lower
noise floor. If you are happy not knowing exactly what resulted in the
improvement, I certainly have no issue with that at all.
Also please understand that I am not suggesting that replacing your
wiring is not the right thing. I upgraded my service from 100 amps to
200 amps, and I am happy, since now I can start a print job on my heavy
duty laser printer without dimming the lights. But I can assure you that
there is no change in the noise floor of my hi-fi system. It is just as
quiet now as before. So as far as I am concerned, there is no audio
benefit in upgrading the ac power, unless you have a capacity issue.
>
> Robert C. Lang
>
Robert Lang
In the future, if someone tells you that there are "gremlins" in their
system (or anywhere else for that matter) there are usually (not
always) attempting to interject a little *humour* in to the
discussion. That is what I was trying to do. Gremlins are imaginary,
they don't exist. What is really being said is that there may be a
"sixth sense", which I don't claim to have, or some sort of undefined
premonition, which I don't claim to have, that something is fouled up.
But that there is *no* basis, solid or otherwise, for expressing their
"feeling". This is particularly true if the reference to "gremlins" is
separated out from the rest of the discussion, which I *clearly* did.
That is any problem referenced with "gremlins" should be rejected out
of hand, which I did years ago on this issue. The humour of that
paragraph was either too subtle or dry that you missed it, which is
understandable. Or perhaps the humour was misapplied. I'll take
responsibility for that. You didn't realize it, but on that particular
part of my post I was on *your* side because that aspect of the
problem was probably imaginary. And I said so *upfront* In any event,
LET IT GO.
>
> >>
> >> There could be a simple explanation. You had to reconnect your stereo
> >> because of the new AC outlets. You could have solved a ground loop
> >> problem, or the process of removing and reconnecting the cables could
> >> clean up some corrosion in your connectors.
> >
> > Your're musing, which has its place. But for the record, there was one
> > change and one change only. I plugged my power strip into the newly
> > installed wiring/receptacle. Besides, if I had done all the "removing
> > and reconnecting" that you are suggesting we would not be having this
> > conversation. I would have pointed to *that* as the likely reason for
> > the lower noise.
> >
> >>
> >> Your claim of "dramatic lower noise" is very analogous to what the cable
> >> believers say when they switch to a new expensive cable/interconnect,
> >> hence my skepticism.
> >
> > It may seem analogous but it's not. Check out my system at:
> >
> > http://cgi.audioasylum.com/systems/1748.html
> >
> > > >>
> >> There is no black magic in what sets the residual noise-floor in a hi-fi
> >> system. If there is a real improvement, then there should be a real
> >> reason. I am just having trouble understanding such a reason(s) in your
> >> case. And it would be satisfying, at least for me, to figure it out.
>
> >>
> >
> If your previous circuit was not rated to handle the current
> requirements, then I would have expected overloads tripping the breaker,
> or some other forms of brown-outs.
Maybe you are on to something. But may be your're not. But I am
certainly not obligated to provide that information to you even if
were true. After all, I'm not seeking any assistance on this issue.
But I am surprised you did not pick up on these possibilities earlier.
See my first post. I made it clear that I made the upgrade for
*safety* reasons. Remember.
I could think of no reason why that
> could cause a lower noise floor, unless your amps have very poorly
> regulated supplies.
You're fishin' here. My amps place a premium in this area. But may be
they do, may be they don't. But if my amps are poorly designed
(they're not) and if a new circuit addresses the issue, then chalk one
up for a new circuit. Although, let's fact it, in most cases a
dedicated circuit is non-invasive and is a fairly cheap upgrade.
If it were 60 cycle hum, then the problem can be
> solved without putting in a new circuit.
Nothing new there. Over the years, I have solved any number of 60
cycle hum problems without putting in a new circuit. I'm sure most
audiophiles who have been in this hobby long enough have had to
address this issue along the way. Are you surmising that I put in the
new circuit to address a 60 cycle hum problem? Remember, that was
*your* diagnosis, not mine. I put the new circuit in for *safety*
reasons, not for any reason related to audio.
I never said there was a 60 cycle hum problem. You surmised that I may
have had a 60 cycle hum problem. You also surmised that I may have had
a white noise problem. You may have been right on one or the other.
You may have been wrong on both accounts. Your were completely wrong
when you surmised that I "removed and reconnected my cables". (Where
did you come up with that?)
So in either case, there should
> not be a higher noise floor just because the wiring is old.
"Either" suggests one or the other. You obviously feel very confident
about your diagnosis. Would you bet the farm that you have correctly
diagnosed the problem that I had? Would you bet the farm that you were
even going in the right direction? I have had highly respected and
experienced electricians to be baffled by the layers of wiring that
have gone into this house for nearly a century. I'm sure that you can
come up with some one sentence rebuttal to show that this is
irrelevant to a noise floor. But the point is that you don't have
enough information to make even a casual diagnosis. (Actually, you do
but you have missed it)
If you are happy not knowing exactly what resulted in the
> improvement, I certainly have no issue with that at all.
>
> Also please understand that I am not suggesting that replacing your
> wiring is not the right thing.
Why would you do that, particularly since it had nothing to do with
audio.? It had to do with capacity and safety!
I upgraded my service from 100 amps to
> 200 amps, and I am happy, since now I can start a print job on my heavy
> duty laser printer without dimming the lights. But I can assure you that
> there is no change in the noise floor of my hi-fi system. It is just as
> quiet now as before.
Of course not, you didn't have a problem to begin with! An even if you
did I never said that changing to a dedicated circuit would solve the
problem. It may be overkill and not even address the problem. OR
depending on the root problem, you may have to do *more* than merely
go to a dedicated circuit.
So as far as I am concerned, there is no audio
> benefit in upgrading the ac power, unless you have a capacity issue.
*Unless*. That is such a pesky word.
if upgrading from 70-80 year old AC wiring to more modern
> > wiring is not a possible, if likely, reasonable explanation for the
> > improvement I don't know what to tell you. I'm not saying that this
> > explanation for the lower noise I achieved is iron clad, although I do
> > believe it is pretty defensible. However, based on the myriad of more
> > profound, wide-sweeping claims already made in this thread, if you
> > really want to be the gatekeeper on this issue, you have far bigger
> > fish to fry.
>
> I don't want to be the gatekeeper on this issue, just like I don't want
> to challenge every claim of superior cables. But I thought that you
> would have been more interested in figuring out what leads to the lower
> noise floor.
I'm interested in a lot of things. I really am. My friends say that
I'm eclectic. But in *this* case I'm not particularly "interested in
figuring out what leads to a lower noise floor". There are several
reason for this. But the most compelling reason in *this* case is
because a little "gremlin" (this time with sarcasm) inside of me says
you are being disingenuous; that you were more trying to prove that I
was imagining what I experienced than trying to get to the root
condition of the problem.
So, of course, I've been coy. Particularly since it was apparent you
did not read my initial post very well. Instead you rushed straight
for what you believed were vulnerabilities. As a result you glossed
over or missed key information. I'm not talking about just the gremlin
thing. For example, look at the third paragraph of my initial post. I
clearly state that my original AC line is still there and still
active. Perhaps, I have plugged my system into it and made
comparisons. You also mentioned that I should not have had a problem
with noise *unless* I had a capacity issue. Go back to my initial
post. I said *exactly* that; I had a capacity issue.
But you also seemed to have a Plan B. If you could not show that I was
imagining improvements as a result of my dedicated circuit, Plan B
would show that I have crappy equipment. You alluded to that several
times. Let me tell you something. You can talk about an audiophiles
Mama, but don't talk about his gear!
Robert C. Lang
> >
Terry Zagar
Mark Wilkinson wrote:
>
> You are probably aware of this ... but just in case ... most components with
> RCA connectors tie the sleeve side of the connection to ground. Take a
> meter and ohm out any of the RCA connections to either the chassis, the
> neutral prong of the AC plug (the larger prong), or the ground plug if so
> equipped. So RCA connections provide a ground path just as balanced
> connections do.
>
I definitely concur with you on this point.
But to create a ground loop, one needs an additional parallel path
interconnecting the different component chassis. That's why I
indicated the issue with 3-wire power plugs in my system - the
combination of the signal ground connection you refer to and my three
3rd wire chassis ground connections 'could' give rise to a ground loop.
In a component with a 2-wire power cord, the hot and neutral power
connections typically go directly to the power transformer and not to
the chassis (for very good safety reasons). The isolation provided by
that power transformer can 'break', or at least minimize through high
impedance, one of the loops I think you are referring to depending on
transformer quality.
> I think what's really working for you is that you have all your outlets
> coming off one phase of your supply. But all in all, I'd have to say
> separate circuits really do raise the potential for ground loops, and should
> be avoided whenever possible. Not trying to make myself out as an expert,
> but I have been a licensed electrician in the past, and my current audio
> wiring has dedicated 220 and 110 volt circuits as well as a balanced 110v
> supply. I mix allot of balanced and unbalanced gear as well. FWIW, having
> done all this my opinion about power is that it's really not worth fooling
> with unless you have a known problem -- i.e. low voltage, ground loops, or
> noise. My take is that proper gain staging will do a hell of allot more to
> make a sytem quieter than fooling with the AC. Later, Mark
Again, with one exception, one addition, and one extension, I concur:
1. The exception - I had a 4th reason to touch my existing power
distribution independent of the three good reasons (low voltage,
ground loops, noise) you mention: to gain more wall outlets and
eliminate power strips (3). I never set out to make things quieter -
that was an unexpected benefit (that I'm quite happy to have :)
2. The addition - because the power cable runs from each of my
outlets are of comparable lengths, I've increased the likelihood that
the three component's with 3-wire power plugs will all have their
chassis at the same potential. Unequal power cable run lengths, as
well as longer run lengths, would increase the opportunity for audible
ground loop problems. But I agree that it is easier to avoid ground
loop problems in the first place by sticking with a single dedicated
power circuit.
3. The extension - I go a step further than you have and avoid
balanced and multi-phase power circuits because I believe they can
contribute to ground loop problems (and added costs) when one
mixes-and-matches components from different manufacturers (i.e., a
greater risk of interoperability problems). I further believe that
I've been able to get the noise reduction benefits of multiple power
circuits (i.e., no common ground impedances in the power lines)
without ground loop problems because I've chosen simplicity (and
careful layout) over complexity in my set-up.
But as you say - I also don't recommend that folks go off and do what
I've done unless they know what they are doing from a 'system' perspective.
Best regards,
Terry
chung
Robert Lang wrote:
>>>>>
snip
>>>>
>>>
>
>
> In the future, if someone tells you that there are "gremlins" in their
> system (or anywhere else for that matter) there are usually (not
> always) attempting to interject a little *humour* in to the
> discussion. That is what I was trying to do. Gremlins are imaginary,
> they don't exist. What is really being said is that there may be a
> "sixth sense", which I don't claim to have, or some sort of undefined
> premonition, which I don't claim to have, that something is fouled up.
> But that there is *no* basis, solid or otherwise, for expressing their
> "feeling". This is particularly true if the reference to "gremlins" is
> separated out from the rest of the discussion, which I *clearly* did.
> That is any problem referenced with "gremlins" should be rejected out
> of hand, which I did years ago on this issue. The humour of that
> paragraph was either too subtle or dry that you missed it, which is
> understandable. Or perhaps the humour was misapplied. I'll take
> responsibility for that. You didn't realize it, but on that particular
> part of my post I was on *your* side because that aspect of the
> problem was probably imaginary. And I said so *upfront* In any event,
> LET IT GO.
>
OK, so you are not sure if there was anything wrong with your system
before. You were making an attempt at humor which I clearly missed. I
wonder if I were the only one.
>>>>
snip
>>
>>If your previous circuit was not rated to handle the current
>>requirements, then I would have expected overloads tripping the breaker,
>>or some other forms of brown-outs.
>
>
> Maybe you are on to something. But may be your're not. But I am
> certainly not obligated to provide that information to you even if
> were true. After all, I'm not seeking any assistance on this issue.
> But I am surprised you did not pick up on these possibilities earlier.
> See my first post. I made it clear that I made the upgrade for
> *safety* reasons.
I never said you made the upgrade for reasons of fixing the sound, did
I? Of course you are not obligated to provide any additional info.
>
> I could think of no reason why that
>
>>could cause a lower noise floor, unless your amps have very poorly
>>regulated supplies.
>
>
> You're fishin' here. My amps place a premium in this area. But may be
> they do, may be they don't. But if my amps are poorly designed
> (they're not) and if a new circuit addresses the issue, then chalk one
> up for a new circuit. Although, let's fact it, in most cases a
> dedicated circuit is non-invasive and is a fairly cheap upgrade.
Not being able to listen to your system or make measurements on it, and
not having sufficient input from you, I am afraid we are perhaps
fishing, for lack of a better word. And I certainly welcome other
explanations. I would also think that if an amp is not designed with
good regulation, then it is not well designed at all.
>
> If it were 60 cycle hum, then the problem can be
>
>>solved without putting in a new circuit.
>
>
> Nothing new there. Over the years, I have solved any number of 60
> cycle hum problems without putting in a new circuit. I'm sure most
> audiophiles who have been in this hobby long enough have had to
> address this issue along the way. Are you surmising that I put in the
> new circuit to address a 60 cycle hum problem? Remember, that was
> *your* diagnosis, not mine. I put the new circuit in for *safety*
> reasons, not for any reason related to audio.
Now when did I say you put in the circuit to fix a 60 cycle hum problem?
Remember I asked you what kind of noise did you hear from your system
prior to your upgrade. Now are you also saying that there were really no
audible noise before the upgrade?
>
> I never said there was a 60 cycle hum problem. You surmised that I may
> have had a 60 cycle hum problem.
Where did I surmise that? I expressly asked you what kind of noise it was.
>You also surmised that I may have had
> a white noise problem. You may have been right on one or the other.
> You may have been wrong on both accounts.
You were the one who said there was a higher noise floor before. Why are
you so defensive when I simply wanted to find out what kind of noise it
was? I was trying to understand how a newer set of wiring can improve
the noise floor. Maybe we can all learn something useful.
> Your were completely wrong
> when you surmised that I "removed and reconnected my cables". (Where
> did you come up with that?)
I offered that as a simple explanation to your problem. If that was not
the case, scratch that explanation. I never said that there was
definitely the case.
>
> So in either case, there should
>
>>not be a higher noise floor just because the wiring is old.
>
>
> "Either" suggests one or the other. You obviously feel very confident
> about your diagnosis.
Well, I was saying that the older wiring should not cause more 60 cycle
hum or more white noise if your amps were regulating properly. I would
love to hear other hypotheses.
>Would you bet the farm that you have correctly
> diagnosed the problem that I had? Would you bet the farm that you were
> even going in the right direction?
No, why would I? I was just trying to analyse the problem (higher noise
floor due to old wiring) based on the limited inputs you provided. Which
by the way may not look like a problem at all.
>I have had highly respected and
> experienced electricians to be baffled by the layers of wiring that
> have gone into this house for nearly a century. I'm sure that you can
> come up with some one sentence rebuttal to show that this is
> irrelevant to a noise floor. But the point is that you don't have
> enough information to make even a casual diagnosis. (Actually, you do
> but you have missed it)
Sure, since all I have is what you have told us, which is very little.
And I was trying to get more info. Which, of course, you are not
obligated to give.
>
> If you are happy not knowing exactly what resulted in the
>
>>improvement, I certainly have no issue with that at all.
>>
>>Also please understand that I am not suggesting that replacing your
>>wiring is not the right thing.
>
>
> Why would you do that, particularly since it had nothing to do with
> audio.? It had to do with capacity and safety!
>
> I upgraded my service from 100 amps to
>
>>200 amps, and I am happy, since now I can start a print job on my heavy
>>duty laser printer without dimming the lights. But I can assure you that
>>there is no change in the noise floor of my hi-fi system. It is just as
>>quiet now as before.
>
>
> Of course not, you didn't have a problem to begin with! An even if you
> did I never said that changing to a dedicated circuit would solve the
> problem. It may be overkill and not even address the problem. OR
> depending on the root problem, you may have to do *more* than merely
> go to a dedicated circuit.
I thought you were sharing your experience with us that going to new
service cleans up your system noise. It seems like you were making a
recommendation. Or was I reading you wrong, again?
>
> So as far as I am concerned, there is no audio
>
>>benefit in upgrading the ac power, unless you have a capacity issue.
>
>
> *Unless*. That is such a pesky word.
Why?
>
> if upgrading from 70-80 year old AC wiring to more modern
>
>>>wiring is not a possible, if likely, reasonable explanation for the
>>>improvement I don't know what to tell you. I'm not saying that this
>>>explanation for the lower noise I achieved is iron clad, although I do
>>>believe it is pretty defensible. However, based on the myriad of more
>>>profound, wide-sweeping claims already made in this thread, if you
>>>really want to be the gatekeeper on this issue, you have far bigger
>>>fish to fry.
>>
>
>>I don't want to be the gatekeeper on this issue, just like I don't want
>>to challenge every claim of superior cables. But I thought that you
>>would have been more interested in figuring out what leads to the lower
>>noise floor.
>
>
> I'm interested in a lot of things. I really am. My friends say that
> I'm eclectic. But in *this* case I'm not particularly "interested in
> figuring out what leads to a lower noise floor". There are several
> reason for this. But the most compelling reason in *this* case is
> because a little "gremlin" (this time with sarcasm) inside of me says
> you are being disingenuous; that you were more trying to prove that I
> was imagining what I experienced than trying to get to the root
> condition of the problem.
>
Well, actually I was taking what you said at face value, and trying to
figure a reason for what you were experiencing. We cannot tell if you
were imagining things unless we know more about your particular
experiences, and eliminate some other possibilities.
> So, of course, I've been coy. Particularly since it was apparent you
> did not read my initial post very well. Instead you rushed straight
> for what you believed were vulnerabilities.
No, I mentioned several possibilities. I fully expected you to either
accept those or reject those. In either case, we could then move on.
> As a result you glossed
> over or missed key information. I'm not talking about just the gremlin
> thing. For example, look at the third paragraph of my initial post. I
> clearly state that my original AC line is still there and still
> active. Perhaps, I have plugged my system into it and made
> comparisons.
OK, so when you plug the system back into the old outlets, do you
experience a higher noise floor? Is it 60-cycle or white noise? Why then
did you say that you could not tell for sure?
>You also mentioned that I should not have had a problem
> with noise *unless* I had a capacity issue. Go back to my initial
> post. I said *exactly* that; I had a capacity issue.
How did that capacity issue show up as more audible noise? I can see
circuit breakers being tripped, or some brown-outs, but not something as
subtle as an elevated noise floor. Unless your amps are not regulating,
which you seem to reject as a possibility.
>
> But you also seemed to have a Plan B. If you could not show that I was
> imagining improvements as a result of my dedicated circuit, Plan B
> would show that I have crappy equipment.
No, I cannot show that you are imagining things. All I said was that
there may be some other reasons, other than new wiring, that account for
your experience. And now that you mention it, imagination is one of
those reasons.
>You alluded to that several
> times. Let me tell you something. You can talk about an audiophiles
> Mama, but don't talk about his gear!
Actually talking about our gear is a large part of what we do in this
newsgroup, if you have not noticed.
>
> Robert C. Lang
>
> > >
>
C. Leeds
> ...So as far as I am concerned, there is no audio
> benefit in upgrading the ac power, unless you have a capacity issue.
There are many potential benefits of installing upgraded and dedicated
AC lines, and this has been shown in practice. Often the greatest
improvement is in improving the quality of ground connections. That can
most certainly reduce noise in a system, especially a complex one with
multiple amplifiers.
C. Leeds
> > I use six 20A dedicated duplex electrical circuits (12 ga standard NM
> > solid copper 3-wire for each circuit), and each terminated in a duplex
> > 20A hospital grade outlet. <snip>
CJT asks:
> That sounds like an invitation to ground loops to me; how do you avoid
> them?
I have multiple dedicated AC circuits also. But because all of the
grounds are of the same length of overspec'd wire (8 ga. and 10 ga. for
20A circuits), ground loops aren't a problem at all. Before I installed
the circuits, I had all sorts of grounding problems using my house's
existing modern house wiring.
Robert Hart
chung
Seems like this is a solution looking for a problem. There are many ways
of tackling ground loop problems without installing new ac service for
the audio system. There are also many ways of introducing ground loop
problems even when there is dedicated or separate ac service for the
hi-fi system.
When you say noise, are you talking about ac line related noise, or
broadband noise?
I have no hum or broadband noise in my system that I can hear without
turning gain all the way up and listening with ears next to the
speakers. So it is an existence proof that you do not need dedicated and
separate ac circuit just for your hi-fi. I am sure many others have the
same experience.
C. Leeds
problems):
> Seems like this is a solution looking for a problem.
Oh no, I definitely had problems before installing the dedicated lines.
Those lines eliminated the problems.
> There are many ways
> of tackling ground loop problems without installing new ac service for
> the audio system.
I tried 'em. In my system, they didn't work.
>There are also many ways of introducing ground loop
> problems even when there is dedicated or separate ac service for the
> hi-fi system.
Quite so. The system has to be properly designed and built to avoid
creating more problems. It's not a guaranteed solution.
> I have no hum or broadband noise in my system that I can hear without
> turning gain all the way up and listening with ears next to the
> speakers. So it is an existence proof that you do not need dedicated and
> separate ac circuit just for your hi-fi.
It proves only that your system doesn't require dedicated lines. But
there are plenty of variables about the quality of AC service and the
quality of existing AC lines within a building. Those factors can make a
difference. The literature on this is abundant.
Howard Ferstler
> C. Leeds wrote:
> > There are many potential benefits of installing upgraded and dedicated
> > AC lines, and this has been shown in practice. Often the greatest
> > improvement is in improving the quality of ground connections. That can
> > most certainly reduce noise in a system, especially a complex one with
> > multiple amplifiers.
> Seems like this is a solution looking for a problem. There are many ways
> of tackling ground loop problems without installing new ac service for
> the audio system. There are also many ways of introducing ground loop
> problems even when there is dedicated or separate ac service for the
> hi-fi system.
>
> When you say noise, are you talking about ac line related noise, or
> broadband noise?
>
> I have no hum or broadband noise in my system that I can hear without
> turning gain all the way up and listening with ears next to the
> speakers. So it is an existence proof that you do not need dedicated and
> separate ac circuit just for your hi-fi. I am sure many others have the
> same experience.
I'm with you. I have three separate systems in my house,
with lots of amplification in each of them. One is supplied
by two 20-amp lines (that also power a couple of lamps), one
is supplied by two 15-amp lines (that also power a couple of
lamps), and one is supplied by two additional 15-amp line
(that also power a few lamps), and none of them have ever
had a problem with power-line noise problems. I have also
set up test systems at different parts of the house in the
past and none of them have ever had problems, either.
I think that most of the time noise problems like that are
the result of the system owner having hardware that was
improperly designed. No standard three-wire electrical feed
should cause noise problems with intelligently designed
audio gear, unless maybe the line is being shared by
something like fluorescent lights, a refrigerator, or other
big-motor device.
Howard Ferstler
Charlie G
news:xsoha.279155$6b3.9...@rwcrnsc51.ops.asp.att.net...
> chung wrote:
>
> I think that most of the time noise problems like that are
> the result of the system owner having hardware that was
> improperly designed. No standard three-wire electrical feed
> should cause noise problems with intelligently designed
> audio gear, unless maybe the line is being shared by
> something like fluorescent lights, a refrigerator, or other
> big-motor device.
>
system into a dedicated AC line, the power transformer--not the driver--on
my powered subwoofer hummed loudly enough to be heard all the way across the
room. The culprit was a table lamp with a compact fluorescent bulb.
The fact that my dedicated AC is also balanced AC may be helping too. When I
plug that same offending lamp into that circuit, it cannot make the
subwoofer's transformer hum like it did when they shared a single-ended
line.
--
Charlie G
Hey SpamBots! Harvest THIS! .
Unsolicited Commercial Email (uce) should be sent to: u...@ftc.gov
Robert Lang
> Wow, seems like I hit a nerve!
I thought I made that clear. Your motives are suspect to say the
least. From the beginning you had zero intentions of being "helpful"
even though you claim that was your original intent. You have this a
mission to contradict or to somehow prove that I had no noise problem
at all let alone a noise problem that was resolved by an electrical
upgrade. We both know it. But that is perfectly OK. It is my choice to
engage in this exchange with you. Were're clearly both enjoying it.
Hey, I'm taking time to respond to your post and have postponed for a
bit to listent to Mahler's 6th. We at least we know where each of us
is coming from. By the way, I do provide you some more clues, most
which you should have been able to figure out on your own if you were
more attentive to my initial post. Enjoy.
>
> Robert Lang wrote:
> >>>>>
>
> snip
>
> >>>>
> >>>
> >
> >
> > In the future, if someone tells you that there are "gremlins" in their
> > system (or anywhere else for that matter) there are usually (not
> > always) attempting to interject a little *humour* in to the
> > discussion. > >
>
> OK, so you are not sure if there was anything wrong with your system
> before. You were making an attempt at humor which I clearly missed. I
> wonder if I were the only one.
I will give you credit here. I truly believe that you, in general,
already understand the noise problem that I have posted. Nevertheless,
to simplify for you the noise problem that I spoke to you must read
the initial post again. Read *only* the first three paragraphs that
clearly speak to the noise problem I had and which was the subject of
the post. The fourth paragraph is the infamous "gremlin" paragraph.
Don't read that paragraph because its causing you fits (although I
really believe that you are just having fun with this, which is OK)
but more importantly because it does not relate in *anyway* to the
noise problem spoken to in the earlier paragraphs. I would say again
about the "gremlin paragraph" to "Let It Go". But clearly you don't
want to. Your choice.
For your convenience the first three paragraphs of the inital post:
"I know this is continually debated, but I believe I have
received considerable benefits from a dedicated
circuit for my system, although the only improvement I can
truly pinpoint with any degree of certainty is a lower noise
floor. I firmly believe there are other benefits but at this
point I call them "intangible".
Keep in mind that I DID NOT install the dedicated line expecting
better audio. I did it because I needed the extra capacity in
the livingroom. My house was built in 1915 and while the
electricity has been upgraded over the years and it is currently
at 200 amps, I suspect much of the wiring dates back many
decades. After installation,I never gave it a second
thought with respect to possible affect it could have on my audio
system. Frankly, I forgot about it and was not expecting nor did I
listen for any
benefits.
But after plugging my system into the the new circuit (the old
circuit is still active) I was very surprised when I sat down to
listen
to my system and immediately noticed that it was almost dead
quiet. I always power on my system on at least 30 minutes prior
to serious listening. I usually walk away before the delay
circuits permit the system to activate. I clearly remember
returning to listen and immediately wondering if I, in fact, had
turned on the system. The quietness was *that* noticeable."
>
> >>>>
>
> >
> >>could cause a lower noise floor, unless your amps have very poorly
> >>regulated supplies.
> >
> >
> > You're fishin' here. My amps place a premium in this area. But may be
> > they do, may be they don't. But if my amps are poorly designed
> > (they're not) and if a new circuit addresses the issue, then chalk one
> > up for a new circuit. Although, let's fact it, in most cases a
> > dedicated circuit is non-invasive and is a fairly cheap upgrade.
>
> Not being able to listen to your system or make measurements on it, and
> not having sufficient input from you, I am afraid we are perhaps
> fishing, for lack of a better word. And I certainly welcome other
> explanations. I would also think that if an amp is not designed with
> good regulation, then it is not well designed at all.
Agreed except for one thing. *You* are fishing. Not "we". I'm not
seeking any information relating to the noise problem that I had. Any
questions that I ask at this point are specific to points that you are
attempting to make.
>
> >
> > If it were 60 cycle hum, then the problem can be
> >
> >>solved without putting in a new circuit.
> >
> >
> > Nothing new there. Over the years, I have solved any number of 60
> > cycle hum problems without putting in a new circuit. I'm sure most
> > audiophiles who have been in this hobby long enough have had to
> > address this issue along the way. Are you surmising that I put in the
> > new circuit to address a 60 cycle hum problem? Remember, that was
> > *your* diagnosis, not mine. I put the new circuit in for *safety*
> > reasons, not for any reason related to audio.
>
> Now when did I say you put in the circuit to fix a 60 cycle hum problem?
I did not say you did. I asked a *question*. I will ask it again. Are
you surmising that I put in the new circuit to address a 60 cycle hum
problem? Yes or no. You certainly suggest it.
> Remember I asked you what kind of noise did you hear from your system
> prior to your upgrade. Now are you also saying that there were really no
> audible noise before the upgrade?
Where did you get that from!? Are you serious? I have said, I bet, 10
times I had an audible noise problem. However, I also said (I'm sure
you will have fun with this) that I did not realize that problem was
as intrusive as it really was until I put in the electrical upgrade. I
had become *acclimated* (look it up) to the noise. Sure, I knew there
was noise *somewhere* in the system. But it was low level and I did
not consider it to be intrusive. I got used to it. Let me give you an
example. I have lived in an urban environment all my life, an
environment which is extremely noisy. I went on holiday to visit my
grandparents who lived in the country side. I immediately noticed the
absence of noise. It was *dramatically* more quiet. When I got the
electrical upgrade I discovered how truly noisy my old line had been.
It was purely serendipitous (look it up). The new line was so much
more quiet (less noisy). I remind you again, there was no "expectation
bias", because I was not expecting *any* improvement in my audio
system.
>
> >
> > I never said there was a 60 cycle hum problem. You surmised that I may
> > have had a 60 cycle hum problem.
>
> Where did I surmise that? I expressly asked you what kind of noise it was.
In your first post you asked and I quote: Was it 60 cycle hum, or
white noise? Again, I say you surmised that I *may* have had a 60
cycle problem.
>
> >You also surmised that I may have had
> > a white noise problem. You may have been right on one or the other.
> > You may have been wrong on both accounts.
>
> You were the one who said there was a higher noise floor before.
OK. So educate me here. There are only two kinds of noises possible in
this situation, 60 cycle hum and white noise? If so, I stand
corrected.
Why are
> you so defensive when I simply wanted to find out what kind of noise it
> was? I was trying to understand how a newer set of wiring can improve
> the noise floor. Maybe we can all learn something useful.
I told you before that I did not know what kind of noise it was. I
made that clear. But then you asked again.
>
> > Your were completely wrong
> > when you surmised that I "removed and reconnected my cables". (Where
> > did you come up with that?)
>
> I offered that as a simple explanation to your problem.
If that was not
First of all I don't *have* a problem; certainly not one that is
relevant to this thread. You have created a problem for yourself in
your attempt to prove that my dedicated AC was irrelevant to resolving
noise problem I *had*. Secondly, your explanation was more simpleton
than simple. In the same or similar context, suppose I (or anyone)
offered to you such an absurdly simple explanation to an audio issue
that you presented. Did I find it condescending? You bet I did. But
let me make it clear, it's not because of your simple explanation, per
se. In most any other context offered by anyone else it would have
been simply accepted and dismissed without prejudice. But against the
backdrop of ulterior motives that you have consistently nurtured
throughout this exchange your "simple explanation" was unwelcomed. I
don't trust your motives. See the first paragraph of this response.
>
> >
> > So in either case, there should
> >
> >>not be a higher noise floor just because the wiring is old.
> >
> >
> > "Either" suggests one or the other. You obviously feel very confident
> > about your diagnosis.
>
> Well, I was saying that the older wiring should not cause more 60 cycle
> hum or more white noise if your amps were regulating properly. I would
> love to hear other hypotheses.
OK. That makes sense. But does that assume that the only issue with
the "older wiring" was that it was "old"? Suppose that "older wiring"
had or contributed to other issues. Read *any* of my other posts for
clues.
>
> >Would you bet the farm that you have correctly
> > diagnosed the problem that I had? Would you bet the farm that you were
> > even going in the right direction?
>
> No, why would I? I was just trying to analyse the problem (higher noise
> floor due to old wiring) based on the limited inputs you provided. Which
> by the way may not look like a problem at all.
It's certainly not a problem for me. But let me make it clear again. I
never said that the higher noise floor was due to "old wiring". All I
said was that the wiring was old. In your rush to judgement *you*
jumped to the conclusion that I said or meant that. If I did say that
let me retract that loud and clear. I'm am not certain "why" the old
wiring had a higher noise floor. I am 100% sure, without any doubt,
what so ever, that the noise floor, as emanated through my sound
system, was higher, much higher, than the new circuit.
>
> >I have had highly respected and
> > experienced electricians to be baffled by the layers of wiring that
> > have gone into this house for nearly a century. I'm sure that you can
> > come up with some one sentence rebuttal to show that this is
> > irrelevant to a noise floor. But the point is that you don't have
> > enough information to make even a casual diagnosis. (Actually, you do
> > but you have missed it)
>
> Sure, since all I have is what you have told us, which is very little.
> And I was trying to get more info. Which, of course, you are not
> obligated to give.
Look. I've seen other posts you have contributed and there is no
question that you have decent cognitive skills. But unfortunately you
have allowed your bias' to undermine your abilty to successfully come
to closure on this issue. Perhaps because you don't like the answer.
There is no question that my original post did not answer all the
questions you need to "crack" this dilemma you have created for
yourself. But it provided ample information that, if you read it, even
somewhat carefully, and if you had even a modicum of open mindedness,
you would have been able to ask some relevant, non combative,
questions. But instead you totally the missed that I stated in the
initial post that I had "capacity" issues. You totally missed that the
original AC line is still there and active; a major variable. You
allowed yourself, and continue to allow yourself, to be thrown off the
trail by "gremlins". Your recidivism on that issue is inexcusable. In
addition, you have allowed your "expectation bias", that a new AC
line, rarely, if ever, serves any useful audio related purpose,
completely blind you.
>
> >
> >
> I thought you were sharing your experience with us that going to new
> service cleans up your system noise. It seems like you were making a
> recommendation. Or was I reading you wrong, again?
A "recommendation" is just that, a recommendation. It depends on what
the root condition of the problem that you are trying to address. It
may result in significant improvement as it did for me, or it may not
resolve anything in another system. It is not a cure all. So, yes, in
that light you were reading it wrong *again*.
>
> >
> > So as far as I am concerned, there is no audio
> >
> >>benefit in upgrading the ac power, unless you have a capacity issue.
> >
> >
> > *Unless*. That is such a pesky word.
>
> Why?
Because, I had a capacity issue that I described in my very first
post. You missed this cogent fact. Why? See paragraph one of this
post.
based on the myriad of more
> >>>profound, wide-sweeping claims already made in this thread, if you
> >>>really want to be the gatekeeper on this issue, you have far bigger
> >>>fish to fry.
> >>
>
> >>I don't want to be the gatekeeper on this issue, just like I don't want
> >>to challenge every claim of superior cables. But I thought that you
> >>would have been more interested in figuring out what leads to the lower
> >>noise floor.
> >
> >
> >
> Well, actually I was taking what you said at face value, and trying to
> figure a reason for what you were experiencing.
Curious. Are you any closer now?
>
> > > As a result you glossed
> > over or missed key information. I'm not talking about just the gremlin
> > thing. For example, look at the third paragraph of my initial post. I
> > clearly state that my original AC line is still there and still
> > active. Perhaps, I have plugged my system into it and made
> > comparisons.
>
> OK, so when you plug the system back into the old outlets, do you
> experience a higher noise floor?
Unequivocally yes. But here's another clue. The higher noise was not
there all the time. It also varies in intensity, but never nearly as
loud as I have heard in other systems. But let me make it clear. I
have never plugged the system in to the old line on purpose. I have
done so inadvertently on a couple of occasions. Both outlets are out
of view behind my component cabinet, which is why I made the mistake.
When the noise appears I realize that I have plugged into the wrong
circuit.
Perhaps this has some elements of a "blind test", if you will.
Is it 60-cycle or white noise?
I don't know for a certainty. Remember, until I got the electrical
upgrade I did not even appreciate that I had a noise problem. (This is
not the "gremlin" issue; this is the "acclimation" issue). And the
other times I have experienced the problem it was simply noise to me.
It could have been pink noise (just kidding) as far as I was
concerned. I didn't care. I simply plugged into the correct outlet to
correct the problem. Rehashing this at this moment it appears to have
been 60 cycle noise. But I don't know. But I have given you a lot more
clues now. Perhaps you can tell me what kind of noise it is? Although
at this point you have yet to demonstrate the critical acumen
requisite to objectively resolve your problem.
Why then
> did you say that you could not tell for sure?
And why did you not ask this question about comparing the two lines in
*any* of your first three posts? The question was clearly there to be
asked. I had to hold your hand to lead you to the question.
>
> >You also mentioned that I should not have had a problem
> > with noise *unless* I had a capacity issue. Go back to my initial
> > post. I said *exactly* that; I had a capacity issue.
>
> How did that capacity issue show up as more audible noise? I can see
> circuit breakers being tripped, or some brown-outs, but not something as
> subtle as an elevated noise floor.
Let's see what you do with the new information that I have provided
you. I may answer this question at a later juncture, but I may not.
Unless your amps are not regulating,
> which you seem to reject as a possibility.
OK. You know what amps I use. Let's just assume that that none of my
amps are regulating properly. I doesn't matter. The noise problem does
not exist with the newer circuit; it does exist with the older
circuit. Problem resolved. I'm happy.
>
> >
> > But you also seemed to have a Plan B. If you could not show that I was
> > imagining improvements as a result of my dedicated circuit, Plan B
> > would show that I have crappy equipment.
>
> No, I cannot show that you are imagining things. All I said was that
> there may be some other reasons, other than new wiring, that account for
> your experience. And now that you mention it, imagination is one of
> those reasons.
There is that attitude problem again. You lost a key answer to a
question that you asked due to that remark. Now you say that my
imagination *is* one of those reasons. You have not figured out that
*you* are the one with the colorful imagination and a hyperbolic one
at that. You have mused your way through most of this thread.
>
> >You alluded to that several
> > times. Let me tell you something. You can talk about an audiophiles
> > Mama, but don't talk about his gear!
>
> Actually talking about our gear is a large part of what we do in this
> newsgroup, if you have not noticed.
OK. I stand corrected on this one. But I will explain, if you don't
understand already. I was speaking in the vernacular (look it up).
Used in this way "talk about" is always negative. It is always done to
deride or ridicule. It is to bring the exchange to a personal level,
such as suggesting that a fellow audiophile has or may have poor
quality gear. Again there was a tinge of humor here, which admittedly
some participants may have missed (but I don't think you did),
particularly since the written word has no inflections to assist in
the interpretation. I will remember that in the future. And while you
may already have known all of this, nevertheless, your sarcasm is
warranted and appreciated.
Now for some Mahler.
>
> >
> > Robert C. Lang
> >
> > > >
> >
chung
> chung <chun...@covad.net> wrote in message news:<F7dha.276816$qi4.155148@rwcrnsc54>...
>> Wow, seems like I hit a nerve!
>
> I thought I made that clear. Your motives are suspect to say the
> least. From the beginning you had zero intentions of being "helpful"
> even though you claim that was your original intent.
Wrong. My motivation was, and is, to point out that there may be other
reasons why you perceived "dramatic" noise improvements, and that others
should be wary about such claims about benefits of dedicated AC power.
You took it as a shot at your equipment or at your credibility.
>You have this a
> mission to contradict or to somehow prove that I had no noise problem
> at all let alone a noise problem that was resolved by an electrical
> upgrade.
You seem to be the one who is not really sure whether there was a nosie
problem. You did not know whether it was line related, or broadband. You
did not know whether it was coming from preamps or power amps. All I did
was ask a couple of questions and present a couple of possibilities, and
try to figure out the technical reasons for what you were experiencing.
>We both know it.
Please speak for yourself only.
>But that is perfectly OK. It is my choice to
> engage in this exchange with you. Were're clearly both enjoying it.
Except when you seem to sense that others have doubts about your equipment.
> Hey, I'm taking time to respond to your post and have postponed for a
> bit to listent to Mahler's 6th. We at least we know where each of us
> is coming from.
Actually, I don't know where you are coming from and where you are
going, or why. It is obvious that I already missed your attempt at humor.
>By the way, I do provide you some more clues, most
> which you should have been able to figure out on your own if you were
> more attentive to my initial post.
You said you have no interest in figuring out the reasons why
you were hearing better noise floors, so I will refrain from asking you
any more questions!
>Enjoy.
Always.
Robert Lang
> Robert Lang wrote:
> My motivation was, and is, to point out that there may be other
> reasons why you perceived "dramatic" noise improvements, and that others
> should be wary about such claims about benefits of dedicated AC power.
I think you have a lot to offer in this area. You have certainly
peaked my interest in a couple of areas. You are correct. People
should be wary about claims of benefit too often attributed to
dedicated AC power. Sometimes it can help address issues, but perhaps
most of time it will be of little or no benefit depending on the
circumstances of the individual user. It seems that some audiophiles
may use dedicated AC lines as part of a shotgun approach to deal with
problems that may or may not exist.
I have a suggestion. Perhaps it would be helpful if you directed your
questions and advice to the top of the thread. Specifically, address
them to the poster who initially requested assistance and
recommendations about dedicated AC power.
Or better yet, at this point, for a wider audience, create a new
thread about the topic. You could offer general advice to the group as
a whole on this often discussed topic. What are the myths? When should
a dedicated AC power should be considered? When should it be dismissed
as an option? What does 60 cycle noise tell you about a problem? How
to figure out if you have a capacity problem? What does excessive
white noise tell you? How do ground loops figure into the equation?
Can certain appliances or lights trigger problems for audiophiles?
What design features does one look for in gear that will help minimize
line noise. Perhaps importantly, how does costs factor into the
decision making process for opting for a dedicated AC line? As part
of the upgrade to my house from 50 amps (approximately) to 200 amps
the electrician installed a dedicated line for my video studio at no
cost at all. My dedicated line which I ended up using for my audio
system, cost under $150 due to easy access, but in some situations a
dedicated line can cost far more.
I'm sure for every question I have posed here you could pose and
answer many more.
Robert C. Lang
chung
OK, I'll make it simple. There are a large number of audiophiles who
over-estimate the difficulty of home audio reproduction. Dedicated AC
power lines are not necessary unless there is a capacity issue. Are your
circuit breakers tripping? Do your lights blink when you turn your
stereo on? Does any of your equipment reset when the refrigerator's
compressor kicks in? Do you have grounded outlets?
IF you do not have a capacity problem, meaning you don't observe any of
the above or similar things, there really is no reason to install a new
AC service *just* to power your audio system. If you are adding new
service or upgrading existing service for other reasons, it sure is nice
to allocate a separate circuit (controlled by its own breaker) for your
AV system, for capacity and expandablity reasons.
I have yet to find a ground loop problem that requires a new dedicated
service to fix. For other noise problem, troubleshoot to isolate
problem. There may be a cuplrit (like a dimmer that causes too much AC
line noise) that is easily identifiable, and all you need to do is to
replace that or put that on a different circuit.
If your system is quiet and does not exhibit capacity problems, don't
look for ways to spend money to get any incremental advantage.
Mike Gilmour
news:HQwha.285902$6b3.1...@rwcrnsc51.ops.asp.att.net...
> > Noise problem aren't always heard from the speakers. Before I plugged my
> system into a dedicated AC line, the power transformer--not the driver--on
> my powered subwoofer hummed loudly enough to be heard all the way across
the
> room. The culprit was a table lamp with a compact fluorescent bulb.
> Charlie G
>
I understand certain lighting dimmers on the same circuit cause similar
problems.
Dedicated AC power is very cost effective if you are able to to the
installation yourself. Do not tackle this job yourself unless you are 100%
aware regarding safety and installation.
In response to e-mails I've received there are certain (UK) IEEE regulations
governing the installation of a second (dedicated) consumer unit. To my
understanding if the meter tails are more than 3M then a fused two pole
isolator switch must be mounted on the meter board to feed a correctly sized
sub-mains to the additional consumer unit. If its a SWA sub-mains use three
core so you don't rely on the armour for a through earth connection, however
do make sure that the armour is also grounded.
Advise your electric supply company first as connecting into the meter tails
safely means the removal of the incoming electric company seal and fuse. Use
a Henley block to connect the new tails. On inspection (usually by the meter
reader) if your installation abides by regulations then the electric company
will allow connection & fit new seal/s.
I also use ferrite rings on outlets from the consumer units to
attenuate/kill RFI (expecting 'flames' on this one) and a connection to an
exterior earth spike a supplement to the house earth.
You can go the easier route and take spurs from your existing CU, to my
experience this is generally better than the domestic ring-main but not as
good as a dedicated supply direct from the incoming feed.
From the threads this seems a very contentious issue. My experience of
installations effectiveness is system, location dependent. High end systems
have all gained - especially where CD players / DACs etc. are on a seperate
circuit (make of that what you will).
Mike Gilmour
chung
> >
> From the threads this seems a very contentious issue. My experience of
> installations effectiveness is system, location dependent. High end systems
> have all gained - especially where CD players / DACs etc. are on a seperate
> circuit (make of that what you will).
>
>
If that is true, then a simple measurement of S/N, frequency response,
distortion, etc. should reveal the improvements (or at least the
differences) before and after. Has this ever been done to validate the
perceived differences?
Why is it that high-end systems have gained, more so than medium-end?
Could it be that the "mid-fi" systems are actually better designed when
it comes to power line radiation and susceptibilty? The
mass-manufacturers probably have to make sure that the products pass FCC
Class B requirements, or the equivalent standards worldwide. Is there a
similar requirement on the "high-end" (i.e. low-volume) products? Are
the requirements different in the U.K.?
Mike Gilmour
> Mike Gilmour wrote:
> > >
> > From the threads this seems a very contentious issue. My experience of
> > installations effectiveness is system, location dependent. High end
systems
> > have all gained - especially where CD players / DACs etc. are on a
seperate
> > circuit (make of that what you will).
> >
> >
>
> If that is true, then a simple measurement of S/N, frequency response,
> distortion, etc. should reveal the improvements (or at least the
> differences) before and after. Has this ever been done to validate the
> perceived differences?
Not to my knowledge though I would be very interested to learn more. A good
university thesis could come out of this.
> Why is it that high-end systems have gained, more so than medium-end?
> Could it be that the "mid-fi" systems are actually better designed when
> it comes to power line radiation and susceptibilty? The
> mass-manufacturers probably have to make sure that the products pass FCC
> Class B requirements, or the equivalent standards worldwide. Is there a
> similar requirement on the "high-end" (i.e. low-volume) products? Are
> the requirements different in the U.K.?
>
It could well be that the 'mid-fi' market are subject to more stringent
legislation in regard to power line radiation & susceptibility than the low
volume high-end products. European legislation has wrought many changes in
the UK recently, so if this is the case I'm sure it will soon be
addressed - can anyone answer this one with more clarity?
High end systems IMHO are overly sensitive to mains. I find the very best
listening times are inconveniently in the early hours of the morning. This
could be due to bad PSU design or possibly high end systems may reveal
changes hidden by mid-fi systems. One advantage of a mid-fi system is
that whenever it is used it generally sounds okay. Some high-end systems
unfortunately suffer changes in performance for no apparent reason. Why
exactly I have never found out, theories are bandied about like RFI, mains
loading, mains signalling (?) temperature, god?
I suspect the anti high-end brigade will say its all due to bad equipment
design. Of the many systems I've heard and of the various listener reports I
really can't believe this can always be the case.
Mike
chung
And the pro-high-end brigade will say that it's because high-end
equipment is more revealing, so there you go... :)
>Of the many systems I've heard and of the various listener reports I
> really can't believe this can always be the case.
>
Actually, apart from tube amps and perhaps poorly designed DAC's, I do
not find that the audio performance changes noticeably over time.
> Mike
>
David Power
wrote:
>Has anyone had an electrician install a dedicated AC power line in their
> home for Audio?? Is it worth the effort??
I have had several experiences and I probably will get slammed by
chung but here goes.
I have a house built in the early 80's 100-amp service. Outlets in my
living room were shared buy circuits that also run into my kitchen.
There were no compact fluorescent no dimmers and none of the usual
culprits that are listed as gremlins in power line problems.
I wasn't blowing fuses or tripping breakers.
I decided to add a 20 amp dedicated line to my system because I could
see the led's dim when the air conditioning turned on or the microwave
or oven was turned on. After the installation, the most noticeable
thing was, unless the system was turned up quite loudly, I could no
longer tell it was turned on. The very low level hiss that I was used
to was now gone.
This was a system that used mid 80's technics professional amps and
phase liner front-end with Magnapan 2 series for speakers.
Dynamics were slightly improved but the most noticeable reduction was
that the noise levels with the system idle dropped.
Move forward 10 years.
Same room, same power. 1 dedicated outlet (12 gauge), 1 shared on
additional branch circuits (12 gauge)
I now have a system using VTL 750 mono blocks for the fronts and
Maggie 20.1 as the main speakers in a surround sound setup. If I turn
on the amps to quickly while the front end is on I blow a breaker
(good indication that something isn't right). If the microwave in the
kitchen is used while the system is on, lights out once again. If the
surround sound system was on and the sound track got loud the sound
stage collapsed the center channel became hard to understand. The
lights in the room would pulse to the beat if things got slightly
loud( 80-90 db on a radio shack sound meter).
I upgraded the house to a 200-amp panel and feed which fixed the
ceiling lights dimming problem, but I still noticed problems when
things got loud or I was running a lot of gear.
Time to drag out the current meter and my digital o scope.
Monitoring the main dedicated line (12 gauge, which I had the amps
plugged into) I could watch the current peak and the voltage drop as I
played music at reasonable listening levels (my wife and I could have
a conversation in the room at the time).
I could also see considerable ringing as various transformers
reflected back into the line during loud passages. Monitoring the line
feeding the front end (which is shared by several kitchen outlets)
extensive ringing could be seen if the microwave or any number of
appliances were turned on.
Time for Power upgrade #2. I ran 3 new 20 amps 10 gauge stranded
lines. I now had 3 dedicated 10 gauge circuits and 1 dedicated 12
gauge with 1 shared 12 gauge branch circuit.
I distributed the 5 amps and 4 subs with built in amps on the new
circuits and ran the front end on the 12-gauge dedicated circuit and
used the shared circuit for lamps.
Monitoring the system with an amp probe and o scope shows a
significantly decreased dip in voltage and current during loud
passages (but they are still visible and measurable).
The system sounds considerably more dynamic and quiet at the same
time, I can now turn the pre amp up to the 75% range before I can hear
the system at idle. The lights no longer dim and the leds no longer
flicker. Watching the power lines and using a power meter I no longer
see the big fluctuations that I used to see.
Total cost was just over $1600 for the new panel, the new branch
circuits and the new main line to the transformer. I believe it was
worth every penny.
I'm am planning an even more extensive power system in my new house
for my music room and I'm interested in seeing what I end up with.
David Power
Katy Tx.
Mike Gilmour
>
>
> Actually, apart from tube amps and perhaps poorly designed DAC's, I do
> not find that the audio performance changes noticeably over time.
I do, apart from the tube warm up/settling time of 20 mins (approx) I've
found that performance can suffer marginally in periods of increased supply
loading and sound exceptionally good during late night/early morning (no
near neighbours - luckily).
chung
Someone once told me that his vinyl system sounded the best at night
when he was drowsy, preferably after a couple of glasses of wine.
chung
> On Thu, 27 Mar 2003 01:46:41 GMT, mfr <mikeru...@earthlink.net>
> wrote:
>
>>Has anyone had an electrician install a dedicated AC power line in their
>> home for Audio?? Is it worth the effort??
>
> I have had several experiences and I probably will get slammed by
> chung but here goes.
Slammed by me? You must be joking :).
> I have a house built in the early 80's 100-amp service. Outlets in my
> living room were shared buy circuits that also run into my kitchen.
> There were no compact fluorescent no dimmers and none of the usual
> culprits that are listed as gremlins in power line problems.
> I wasn't blowing fuses or tripping breakers.
>
> I decided to add a 20 amp dedicated line to my system because I could
> see the led's dim when the air conditioning turned on or the microwave
> or oven was turned on. After the installation, the most noticeable
> thing was, unless the system was turned up quite loudly, I could no
> longer tell it was turned on. The very low level hiss that I was used
> to was now gone.
You had a mild case of under-capacity. It would have been very useful to
isolate the low-level hiss to a specific component. IOW, is it the
preamp, or is it the power amp.
> This was a system that used mid 80's technics professional amps and
> phase liner front-end with Magnapan 2 series for speakers.
> Dynamics were slightly improved but the most noticeable reduction was
> that the noise levels with the system idle dropped.
> Move forward 10 years.
>
> Same room, same power. 1 dedicated outlet (12 gauge), 1 shared on
> additional branch circuits (12 gauge)
>
> I now have a system using VTL 750 mono blocks for the fronts and
> Maggie 20.1 as the main speakers in a surround sound setup. If I turn
> on the amps to quickly while the front end is on I blow a breaker
> (good indication that something isn't right). If the microwave in the
> kitchen is used while the system is on, lights out once again. If the
> surround sound system was on and the sound track got loud the sound
> stage collapsed the center channel became hard to understand. The
> lights in the room would pulse to the beat if things got slightly
> loud( 80-90 db on a radio shack sound meter).
I am a little confused. You are saying that 20 years later you had
developed a major capacity problem with your dedicated AC line that
supposedly only powered the AV? If you can blow a breaker (you mean
trip?) you have a significant problem. Did that happen when the incoming
level was high (i.e. loud)? Have you tried a different power amp that
has the same output wattage? Perhaps talking to VTL would help there,
since it appears that those monoblocks have huge in-rush currents.
>
> I upgraded the house to a 200-amp panel and feed which fixed the
> ceiling lights dimming problem, but I still noticed problems when
> things got loud or I was running a lot of gear.
> Time to drag out the current meter and my digital o scope.
Is it still a 20 amp circuit that powers the AV?
>
> Monitoring the main dedicated line (12 gauge, which I had the amps
> plugged into) I could watch the current peak and the voltage drop as I
> played music at reasonable listening levels (my wife and I could have
> a conversation in the room at the time).
What are the magnitudes of the drops? This is quite unusual if the drops
are large (>2V). I would have expected a couple of volts at the most if
you are not playing loud. 12 guage wire has a resistance of 1.7 milliohm
per foot. Assuming you have a run of 50 ft., you have a total
resistance of 85 milliohms. Each amp of current develops 85 millivolt
drop. 20 amps give 1.7V drop, which is the limit of the circuit I
assume. It also depends on how you measure, since there is an equal drop
in the neutral lead. Each amp is equivalent to 115 watt of power used.
You can figure out how much current you are drawing by observing the
drop (the steady-state portion, or that read by a DVM, and not the
ringing which depends on instantaneous currents). Sounds like you had a
problem. Do you have a really long run of AC lines? Now any hi-fi
product that fails to regulate when the incoming line voltage fluctuates
by a couple of volts is not designed right.
> I could also see considerable ringing as various transformers
> reflected back into the line during loud passages. Monitoring the line
> feeding the front end (which is shared by several kitchen outlets)
> extensive ringing could be seen if the microwave or any number of
> appliances were turned on.
>
I thought you said you had a dedicated line. Are you saying that the
appliances are on the same circuit, or different circuits?
> Time for Power upgrade #2. I ran 3 new 20 amps 10 gauge stranded
> lines. I now had 3 dedicated 10 gauge circuits and 1 dedicated 12
> gauge with 1 shared 12 gauge branch circuit.
10 ga. wire has 1 milliohm per foot.
>
> I distributed the 5 amps and 4 subs with built in amps on the new
> circuits and ran the front end on the 12-gauge dedicated circuit and
> used the shared circuit for lamps.
> Monitoring the system with an amp probe and o scope shows a
> significantly decreased dip in voltage and current during loud
> passages (but they are still visible and measurable).
So no appliances on that circuit I assume. What are the magnitudes of
the drops?
> The system sounds considerably more dynamic and quiet at the same
> time, I can now turn the pre amp up to the 75% range before I can hear
> the system at idle. The lights no longer dim and the leds no longer
> flicker.
So now you have ample capacity and you did not have enough before. Good
for you.
Watching the power lines and using a power meter I no longer
> see the big fluctuations that I used to see.
> Total cost was just over $1600 for the new panel, the new branch
> circuits and the new main line to the transformer. I believe it was
> worth every penny.
OK. I would say that your experience is not all that common since I
seldom see circuit breakers trip when one turns on the power amp. Wait,
how did you install a main line to the transformer?
> I'm am planning an even more extensive power system in my new house
> for my music room and I'm interested in seeing what I end up with.
>
Dare I say "expectation bias"?
> David Power
> Katy Tx.
>
chung
>
> Total cost was just over $1600 for the new panel, the new branch
> circuits and the new main line to the transformer. I believe it was
> worth every penny.
You just made an excellent point. Those pondering the purchase of
expensive cables and interconnects should seriously think about
upgrading electrical service first. For the same kind of cash outlay,
you have the same perceived advantages (lower noise, more dynamics,
better control, etc.) with the undeniable, *measureable* improvement of
higher capacity.
Off-topic rant: For me, the best upgrade for that kind of money is to
buy a 20 inch LCD monitor. It gives you a much better outlook on
everything. I can't stand it when my audiophile friends spent big bucks
on cables and DAC's, and are squinting in front of that old 15 inch CRT
monitor where they spend more of their time. Rant finished.
Robert Lang
> On Thu, 27 Mar 2003 01:46:41 GMT, mfr <mikeru...@earthlink.net>
> wrote:
>
> >Has anyone had an electrician install a dedicated AC power line in their
> > home for Audio?? Is it worth the effort??
>
> I have had several experiences and I probably will get slammed by
> chung but here goes.
> I have a house built in the early 80's 100-amp service. Outlets in my
> living room were shared buy circuits that also run into my kitchen.
> There were no compact fluorescent no dimmers and none of the usual
> culprits that are listed as gremlins in power line problems.
> I wasn't blowing fuses or tripping breakers.
>
> I decided to add a 20 amp dedicated line to my system because I could
> see the led's dim when the air conditioning turned on or the microwave
> or oven was turned on. After the installation, the most noticeable
> thing was, unless the system was turned up quite loudly, I could no
> longer tell it was turned on. The very low level hiss that I was used
> to was now gone.
This entire experience so much parallels my own (see 4th post of
thread). My component cabinet, had fluorescent lights that contributed
to noise issues (evidenced by turning them on or off). My amps have
protection circuitry that remain active for about 15-20 seconds after
powering on. Deactivation of the protection circuitry is evidenced by
an audible "click" from the amps and the illumination of green LEDs.
Before I installed the dedicated 20 amp line after deactivation of the
protective circuitry, low level but clearly audible noise clicked in.
I believe this was a combination of white noise and hum (buzz). After
the installation of the dedicated circuit, when the protective
circuitry "clicked" off the noise was present but greatly reduced. At
normal volume settings, at idle, I detect a smidgen of white noise and
a smidgen of hum. The noise is not audible, to me, even at quiet
musical passages.
A primary difference between your experience and mine is that your
line upgrade was intelligently planned. My line upgrade was "dumb"
luck. I had no idea that I was about to experience a dramatic lowering
of the noise floor. My old line is still active and I have confirmed
the improvement by plugging my system into the old line, albeit by
accident. Is your old line still active? Have you utilized it for
your system after installation of the dedicated line?
Robert C. Lang
> This was a system that used mid 80's technics professional amps and
> phase liner front-end with Magnapan 2 series for speakers.
> Dynamics were slightly improved but the most noticeable reduction was
> that the noise levels with the system idle dropped.
> Move forward 10 years.
>
> Same room, same power. 1 dedicated outlet (12 gauge), 1 shared on
> additional branch circuits (12 gauge)
>
> I now have a system using VTL 750 mono blocks for the fronts and
> Maggie 20.1 as the main speakers in a surround sound setup.
Sounds awesome. I would love to hear your system. Knowing that this is
not likely I would love to know more about it, as I am building a
surround system.
> Total cost was just over $1600 for the new panel, the new branch
> circuits and the new main line to the transformer. I believe it was
> worth every penny.
This is not to far different from the cost I had to shell out for my
upgrade to 200 amps (and I'm in the San Francisco Bay Area). Also, as
the electrician was finishing up the job, I made a last minute request
to add an a second new circuit to my video production studio. He did
so at no added cost. A year or two later I added the circuit, that I
have dedicated to my audio system. It cost $125. If you need them
these upgrades can be an audio bargain.
Robert C. Lang
C. Leeds
> ...Now any hi-fi
> product that fails to regulate when the incoming line voltage fluctuates
> by a couple of volts is not designed right.
This is true, provided that there is no problem with the quality of the
incoming AC line in the first place. That's a m-a-j-o-r assumption, however.
Chung seems to think that if a user has "200A electrical service," that
it means the utility can deliver 200A of current at the service panel.
That can be a very faulty assumption that can only be proven with a
"beast-of-burden" test. Note that in many states the utility can fail
that test without consequence.
C. Leeds
> ... Dedicated AC
> IF you do not have a capacity problem, meaning you don't observe any of
> the above or similar things, there really is no reason to install a new
> AC service *just* to power your audio system.
This is completely false, of course, as has been shown in this thread.
In particular, problems with grounding and voltage drop indicate
probable benefits from dedicated AC lines. It's puzzling why "Chung"
chooses to ignore these simple facts. Perhaps he simply seeks an argument.
chung
> chung wrote:
>
> > ...Now any hi-fi
>> product that fails to regulate when the incoming line voltage fluctuates
>> by a couple of volts is not designed right.
>
> This is true, provided that there is no problem with the quality of the
> incoming AC line in the first place. That's a m-a-j-o-r assumption, however.
If the quality of the incoming AC service is poor, can adding a circuit
help? I would assume that it is the same incoming AC quality. Unless you
have a totally new AC feed from the utility company.
>
> Chung seems to think that if a user has "200A electrical service," that
> it means the utility can deliver 200A of current at the service panel.
> That can be a very faulty assumption that can only be proven with a
> "beast-of-burden" test. Note that in many states the utility can fail
> that test without consequence.
No, I was thinking that if one has a 20 amp circuit installed, then that
circuit should be able to deliver 20 amps.
If the utilty company fails to deliver 200A's, then that would be a
problem *if* the actual usage is close to 200A's. Are you saying that
the utility often fails to deliver a fraction of the 200A's and maintain
line voltage?
Nousaine
>> ... Dedicated AC
>> power lines are not necessary unless there is a capacity issue. Are your
>> circuit breakers tripping?...
>> IF you do not have a capacity problem, meaning you don't observe any of
>> the above or similar things, there really is no reason to install a new
>> AC service *just* to power your audio system.
IME this is 100% the case. I've lived in 5 houses over the past 20 years with
all sorts of multiple audio systems and workstations. Presently I have 2
sophisticated multichannel systems (one includes a DIY subwoofer that will
produce 120 dB from 12 to 62 Hz @ 2 meters in the room) and 3 measurement work
stations (one of which uses a 5000 watt power amplifier to test car subwoofers)
and have never felt the need for dedicated AC. Indeed I have never once tripped
a 15 or 20 amp breaker in the 150 amp service box, although occasionally (2 or
3 times in 6 years) I've dropped a 15-amp breaker on the outlet strip that
feeds measurement gear (not the amplifiers.)
I did install dedicated AC circuits for power amplifiers in a DIY sound
isolated room in my first house but found they really didn't perform any better
than any other ciruit in that or any other place.
Ground loops and noise are handled with good installation techniques and seldom
an issue except for the occasional initial set-up with a new piece of gear. I
can't see how a dedicated line would be useful in that regard either.
Robert Lang
> everything. I can't stand it when my audiophile friends spent big bucks
> on cables and DAC's, and are squinting in front of that old 15 inch CRT
> monitor where they spend more of their time. Rant finished.
Rant Part 2.
I agree. I don't have the good fortune to have the incredible 20
incher (Is it the Apple Cinema?). But I do have dual 18 inchers. One
great thing about using good dual LCD screens compared to conventional
CRTs is that the real estate flows better from one screen to the next.
In either case you will have the broken real estate in the middle of
your viewing area. (Although you learn to have your modules neatly
tucked inside each monitor for maximum viewing comfort). But the break
with the flat screens is *far* less abrut, both in width and in depth.
You have more of a feeling that you are working with one huge screen
as opposed to two large clunky 20th century CRT monitors. And there is
the "cool" factor, which frankly, I did not really appreciate until my
clients whom have seen these LCD beauties brought it to my attention.
Some of the faults of earlier generation LCDs, such as noticeably
lower resolution, and poor off axis viewing have been licked with the
latest generation LCDs. But on the other hand, I understand that with
super duper hi-rez applications that CRTs are still the way to go. But
at a minimum a good LCD should be considered.
Robert C. Lang
chung
> chung wrote:
>> ... Dedicated AC
>> power lines are not necessary unless there is a capacity issue. Are your
>> circuit breakers tripping?...
>> IF you do not have a capacity problem, meaning you don't observe any of
>> the above or similar things, there really is no reason to install a new
>> AC service *just* to power your audio system.
>
> This is completely false, of course, as has been shown in this thread.
If that's the case, where is the measurement data that supports your
opinion? I have said that going to dedicated power is not unnecessary
unless there is capacity issues. In several of those testimonials, there
were capacity problems. There are also testimonials that people have no
need to have dedicated AC to keep the noise floor acceptably low. The
point I am making is that there are other ways to attack ground loop
problems or other interference problems, and upgrading AC should be a
last resort.
> In particular, problems with grounding and voltage drop indicate
> probable benefits from dedicated AC lines.
Can those "probable" effects be measured? Can the other causes of
degradation be eliminated without rewiring the AC? Can those grounding
issues be fixed more intelligently? I'll repeat my statement that I have
not found a ground loop that I cannot remove.
>It's puzzling why "Chung"
> chooses to ignore these simple facts. Perhaps he simply seeks an argument.
I was not ignoring those testimonials. I was asking for more
information. Those were not "simple facts". Well, maybe simple facts to
you, but certainly not to me and to other people. For me, I have never
found a need to upgrade AC to keep noise low, so the "simple fact" to me
is you don't need it. Mr. Robert Lang asked for my opinion, and I
provided it. Is that what you meant by seeking an argument?
chung
> chung <chun...@covad.net> wrote in message X> Off-topic rant: For me, the best upgrade for that kind of money is to
>> buy a 20 inch LCD monitor. It gives you a much better outlook on
>> everything. I can't stand it when my audiophile friends spent big bucks
>> on cables and DAC's, and are squinting in front of that old 15 inch CRT
>> monitor where they spend more of their time. Rant finished.
>
> Rant Part 2.
>
> I agree. I don't have the good fortune to have the incredible 20
> incher (Is it the Apple Cinema?).
It's the Dell 20.1 inch LCD. 1600X1200 resolution. I have seen them go
for as low as $800 shipped from Dell. You need a video card with DVI, or
should use one, and that sets you back all of $100.
It's the least one can do to preserve one's eyesight, if one spends
significant time using the computer.
David Power
>isolate the low-level hiss to a specific component. IOW, is it the
>preamp, or is it the power amp.
It would be hard to say. That was over ten years ago and I wasn't as
picky as I am now. The capacity of the system to stress the lines was
significant but not nearly what I can do now.
>I am a little confused. You are saying that 20 years later you had
>developed a major capacity problem with your dedicated AC line that
>supposedly only powered the AV? If you can blow a breaker (you mean
>trip?) you have a significant problem. Did that happen when the incoming
>level was high (i.e. loud)? Have you tried a different power amp that
>has the same output wattage? Perhaps talking to VTL would help there,
>since it appears that those monoblocks have huge in-rush currents.
No, it was 20 year old rebuilt equipment but this was only ten years
or so ago. The line that I had at the time was shared with several
kitchen circuits. I added a dedicated line for the music system and
still used the shared system. I could trip the shared breaker at will,
either by playing very loud music or turning on a lot of gear using a
switcher. The amps I was using at the time were rated at 100 watts
into 8 ohms but would push 195 into 4 and 350 into 2 ohms. They
weighed over 50lbs each. Over speced pro gear designed to run into
hostile loads for a long time and extreme volumes.
The current system amps use a 2 stage turn on to help prevent major
inrush surges. If the mains blip, I blow the breakers and several
fuses because of the inrush.
I have 3- 750 tube watt amps, 5 subs w 300 watt amps 2- 450 watt tube
amps, plus the front end gear and the rptv in that room. It does have
a bit of inrush.
>>
>> I upgraded the house to a 200-amp panel and feed which fixed the
>> ceiling lights dimming problem, but I still noticed problems when
>> things got loud or I was running a lot of gear.
>> Time to drag out the current meter and my digital o scope.
>
>Is it still a 20 amp circuit that powers the AV?
At that time it was still a dedicated 20 amp and a shared 15amp, I
upgraded the panel and the feed back to the transformer, I replaced
the transformer feed with a stranded copper line, it had been a solid
aluminum line.
>>
>> Monitoring the main dedicated line (12 gauge, which I had the amps
>> plugged into) I could watch the current peak and the voltage drop as I
>> played music at reasonable listening levels (my wife and I could have
>> a conversation in the room at the time).
>
>What are the magnitudes of the drops?
10 to 12 volts max 3-5 normally, this is with a 200 mhz scope, a volt
meter hardly shows a flicker.
>This is quite unusual if the drops
>are large (>2V). I would have expected a couple of volts at the most if
>you are not playing loud. 12 guage wire has a resistance of 1.7 milliohm
> per foot. Assuming you have a run of 50 ft., you have a total
>resistance of 85 milliohms. Each amp of current develops 85 millivolt
>drop. 20 amps give 1.7V drop, which is the limit of the circuit I
>assume.
Ill take your word for that, I don't have a ohm meter that's that
sensitive.
>It also depends on how you measure, since there is an equal drop
>in the neutral lead. Each amp is equivalent to 115 watt of power used.
>You can figure out how much current you are drawing by observing the
>drop (the steady-state portion, or that read by a DVM, and not the
>ringing which depends on instantaneous currents). Sounds like you had a
>problem. Do you have a really long run of AC lines?
30 to 50 ft
>Now any hi-fi
>product that fails to regulate when the incoming line voltage fluctuates
>by a couple of volts is not designed right.
Most amps don't regulate at all they just pile on caps which don't
have much affect as far as I can tell on line voltage, just amperage
drops.
>> I could also see considerable ringing as various transformers
>> reflected back into the line during loud passages. Monitoring the line
>> feeding the front end (which is shared by several kitchen outlets)
>> extensive ringing could be seen if the microwave or any number of
>> appliances were turned on.
>>
>
>I thought you said you had a dedicated line. Are you saying that the
>appliances are on the same circuit, or different circuits?
I had the amps plugged into the dedicated circuit the front end was
using the shared circuit.
>> Time for Power upgrade #2. I ran 3 new 20 amps 10 gauge stranded
>> lines. I now had 3 dedicated 10 gauge circuits and 1 dedicated 12
>> gauge with 1 shared 12 gauge branch circuit.
>
>10 ga. wire has 1 milliohm per foot.
ok
>>
>> I distributed the 5 amps and 4 subs with built in amps on the new
>> circuits and ran the front end on the 12-gauge dedicated circuit and
>> used the shared circuit for lamps.
>> Monitoring the system with an amp probe and o scope shows a
>> significantly decreased dip in voltage and current during loud
>> passages (but they are still visible and measurable).
>
>So no appliances on that circuit I assume. What are the magnitudes of
>the drops?
The system except for lighting is all on dedicated circuits now, The
voltage variation measured with the scope is now around 2 volts.But I
do see the mains voltage vary by 6 to 8 volts based by time of day
and day of the week .
>> The system sounds considerably more dynamic and quiet at the same
>> time, I can now turn the pre amp up to the 75% range before I can hear
>> the system at idle. The lights no longer dim and the leds no longer
>> flicker.
>
>So now you have ample capacity and you did not have enough before. Good
>for you.
> Watching the power lines and using a power meter I no longer
>> see the big fluctuations that I used to see.
>> Total cost was just over $1600 for the new panel, the new branch
>> circuits and the new main line to the transformer. I believe it was
>> worth every penny.
>
>OK. I would say that your experience is not all that common since I
>seldom see circuit breakers trip when one turns on the power amp. Wait,
>how did you install a main line to the transformer?
The electricians dug a trench and ran a new stranded copper line to
the meter.
>> I'm am planning an even more extensive power system in my new house
>> for my music room and I'm interested in seeing what I end up with.
>>
>
>Dare I say "expectation bias"?
If my experiences are any indication its similar to the expectation of
buying a v-8 vs a straight 4.
I'm also putting in a isolation transformer to supply "balanced power"
to the circuits. All lines to the amps and subs are 10 gauge stranded.
Ill be measuring these lines referenced to the standard mains as the
construction progresses.
David Power
Katy Tx.
bl...@vnet.ibm.com
>problems or other interference problems, and upgrading AC should be a
>last resort.
And why would that be? Take my case where the existing circuit was
daisy chained through a bunch of outlets using spring clips that made
poor enough contact for unused outlets to heat up under heavy load.
And ground connections are made by crimping a copper sleeve around
the wires, sometimes so loose that it can be moved by hand.
Sure, that circuit could be fixed up to handle the load without strain.
I could locate every outlet on the circuit, clean up all those
tarnished 20-year old wires, and move all the connections to the
screw terminals on the outlets (which would also need cleaning).
But why? I'll bet it would be more work than putting in my two new
circuits was (one for the system and one for the air conditioner).
The lamps that are still on it don't really need it fixed. New circuits
certainly seemed like the better choice to me.
Bob
Mike Gilmour
> David Power wrote:
> Off-topic rant: For me, the best upgrade for that kind of money is to
> buy a 20 inch LCD monitor. It gives you a much better outlook on
> everything. I can't stand it when my audiophile friends spent big bucks
> on cables and DAC's, and are squinting in front of that old 15 inch CRT
> monitor where they spend more of their time. Rant finished.
My Rant: All my audiophile friends don't even bother with 'squinting in
front of that old 15 inch CRT' as they have high end stereo systems which
they are mostly content with. They are not at all interested in TV, home
cinema, surround sound, 5.1 or whatever you will. They feel as I do, we've
seen the Hi Fi shows home cinema dems, Home Cinema Salons et al and are fed
up with explosions, helicopter crashes 'impressive' but ultimately deadly
boring displays. This has nothing at all to do with reproducing music
faithfully, which is and always has been our aim. We don't want to even try
to emulate a cinema complex in the home. In most complexes the sound is
mostly and relentlessly overcompressed with overly 'impressive' (again read
boring) sub activity. Rant finished.
We have all installed dedicated mains because our systems all sound
considerably better. No we haven't done it because of any tripping problems,
grounding problems. The wide-band noise reduction came as a bonus as non of
us had any perceivable hum problems except from occasional transfomer noise
(which was eliminated by the upgrade) No we don't have any exact
difference measurements ... it just sounds a lot better and all in all a
very cost effective upgrade, far cheaper than a 'big bucks cable' - period.
chung
Sure, in your case it makes sense to upgrade, but not only for audio
purposes. You have a potential reliability issue and perhaps even a
safety issue. I also upgraded my services, but the intent was not to
improve audio.
Robert Lang
Now any hi-fi
> product that fails to regulate when the incoming line voltage fluctuates
> by a couple of volts is not designed right.
Your post was way over my head (my problem), so I have zeroed in on a
sentence that I can understand. I have a series of closely related
questions pertaining to "regulation".
What are example of amps, especially lower cost amps, that regulate?
Are they the exception or the rule? What are examples of amps that
don't regulate? Is this a feature that is usually advertised? How is
a consumer to know? Do some amps regulate better than others?
If one owns an amp that he or she likes, but that amp does not
regulate and there are known AC line issues, i.e. capacity issues,
could it be a plausible solution, depending on cost, to install a
dedicated circuit for you audio system?
My amp, the Nuvista 300, has a "regulated choke supply", which may or
may not have anything to do what we are talking about. This is a 110
pound unit, of which 50 Lbs are devoted to the power supply (PSU) and
"choke regulation". Based on what you know, is this an amp that
regulates with respect to incoming line voltage fluctuations? By the
way, I will not take offense to your response now that I have a little
better understanding what you are talking about?
Finally, I employ a passive line stage (passive pre). Of course, there
is no power supply, no regulation. How does a passive pre fit into the
equation?
Robert C. Lang
Richard D Pierce
Robert Lang <Rober...@msn.com> wrote:
>My amp, the Nuvista 300, has a "regulated choke supply", which may or
>may not have anything to do what we are talking about. This is a 110
>pound unit, of which 50 Lbs are devoted to the power supply (PSU) and
>"choke regulation". Based on what you know, is this an amp that
>regulates with respect to incoming line voltage fluctuations?
A "choke regulator" is not a regulator at all. It is simply a
line ripple filter. The power supply output will be directly
proportional to the AC voltage input. If the rest of the circuit
has poor power supply rejection properties, an unfortunately
all-to-common characteristic of a lot of high end stuff (single
ended amplifiers could well be EXTREMELY sensitive to simply
line coltage variations), then, indeed, there could be audible
changes.
But this is an indictment of the failure to adequately design
the amplifier, NOT "evidence" that the amplfier is more
transparent.
An amplifier is NOT SUPPOSED TO BE TRANSPARENT TO LINE VOLTAGE
ISSUES! That's not it's job. Who on earth in their right mind
would could make such a claim with a straight face? AN
amplifier's job is to amplify the signal being fed into its
input jacks. It's job is NOT to amplify the errors in the line
voltage.
--
| Dick Pierce |
| Professional Audio Development |
| 1-781/826-4953 Voice and FAX |
| DPi...@world.std.com |
chung
> "chung" <chun...@covad.net> wrote in message
> news:b6fdd...@enews1.newsguy.com...
>> David Power wrote:
>> Off-topic rant: For me, the best upgrade for that kind of money is to
>> buy a 20 inch LCD monitor. It gives you a much better outlook on
>> everything. I can't stand it when my audiophile friends spent big bucks
>> on cables and DAC's, and are squinting in front of that old 15 inch CRT
>> monitor where they spend more of their time. Rant finished.
>
> My Rant: All my audiophile friends don't even bother with 'squinting in
> front of that old 15 inch CRT' as they have high end stereo systems which
> they are mostly content with. They are not at all interested in TV, home
> cinema, surround sound, 5.1 or whatever you will. They feel as I do, we've
> seen the Hi Fi shows home cinema dems, Home Cinema Salons et al and are fed
> up with explosions, helicopter crashes 'impressive' but ultimately deadly
> boring displays. This has nothing at all to do with reproducing music
> faithfully, which is and always has been our aim. We don't want to even try
> to emulate a cinema complex in the home. In most complexes the sound is
> mostly and relentlessly overcompressed with overly 'impressive' (again read
> boring) sub activity. Rant finished.
You understand I was talking about computer monitors, that ones you use
to write your rants with?
>
> We have all installed dedicated mains because our systems all sound
> considerably better. No we haven't done it because of any tripping problems,
> grounding problems. The wide-band noise reduction came as a bonus as non of
> us had any perceivable hum problems except from occasional transfomer noise
> (which was eliminated by the upgrade) No we don't have any exact
> difference measurements ... it just sounds a lot better and all in all a
> very cost effective upgrade, far cheaper than a 'big bucks cable' - period.
>
Point duly noted. A lot of my friends have not upgraded AC service, and
are still very happy with their systems.
chung
> chung <chun...@covad.net> wrote in message
>
> Now any hi-fi
>> product that fails to regulate when the incoming line voltage fluctuates
>> by a couple of volts is not designed right.
>
> Your post was way over my head (my problem), so I have zeroed in on a
> sentence that I can understand. I have a series of closely related
> questions pertaining to "regulation".
>
> What are example of amps, especially lower cost amps, that regulate?
> Are they the exception or the rule? What are examples of amps that
> don't regulate? Is this a feature that is usually advertised? How is
> a consumer to know? Do some amps regulate better than others?
CD's, DAC's and preamps almost always have regulated power supplies,
except the ones that run off batteries, or passive preamps. That's why I
was asking whether hiss/hum was coming from preamp or power amp. You can
tell by disconnecting the preamp and see if the hiss is still there, and
also check whether hiss/hum depends on volume control settings.
Power amps' output stages run off high-voltage supplies. The amp's
output follow the input, except for the gain factor, because of
feedback, or because of a stable relationship between output and input.
Regulation in this case means the control of output voltage independent
of minor variations in supplies and in AC conditions. I would expect
power amps that use very little overall feedback to be more susceptible
to AC line conditions, as well as temperature and loading. The reason is
that without overall (global) feedback, the gain of the power amp is a
function of biasing which in turns depends on supply voltages,
temperature, device tolerances, etc. Also without global feedback, there
is a larger transfer function between power supply voltage and output
voltage. Feedback minimizes that transfer function, if implemented
correctly.
Supply filtering is always provided by the power supply sections of the
preamps or power amps. Those huge capacitors insure the output rails do
not change rapidly as a function of input signal level, or AC noise. The
absolute level of the high-voltage supplies may depend on the average
level of the incoming AC, but that only has an effect on maximum power
available to the speaker load, and not on noise level.
>
> If one owns an amp that he or she likes, but that amp does not
> regulate and there are known AC line issues, i.e. capacity issues,
> could it be a plausible solution, depending on cost, to install a
> dedicated circuit for you audio system?
I do not know of any competent amp that fails to work over the range of
line voltages normally encountered in homes. I am assuming you meant
power amps. If the in-rush currents cause the breakers to trip, then
yes, there is a capacity issue, and you can add a separate AC line to
add capacity.
>
> My amp, the Nuvista 300, has a "regulated choke supply", which may or
> may not have anything to do what we are talking about. This is a 110
> pound unit, of which 50 Lbs are devoted to the power supply (PSU) and
> "choke regulation". Based on what you know, is this an amp that
> regulates with respect to incoming line voltage fluctuations? By the
> way, I will not take offense to your response now that I have a little
> better understanding what you are talking about?
Your power amp, with its large power supply, may have a very large
in-rush current. That's the current needed to charge up the large filter
capacitors on the other side of the power transformer, from a discharged
state. The "choke regulation" I suspect is for RFI filtering, but I am
not sure. In other words, I think it prevents noise on the AC line to
pass on to the output voltage rails that the output stages run off. So,
it should regulate well against noise (from high-frequency switching
circuits, etc.). The large in-rush current can cause the AC line voltage
is sag momentarily, causing other components on that AC circuit to
experience "brown-outs", like lights dimming, receivers resetting, etc.
Once the power amp is turned on, its current requirements should be
fairly modest, unless you play it really loud.
If the power supply section is defective, like having leaky capacitors,
it is possible to experience poor regulation since the voltage rails are
not stable (fixed and clean).
When I read that you are experiencing higher background noise with old
wiring, my thinking process goes like this:
1. Is the hiss/hum coming from the power amp or the preamp, or both.
How can we isolate the problem?
2. Is the noise hum or hiss? Hum means line related problems most
often associated with AC ground loops. That is, the supply currents are
flowing through the wrong points in your sysem. Hiss can be due to some
form of RFI pickup by sensitive stages, or by poor regulation of
preamps/CD/DAC allowing noise on the power supply to feed through to the
outputs. It is not hard to measure these effects.
3. Why would a dedicated AC line fix the problem? Is it because the
culprit of RFI noise is now on a different circuit? Is it because the AC
line voltage is slightly higher (due to less loading)? Is it because
the physical rewiring of the system eliminated some other causes of noise?
I read that many people seem to benefit from new wiring. I am not saying
that what you are experiencing is not real. But it would really be
beneficial to everyone to be able to explain why. I am sure that once we
figure out why, we can agree that new wiring is not necessary to solve
audio problems, unless there is a capacity or safety or reliability issue.
>
> Finally, I employ a passive line stage (passive pre). Of course, there
> is no power supply, no regulation. How does a passive pre fit into the
> equation?
A passive preamp should be independent of AC conditions. Only thing to
worry about is ground loops.
>
> Robert C. Lang
Alan Hoyle
> (single ended amplifiers could well be EXTREMELY sensitive to simply
> line coltage variations)
In my experience, virtually all audio products are sensitive to even
minor "coltage" variations. It doesn't take a stampede of stallions
to affect most amplifiers, even a smallish pony can affect them very
easily. This does go a long way towards explaining the high mass of
some of the more expensive boutique models: they're more resistant to
"coltage" because their massive "heat sinks" are really armor plating.
Perhaps we engineering types have been looking for the wrong
explanations. How else would you design a horse-proof stereo system?
Light weight? Neigh, you want big masses of iron.
;-)
-alan
--
Alan Hoyle - al...@unc.edu - http://www.alanhoyle.com/
"I don't want the world, I just want your half." -TMBG
Get Horizontal, Play Ultimate.
Mike Gilmour
Your points 2) & 3) are very interesting because the most successful
'rewire' we've done was for an audiophile living a few miles from Kinloss
military airfield. Conscious of strong RFI hash we ensured all mains feeds
were screened from the supply to the equipment & also utilised ferrite rings
for good measure.
My thoughts are this, screened mains cable I assume would not be so good as
an RF feeder, if RF was present on the incoming would it not attenuate over
say 20M of screened SWA cable?
Large bipolar speakers may also act as aerials & allow RFI in via speaker
cables back into the amp . Now one of my power amps has (manufacturers)
figures of frequency response 0.4Hz to 1MHz -3db lots of scope for
amplifying RF hash to rob power & produce heat.
One other thing, the war has made his place a quieter place.
Robert Lang
> In article <b6hup...@enews3.newsguy.com>,
> Robert Lang <Rober...@msn.com> wrote:
> >My amp, the Nuvista 300, has a "regulated choke supply", which may or
> >may not have anything to do what we are talking about. This is a 110
> >pound unit, of which 50 Lbs are devoted to the power supply (PSU) and
> >"choke regulation". Based on what you know, is this an amp that
> >regulates with respect to incoming line voltage fluctuations?
>
> A "choke regulator" is not a regulator at all. It is simply a
> line ripple filter. The power supply output will be directly
> proportional to the AC voltage input. If the rest of the circuit
> has poor power supply rejection properties, an unfortunately
> all-to-common characteristic of a lot of high end stuff (single
> ended amplifiers could well be EXTREMELY sensitive to simply
> line coltage variations), then, indeed, there could be audible
> changes.
>
>
Is a "choke regulator" the same as "regulated choke suppy"? It seems
they could be vastly different. In any event, the manual makes it
clear that the "regulated choke supply" is just *one* aspect of this
very massive power supply, although the manual speaks in very general
terms. Itdoes seems to be more than "simply a line ripple filter"
(but it could be just that). I'm not so sure that it should be "type
cast" is this manner, without specific knowledge of this amplifier and
it topology. This is why I asked for comments based on specific
knowledge of *this* (NuVista 300) amplifier.
Robert C. Lang
chung
In the Musical Fidelity website, they say this about "Full Choke
Regulation":
***
Full choke regulation.
Incredibly clean power supply lines because any mains interference is
eliminated and, as a result, circuitry can operate at its optimum.
***
It is designed to withstand interferences on the AC lines (like all
components should be). I would expect the designers have tested this amp
with all sorts of noise/interference on the power lines. So why would a
dedicated AC line help?
The answer perhaps is that something else upstream in your system is
susceptible.
BEAR
> In article <b6hup...@enews3.newsguy.com>,
> Robert Lang <Rober...@msn.com> wrote:
> >My amp, the Nuvista 300, has a "regulated choke supply", which may or
> >may not have anything to do what we are talking about. This is a 110
> >pound unit, of which 50 Lbs are devoted to the power supply (PSU) and
> >"choke regulation". Based on what you know, is this an amp that
> >regulates with respect to incoming line voltage fluctuations?
>
> A "choke regulator" is not a regulator at all. It is simply a
> line ripple filter. The power supply output will be directly
> proportional to the AC voltage input. If the rest of the circuit
> has poor power supply rejection properties, an unfortunately
> all-to-common characteristic of a lot of high end stuff (single
> ended amplifiers could well be EXTREMELY sensitive to simply
> line coltage variations), then, indeed, there could be audible
> changes.
>
Mmmm...
Not being familiar with this particular product, I'd suspect that this is
not a *line* filter at all, but an "L" or "Pi" network filter on the B+ for
the amp... the "regulated choke" part, I am surmising, is actually a
"swinging choke" (choke with an air gap).
And, yes this will provide a good bit of control of the B+ voltage vs. rapid
AC line voltage changes...
>
> But this is an indictment of the failure to adequately design
> the amplifier, NOT "evidence" that the amplfier is more
> transparent.
>
> An amplifier is NOT SUPPOSED TO BE TRANSPARENT TO LINE VOLTAGE
> ISSUES! That's not it's job. Who on earth in their right mind
> would could make such a claim with a straight face? AN
> amplifier's job is to amplify the signal being fed into its
> input jacks. It's job is NOT to amplify the errors in the line
> voltage.
Calm down, Richard, calm... the job of the amplifier is to NOT amplify
variations in line voltage, yes? So, to that extent is *is* supposed to be
"TRANSPARENT TO LINE VOLTAGE ISSUES"!!
It all depends upon how you frame an issue or question as to what sort
of response you're likely to illicit... now back to my meditation...
_-_-bear
>
>
> --
> | Dick Pierce |
>
--
_-_-bearlabs
http://www.bearlabsUSA.com
- Silver Lightning Interconnects & Custom Mods -
chung
>
> Your points 2) & 3) are very interesting because the most successful
> 'rewire' we've done was for an audiophile living a few miles from Kinloss
> military airfield. Conscious of strong RFI hash we ensured all mains feeds
> were screened from the supply to the equipment & also utilised ferrite rings
> for good measure.
> My thoughts are this, screened mains cable I assume would not be so good as
> an RF feeder, if RF was present on the incoming would it not attenuate over
> say 20M of screened SWA cable?
I'm not familiar with the terms RF feeder and SWA cable. RF on the AC
mains is unlikely to get through the power supply section of audio
products. Ferrite rings aroung the power cords can help common-mode
rejection of conducted RF.
> Large bipolar speakers may also act as aerials & allow RFI in via speaker
> cables back into the amp .
I have never seen this happen. The output impedance of the amp should be
low enough to not let RF creep back into the amp circuits. Your speakers
should be terrible antennas.
> Now one of my power amps has (manufacturers)
> figures of frequency response 0.4Hz to 1MHz -3db lots of scope for
> amplifying RF hash to rob power & produce heat.
A 1MHz power amp is clearly an overkill. It should be straightforward to
measure the output spectrum at the output of the power amp to see if
noise is present. Try a more conventional power and compare.
Since we cannot hear RF, RF has to be rectified or somehow downconverted
before appearing as noise in the audio spectrum. I would be very careful
with shielding the interconnect cables, and the phono cables in particular.
chung
>
> The current system amps use a 2 stage turn on to help prevent major
> inrush surges. If the mains blip, I blow the breakers and several
> fuses because of the inrush.
What do you mean by "if the mains blip"? You shouldn't blow fuses
because of the inrush. What kind of fuses are these?
> I have 3- 750 tube watt amps, 5 subs w 300 watt amps 2- 450 watt tube
> amps, plus the front end gear and the rptv in that room. It does have
> a bit of inrush.
Who needs three 750 W tube amps and two 450 W tube amps? Your system is
not typical at all. I hope these are not Class-A amps. A 20 amp circuit
can only provide 2,300 watts continuously.
(snip)
>>>
>>> Monitoring the main dedicated line (12 gauge, which I had the amps
>>> plugged into) I could watch the current peak and the voltage drop as I
>>> played music at reasonable listening levels (my wife and I could have
>>> a conversation in the room at the time).
>>
>>What are the magnitudes of the drops?
>
> 10 to 12 volts max 3-5 normally, this is with a 200 mhz scope, a volt
> meter hardly shows a flicker.
Are you talking about a constant drop, or transients? A 10-12 V ringing
seems very high. How did you measure it exactly? Where do you clip the
ground lead to?
>
>>Now any hi-fi
>>product that fails to regulate when the incoming line voltage fluctuates
>>by a couple of volts is not designed right.
>
> Most amps don't regulate at all they just pile on caps which don't
> have much affect as far as I can tell on line voltage, just amperage
> drops.
Those caps regulate the output voltage rails against transient ringing
and other noise on the incoming AC lines. They do not regulate in the
sense that they provide fixed DC voltages level to the amp. Even if your
incoming AC drops by a couple of volts due to IR, (which is unlikely
considering the length of your run) the effect on the output of the
power amp should be minimal: you just lose a little bit of headroom.
(snip)
>
> I had the amps plugged into the dedicated circuit the front end was
> using the shared circuit.
Be wary of ground loops. Now the supply current has two different paths
of returning.
(snip)
>>So no appliances on that circuit I assume. What are the magnitudes of
>>the drops?
>
> The system except for lighting is all on dedicated circuits now, The
> voltage variation measured with the scope is now around 2 volts.But I
> do see the mains voltage vary by 6 to 8 volts based by time of day
> and day of the week .
That seems excessive to me.
(snip)
>
>>> I'm am planning an even more extensive power system in my new house
>>> for my music room and I'm interested in seeing what I end up with.
>>>
>>
>>Dare I say "expectation bias"?
>
> If my experiences are any indication its similar to the expectation of
> buying a v-8 vs a straight 4.
Buying, or driving? Is it possible that all of us are driving straight 4's?
>
> I'm also putting in a isolation transformer to supply "balanced power"
> to the circuits. All lines to the amps and subs are 10 gauge stranded.
> Ill be measuring these lines referenced to the standard mains as the
> construction progresses.
Does any of the amp manufacturers ever recommend their customers to go
to this extreme to get the best performance? Do you think that Krell, or
Bryston demand that their dealers do this for their lsitening rooms?
Mike Gilmour
news:b6n60...@enews4.newsguy.com...
> Mike Gilmour wrote:
> >
> > Your points 2) & 3) are very interesting because the most successful
> > 'rewire' we've done was for an audiophile living a few miles from
Kinloss
> > military airfield. Conscious of strong RFI hash we ensured all mains
feeds
> > were screened from the supply to the equipment & also utilised ferrite
rings
> > for good measure.
> > My thoughts are this, screened mains cable I assume would not be so good
as
> > an RF feeder, if RF was present on the incoming would it not attenuate
over
> > say 20M of screened SWA cable?
>
> I'm not familiar with the terms RF feeder and SWA cable. RF on the AC
> mains is unlikely to get through the power supply section of audio
> products. Ferrite rings aroung the power cords can help common-mode
> rejection of conducted RF.
SWA cable is Steel Wire Armour, close lapped steel wires to protect the
inner cables.This type of cable is often used buried in ground. (The armour
doubles nicely as screening).
I believe RF can be coupled through the mains because in every time we've
used screened mains supplies all the way back to the consumer unit there is
a marked drop in wide band noise.
>
> > Large bipolar speakers may also act as aerials & allow RFI in via
speaker
> > cables back into the amp .
>
> I have never seen this happen. The output impedance of the amp should be
> low enough to not let RF creep back into the amp circuits. Your speakers
> should be terrible antennas.
RF does not always behave as expected, I remember a time of keying a
transmitter on a particular 16 Mhz frequency which unfortunately also
produced induced RF that resonated strongly with my metal headphone band.
Ouch! (ok, no comments please)
There has been reports of ferrite rings actually reducing wideband noise
when used on speaker outputs, I haven't tried this myself so I can't confirm
it. That is why I was considering probable RF pickup.
>
> > Now one of my power amps has (manufacturers)
> > figures of frequency response 0.4Hz to 1MHz -3db lots of scope for
> > amplifying RF hash to rob power & produce heat.
>
> A 1MHz power amp is clearly an overkill. It should be straightforward to
> measure the output spectrum at the output of the power amp to see if
> noise is present. Try a more conventional power and compare.
I've had a scope on the output & it appears 'clean'.
> Since we cannot hear RF, RF has to be rectified or somehow downconverted
> before appearing as noise in the audio spectrum. I would be very careful
> with shielding the interconnect cables, and the phono cables in
particular.
>
RF can be rectified / demodulated by a bad 'diodic' connection i.e a dirty
connection between dissimilar metals - I've heard this before on poorly
wired phono inputs that give low level local radio (& often radio Moscow)
output to the speakers.
Definitely more is research needed into this phenomema as too many have
reported reductions in wideband noise through dedicated ac supplies.
David Power
>David Power wrote:
>
>>
>> The current system amps use a 2 stage turn on to help prevent major
>> inrush surges. If the mains blip, I blow the breakers and several
>> fuses because of the inrush.
>
>What do you mean by "if the mains blip"? You shouldn't blow fuses
>because of the inrush. What kind of fuses are these?
If the power flickers from the power company, it happens a lot
during thunderstorm season.
20 amp fast blow in the power strips. I'm now using unfused power
strips.
>> I have 3- 750 tube watt amps, 5 subs w 300 watt amps 2- 450 watt tube
>> amps, plus the front end gear and the rptv in that room. It does have
>> a bit of inrush.
>
>Who needs three 750 W tube amps and two 450 W tube amps? Your system is
>not typical at all. I hope these are not Class-A amps. A 20 amp circuit
>can only provide 2,300 watts continuously.
I do, they are the VTL mono blocks ( class ab) that power my music
room. The 750's are front right, left and center the 450's are rear
left and right. along with 4 powered Vandersteen 2q's and 1 2w sub
woofers.
Who's to say what's typical, I think a cheep sanyo receiver is
probably a lot closer to typical. This thread wasn't about typical
power, for that matter I don't think any one here is typical, they all
know about, and how to use Usenet.
My first big music system (much longer than I care to think about)
used Carver 700's in the fronts and 400 amps for the rear and used
four Speaker Lab/ Klipsh corner horn knock offs. Its changed on and
off over the years, 4 crown 300s lived here for a while as well as
different tube or solid state designs. I have run across a lot of
people that use similar systems. I was helping a friend run a new
power circuit to his 4 perraux 200 watt amps this weekend he also
uses a couple of 100 watt perrauxs to power other rooms.
I wont even begin with old PA systems that have been converted to home
systems that require 220v power distribution panels (its amazing what
your friends collect after owning a night club or two.)
I do like to be able to play very dynamic music at fairly high
volumes and like the effortless quality that a big amp has. Some
people drive a Mercedes or 8 watt set's .I buy big tube amps and drive
a 6 year old used caddie instead.
>(snip)
>>>>
>>>> Monitoring the main dedicated line (12 gauge, which I had the amps
>>>> plugged into) I could watch the current peak and the voltage drop as I
>>>> played music at reasonable listening levels (my wife and I could have
>>>> a conversation in the room at the time).
>>>
>>>What are the magnitudes of the drops?
>>
>> 10 to 12 volts max 3-5 normally, this is with a 200 mhz scope, a volt
>> meter hardly shows a flicker.
>
>Are you talking about a constant drop, or transients? A 10-12 V ringing
>seems very high. How did you measure it exactly? Where do you clip the
>ground lead to?
>
Transient drops, and mains sag, measured at the wall outlet. The
ground is clipped to the outlet ground or floating. I've also measured
ringing on the mains during loud passages. I also use a modified
current probe to measure peak current demands. The new circuits are
showing much greater peaks using the same equipment and material. I'm
assuming this is due to their greater ability to deliver current
without limiting.
Stick a scope on you outlet while the system is off, on and while
playing music. It can be quite interesting.
>>
>>>Now any hi-fi
>>>product that fails to regulate when the incoming line voltage fluctuates
>>>by a couple of volts is not designed right.
>>
>> Most amps don't regulate at all they just pile on caps which don't
>> have much affect as far as I can tell on line voltage, just amperage
>> drops.
>
>Those caps regulate the output voltage rails against transient ringing
>and other noise on the incoming AC lines. They do not regulate in the
>sense that they provide fixed DC voltages level to the amp. Even if your
>incoming AC drops by a couple of volts due to IR, (which is unlikely
>considering the length of your run) the effect on the output of the
>power amp should be minimal: you just lose a little bit of headroom.
>
I want that little bit of headroom. I think that missing headroom is
what makes most systems sound so flat. i've been to a few live
performances with a sound meter (closet binaural taper) and was
surprised at how low the peeks can be, I find most of the time a
system had to be turned up much louder to even come close to sounding
similar.
>>
>> I had the amps plugged into the dedicated circuit the front end was
>> using the shared circuit.
>
>Be wary of ground loops. Now the supply current has two different paths
>of returning.
Always. I have the outlets all wired using the same wire of the same
length pulled to the same ground and have a special cable I made to
check for voltage and current flows between the equipment.
That's why I'm putting in a sub panel with an isolation transformer
and rf filters in the new house.
>(snip)
>>>So no appliances on that circuit I assume. What are the magnitudes of
>>>the drops?
>>
>> The system except for lighting is all on dedicated circuits now, The
>> voltage variation measured with the scope is now around 2 volts.But I
>> do see the mains voltage vary by 6 to 8 volts based by time of day
>> and day of the week .
>
>That seems excessive to me.
>
Me too, perhaps you would speak to my power company they don't seem to
listen to me.
>>
>Does any of the amp manufacturers ever recommend their customers to go
>to this extreme to get the best performance? Do you think that Krell, or
>Bryston demand that their dealers do this for their lsitening rooms?
Probably not, my dealer has a very extensive power system designed
into their store.
They build cars that burn regular gas and sell select beef for those
that don't care what they drive or eat as well.
I don't see the television manufactures performing even a simple ISF
calibration on their 5k rptvs but it still needs to be done if you
want it to look right.
I think that if you are going to spend a couple for thousand dollars
on a system you would be well served to put it on its own line. Its an
inexpensive and worthwhile upgrade.
I would certainly do this before purchasing new power cords, a PS300
or Richard Gray power station or any number of other power enhancement
products on the market.
Of course all opinions are my own, YMMV
David Power
Katy, Texas
Robert Lang
> Robert Lang wrote:
> > chung <chun...@covad.net> wrote in message
> >
> > Now any hi-fi
> >> product that fails to regulate when the incoming line voltage fluctuates
> >> by a couple of volts is not designed right.
> >
> > Your post was way over my head (my problem), so I have zeroed in on a
> > sentence that I can understand. I have a series of closely related
> > questions pertaining to "regulation".
> >
> > What are example of amps, especially lower cost amps, that regulate?
> > Are they the exception or the rule? What are examples of amps that
> > don't regulate? Is this a feature that is usually advertised? How is
> > a consumer to know? Do some amps regulate better than others?
>
> CD's, DAC's and preamps almost always have regulated power supplies,
> except the ones that run off batteries, or passive preamps. That's why I
> was asking whether hiss/hum was coming from preamp or power amp. You can
> tell by disconnecting the preamp and see if the hiss is still there, and
> also check whether hiss/hum depends on volume control settings.
A good part of the difficulty in pinpointing the noise source is that
I made the change to a dedicated AC line more than 8 years ago. So
when I say I don't know, it is more accurate to say I don't remember.
Also, much of the gear that I was using then I am not using today. And
most importantly, since I was not looking for an improvement in the
noise level when I went to the dedicated circuit I really did not
bother to pinpoint the type of noise.
But one thing is clear, the noise could not come from the pre because
I was using a passive back then as I am today. That leaves the amps.
My primary amp (for the mains) at the time of my change to the
dedicated line was a Bedini 803, a Class A design. (I had and still
have Electron Kenetic 400 mono for the bass modules but they are not
really a factor with respect to noise, although come to think about it
they use to "hum" from the components themselves. This is no longer
the case). But could the problem have been my electronic crossover? I
definitely had a noise problem with it at one point when a level pot
went bad. I’m not sure if that problem was before or after the
switch to the dedicated line. One thing that was very clear was that
older circuit was far more susceptible to audibly higher noise than
the new one as evidenced by plugging the system, irrespective of
changes to the system, into both circuits.
Now with the current gear plugged into the dedicated line the hiss/hum
level is dependent on the volume setting. At the listening position,
with the system at idle and the volume control set for normal
listening levels (loud) there is virtually no audible noise; just a
smidgen which is undetectable during music. The noise is audible right
near the speaker and it is annoying if I crank the volume up all the
way. But the speakers are relatively efficient (92db) and I have gobs
of power into the 4 ohm load (more than 1000 watts). I would never
have the volume/power up anywhere near that level during listening
sessions.
>
I would expect
> power amps that use very little overall feedback to be more susceptible
> to AC line conditions, as well as temperature and loading. The reason is
> that without overall (global) feedback, the gain of the power amp is a
> function of biasing which in turns depends on supply voltages,
> temperature, device tolerances, etc. Also without global feedback, there
> is a larger transfer function between power supply voltage and output
> voltage. Feedback minimizes that transfer function, if implemented
Ø correctly.
In some ways could this be a design choice? I recall back in the 70s
and early 80s when high-end amps makers used gobs of feedback and
underscored that in their advertisement. In the 80s that almost turned
around completely when many makers began to openly eschew feedback
citing TIM and other side affects stemming from the employment of
feedback. The Nuvista 300 manual cites the use of "little overall
feedback" in the amp design.
>
>
> I do not know of any competent amp that fails to work over the range of
Ø > line voltages normally encountered in homes.
I assume that almost all, but not all amps are "competent amps". Do
you know of amps, especially, solid state amps, that are lacking in
this area, not competent? I’m asking you to name names. If you
don’t know, where/how can a consumer find out?
>
> When I read that you are experiencing higher background noise with old
> wiring, my thinking process goes like this:
>
Ø 1. Is the hiss/hum coming from the power amp or the preamp, or
both.
When I made the change to the dedicated line 8 years ago, I
don’t know where the noise was coming from, but since one
constant has been a passive pre that leaves the amps or possibly the
electronic crossover. In either case the noise is greater with the
older circuit. Plugging the system power strip into one or the other
clearly confirms the noise differences.
>
> 2. Is the noise hum or hiss? Hum means line related problems most
Ø often associated with AC ground loops.
Ø
With the newer circuit there is a tiny bit of both, although not
audible at the listening position and definitely not ever audible with
music. The noise is volume dependent. With the older circuit the noise
is also volume dependent. By comparison it is always a little noisy at
the listening position. Much of the time the noise was not that bad. I
got use to it. But at other times, probably when something like an
appliance turns on, hum is audible during music.
> 3. Why would a dedicated AC line fix the problem? Is it because the
> culprit of RFI noise is now on a different circuit? Is it because the AC
Ø line voltage is slightly higher (due to less loading)?
I would say that the answer could be either of these.
Ø Is it because
Ø the physical rewiring of the system eliminated some other causes of
noise?
This is not a factor. At the time of the initial installation of the
dedicated line there was no rewiring of the system. Likewise, having
made more recent comparisons of the two lines, by simply plugging the
system into one or the other there has been no rewiring.
we can agree that new wiring is not necessary to solve
Ø audio problems, unless there is a capacity or safety or reliability
issue.
That seems reasonable. But could fluorescent lighting or appliances
cause problems? In the past fluorescent lights has caused issues for
me (and many others), although I don’t know if they were the
root of the problem. But suppose there were some uncontrollable such
as a refrigerator, periodic hair dryer, fluorescent lights, etc., on
one circuit, that contributes, if not causes, noise problems? This may
very well speak to a capacity issue. But capacity issues (mild ones)
may be far more common that we realize, may be even the norm in older
homes when the original lines may have never anticipated a lot of
modern appliances, especially a thousand watts of amplification. But
capacity issues not withstanding, could a dedicated circuit be an
ideal, low cost, relatively painless solution, in these environments.
Speaking of capacity, sure the lights dimmed a bit (no big deal) when
I turned on the system before the new line was installed. But
that’s not what caused me to get a new line. It was another type
of capacity issue. I simply did not have enough receptacles in the
living room for both everyday household use and my sound system!
Robert C. Lang
Robert Lang
> In the Musical Fidelity website, they say this about "Full Choke
> Regulation":
> ***
> Full choke regulation.
> Incredibly clean power supply lines because any mains interference is
> eliminated and, as a result, circuitry can operate at its optimum.
> ***
>
> It is designed to withstand interferences on the AC lines (like all
> components should be). I would expect the designers have tested this amp
> with all sorts of noise/interference on the power lines. So why would a
> dedicated AC line help?
>
> The answer perhaps is that something else upstream in your system is
> susceptible.
I have shared with you my complete system. What do you think might be
susceptible? Keep in mind that the system is clearly, albeit
intermittently, more noisy when I plug it into the older circuit.
Robert C. Lang
Howard Ferstler
> On 5 Apr 2003 21:04:24 GMT, chung <chun...@covadnospam.net> wrote:
>
> >David Power wrote:
> >
> >>
> >> The current system amps use a 2 stage turn on to help prevent major
> >> inrush surges. If the mains blip, I blow the breakers and several
> >> fuses because of the inrush.
> >
> >What do you mean by "if the mains blip"? You shouldn't blow fuses
> >because of the inrush. What kind of fuses are these?
> If the power flickers from the power company, it happens a lot
> during thunderstorm season.
> 20 amp fast blow in the power strips. I'm now using unfused power
> strips.
Generally, when the going gets tough and big thunderstorms head my way
I unplug the power inputs to all three of my home A/V systems. I do
have surge protected power for all three, but I would never trust that
protection when when really rough weather threatens.
I am curious about four things:
1) How big is your listening room?
2) What speaker models are you using and what are their efficiencies?
3) How loud are your program peaks?
4) Have you measured the output of those amps of yours when achieving
those peaks?
I ask this, because I have been playing around with multi-channel
audio for some time (enough to write four books on A/V and record
reviewing) and I find it incredible that anyone would actually need
750 watts on each of the three front channels and even more incredible
that anyone would need 450 watts on each of the surround channels. We
are talking peak levels in the 110 to 115 dB, or even 120 dB range
with typical loudspeakers in most rooms. That is anything but those
"fairly high volumes" you noted, and are well above what would be
encountered at anything short of a heavy-metal rock concert. Heck, in
my own listening room I find 100 dB peaks to be disconcerting, and I
can reach levels that high with 50 wpc, given that I have a pair of
subwoofers to handle the low-bass range. I have considerably more
power than that, but I am willing to admit that this is overkill.
I see that your earlier system had Klipsch speakers and those are
normally very efficient. I find it hard to believe that you used even
a small fraction of the power available from those Carver and Crown
amps to drive them.
Howard Ferstler
Robert Lang
> not typical at all. I hope these are not Class-A amps. A 20 amp circuit
> can only provide 2,300 watts continuously.
>
I've shared the make up my system with you. I don't consider it
exotic. But it is certainly not typical (certainly none of the
component manufacturers think so), at least by most standards. I would
venture to say that, at minimum, the combination of components in my
system are unlike any other in the country. This will be even more so
once I complete the surround portion of my system which will include a
custom surround passive pre and three additional high powered amps.
Most key components in the system were/are "limited" in availability.
I bet many of us could make the same claim. My point is that the
system is not typical is probably not "atypical" for participants in
this forum. This coupled with the wildly varied electrical
environments that many of us have to plug into is probably why general
diagnosis of AC issues in this group may not fit as well as with the
"average" consumer.
Robert C. Lang
chung
>
>>What do you mean by "if the mains blip"? You shouldn't blow fuses
>>because of the inrush. What kind of fuses are these?
>
> If the power flickers from the power company, it happens a lot
> during thunderstorm season.
> 20 amp fast blow in the power strips. I'm now using unfused power
> strips.
Maybe you should invest in surge suppessors. High amperage ones.
>
>>> I have 3- 750 tube watt amps, 5 subs w 300 watt amps 2- 450 watt tube
>>> amps, plus the front end gear and the rptv in that room. It does have
>>> a bit of inrush.
>>
>>Who needs three 750 W tube amps and two 450 W tube amps? Your system is
>>not typical at all. I hope these are not Class-A amps. A 20 amp circuit
>>can only provide 2,300 watts continuously.
> I do, they are the VTL mono blocks ( class ab) that power my music
> room. The 750's are front right, left and center the 450's are rear
> left and right. along with 4 powered Vandersteen 2q's and 1 2w sub
> woofers.
>
> Who's to say what's typical, I think a cheep sanyo receiver is
> probably a lot closer to typical. This thread wasn't about typical
> power, for that matter I don't think any one here is typical, they all
> know about, and how to use Usenet.
I don't know of anyone with 5 300-W subwoofers in his living room. If
you really want to listen loud, you need more than a 20 amp cicruit it
seems. Does 750 mean 750 watts?
>>(snip)
>>>
You cannot leave the ground lead floating. You pick up all kinds of
extraneous signals. Best way is to use two scope probes, both grounded
to earth ground, and make a differential measurement between hot and
neutral. I doubt very much if you really have 10-12V transients on your
power line.
>>>>Now any hi-fi
>>>>product that fails to regulate when the incoming line voltage
fluctuates
>>>>by a couple of volts is not designed right.
>>>
>>> Most amps don't regulate at all they just pile on caps which don't
>>> have much affect as far as I can tell on line voltage, just amperage
>>> drops.
>>
>>Those caps regulate the output voltage rails against transient ringing
>>and other noise on the incoming AC lines. They do not regulate in the
>>sense that they provide fixed DC voltages level to the amp. Even if your
>>incoming AC drops by a couple of volts due to IR, (which is unlikely
>>considering the length of your run) the effect on the output of the
>>power amp should be minimal: you just lose a little bit of headroom.
>>
> I want that little bit of headroom. I think that missing headroom is
> what makes most systems sound so flat. i've been to a few live
> performances with a sound meter (closet binaural taper) and was
> surprised at how low the peeks can be, I find most of the time a
> system had to be turned up much louder to even come close to sounding
> similar.
>
If you do the math, you'll see that there is not much power reduction
when your line voltage drops by a couple of volts.
>>>
>>> I had the amps plugged into the dedicated circuit the front end was
>>> using the shared circuit.
>>
>>Be wary of ground loops. Now the supply current has two different paths
>>of returning.
> Always. I have the outlets all wired using the same wire of the same
> length pulled to the same ground and have a special cable I made to
> check for voltage and current flows between the equipment.
> That's why I'm putting in a sub panel with an isolation transformer
> and rf filters in the new house.
>
>>(snip)
>>>>So no appliances on that circuit I assume. What are the magnitudes of
>>>>the drops?
>>>
>>> The system except for lighting is all on dedicated circuits now, The
>>> voltage variation measured with the scope is now around 2 volts.But I
>>> do see the mains voltage vary by 6 to 8 volts based by time of day
>>> and day of the week .
>>
>>That seems excessive to me.
>>
> Me too, perhaps you would speak to my power company they don't seem to
> listen to me.
A new AC circuit will not fix that.
>>>
>>Does any of the amp manufacturers ever recommend their customers to go
>>to this extreme to get the best performance? Do you think that Krell, or
>>Bryston demand that their dealers do this for their lsitening rooms?
> Probably not, my dealer has a very extensive power system designed
> into their store.
>
> They build cars that burn regular gas and sell select beef for those
> that don't care what they drive or eat as well.
> I don't see the television manufactures performing even a simple ISF
> calibration on their 5k rptvs but it still needs to be done if you
> want it to look right.
> I think that if you are going to spend a couple for thousand dollars
> on a system you would be well served to put it on its own line. Its an
> inexpensive and worthwhile upgrade.
My advice is to find out if there is a need to upgrade power first,
instead of just doing it and hoping that the system will then sound
better. It did not, in my case.
David Power
wrote:
>David Power <dpo...@hal-pc.org> wrote in message news:<im4ka.393146$sf5.7...@rwcrnsc52.ops.asp.att.net>...
>> On 5 Apr 2003 21:04:24 GMT, chung <chun...@covadnospam.net> wrote:
>>
>> >David Power wrote:
I'm going to try to clean this up a little as its getting cluttered.
Perhaps we need to start another thread as this is straying from the
dedicated AC line topic and is turning into a "Why the hell would you
do that" topic
>> >>
>Generally, when the going gets tough and big thunderstorms head my way
>I unplug the power inputs to all three of my home A/V systems. I do
>have surge protected power for all three, but I would never trust that
>protection when when really rough weather threatens.
I also try to unplug but some times that doesn't happen or the mains
drop without warning (this happened three times today).
>
>I am curious about four things:
>
>1) How big is your listening room?
That's hard to described in this house, it has an open central area so
both ends of the room are open to other large spaces and there are two
hallways that lead to other portions of the house. The main room area
is 18 x30 with a 10x 20 sun room and a 12x15 kitchen attached with
only low 3-4 ft wall separating them, the ceiling is a 10ft cathedral
with different ceiling trays in each area.
>2) What speaker models are you using and what are their efficiencies?
Magnepan 20.1 front right and left (85db), Magnepan 3.6 rear right and
left (85db), Magnepan MGCC1 for center channel duty (85db restricted
to 160hz). I also have some MG12s (using vtl tiny triode amps) that
pull rear channel duty on occasion and a spare 3.6 that I use as a
center channel depending on how I have the room setup and what I'm
playing with at that time.
>3) How loud are your program peaks?
110db using an analog radio shack meter on c weighted fast setting. I
do like to get loud on occasion but its usually very fast transients.
>4) Have you measured the output of those amps of yours when achieving
>those peaks?
No I haven't tried that yet, It hasn't been a concern up to this
point.
>I ask this, because I have been playing around with multi-channel
>audio for some time (enough to write four books on A/V and record
>reviewing) and I find it incredible that anyone would actually need
>750 watts on each of the three front channels and even more incredible
>that anyone would need 450 watts on each of the surround channels. We
>are talking peak levels in the 110 to 115 dB, or even 120 dB range
>with typical loudspeakers in most rooms. That is anything but those
>"fairly high volumes" you noted, and are well above what would be
>encountered at anything short of a heavy-metal rock concert. Heck, in
>my own listening room I find 100 dB peaks to be disconcerting, and I
>can reach levels that high with 50 wpc, given that I have a pair of
>subwoofers to handle the low-bass range. I have considerably more
>power than that, but I am willing to admit that this is overkill.
The magneplaners are not the most efficient speakers around by any
means but I do like the way that they sound.
Even with fairly large 200-300 watt amps I would notice a collapse of
the sound stage and the high end would get strident when pushed and
the amps would get warm or even shut down driving the low resistance
that they present.
I found that I really liked the combination of the vtl 750's and the
20.1s.
When I added a center channel I tried several different options
including suspending a 3.6 sideways over my rptv. I did find that
having an amp with the same signature as the mains was necessary to
fully blend the center to the mains so it is an overkill application
but does help fully merger character of the mains to the center and
keep the overall sonic character of the system balanced. I probably
could have used a 450 as the sonic signature is very close to the 750.
I am using the 450s in the rear for the same reason, the sonic
signature is very close to the main amps as is the timber of the
speakers.
I have run across several different types of surround recording, some
of which have the same, or very close to the same content in the rears
as the mains with quite dynamic content ( which sometimes require a
bit of rewiring to listen to) at this point who is to say where
surround is going to end up.
The idea is to have all 4 quadrants be as close as reasonably (or by
the comments in this thread)unreasonably possible.
I found that the planers mad a slapping sound if pushed so I added the
vandersteen subs. I like the way that they integrate into the system
and find that they work very well with the magneplaners. Rolling the
lowest frequencies to the subs helps keep the mains from compressing
the peaks.
I never claimed that this wasn't overkill and I find it incredible
that some people use 8 watt set's ,on the other hand it does bring
tears to my wife's eyes while playing the Eagles "When hell freezes
over" DVD and she doesn't complain about 4 very large speakers in our
room anymore.
I use a set of Vandersteen 3A sig with a Vcc5 center and vsm sigs for
my second system and I'm still trying to work out the amplification
setup. I want this to be a "flick one switch and it works" type setup
for my family to use,any recommendations would be appreciated.
>I see that your earlier system had Klipsch speakers and those are
>normally very efficient. I find it hard to believe that you used even
>a small fraction of the power available from those Carver and Crown
>amps to drive them.
That was long a go and far away, life was certainly different then.
The parties we threw could be heard for a long ways away, we always
invited all the neighbors so we got very few complaints (if we missed
some one they usually showed up just to see what was going on).
On several occasions the fuses got blown because things got turned up
a wee bit loud.
Now you will hear similar goings on with the younger crowd but the
sound is usually pretty bad, they don't seem care about much about the
systems or the sonics, but when you have been listening to 64k mp3's
do you really care about the sound anyway.
But hey its only rock and roll right?
>Howard Ferstler
David Power
Nousaine
I have three audioworkstations one of which uses a Crown Macro-Tech 5000VZ
which will produce 6000 watts into 4 ohms on a 100 volt ac line in either
bridged or parallel mono modes. I use this unit on a 115 volt ac line to test
car audio subwoofers and have never tripped a house breaker even when frying
really tough long stroke woofers making 130 dB SPL in the car.
I used this amplifier to test maximal output of my Home Subwoofer system (more
than 120 db SPL in-room @ 2 meters <10% distortion from 12 to 62 Hz) and found
that I wasn't able to drive the 8 TC Sounds long stroke 15-inch woofers to full
output at 10-12 Hz because I was afraid that my windows were going to pop from
thier frames. All on a 115 volt ac line with a 15 amp breaker never tripped
during testing.
I do have 2 separate 220 lines (stove, and sauna ... which will heat the 5
person box to 220 F if you're not careful. I usually like about 90 C. But my
audio systems don't seem to need one. Although I suspect I'll eventually find a
woofer that might require one for max output testing. If that happens I'll put
one in right away but, for now, standard ac circuits seem perfectly adequate.
>
>I see that your earlier system had Klipsch speakers and those are
>normally very efficient. I find it hard to believe that you used even
>a small fraction of the power available from those Carver and Crown
>amps to drive them.
>
>Howard Ferstler
Generally speaking, pun intended, separate audio circuits are a perfectly
legitimate audio accessory but will not be 'needed' in even the most
sophisticated systems. Actually I think a dedicated line for audio system,
projector and lighting with its own wall switch would be a great convenience.
David Power
> > If the power flickers from the power company, it happens a lot
> > during thunderstorm season.
> > 20 amp fast blow in the power strips. I'm now using unfused power
> > strips.
>
>Maybe you should invest in surge suppessors. High amperage ones.
I have a whole house suppressor as well as suppressors on the sub
panels.
> >
>
>I don't know of anyone with 5 300-W subwoofers in his living room. If
>you really want to listen loud, you need more than a 20 amp cicruit it
>seems. Does 750 mean 750 watts?
>
I have seen several setups that use 18 " or larger drivers in a box
large enough to put a refrigerator in. This takes up much less space.
I know of quite a few people that use three, so what's a couple of
more just for fun.
I agree on the more than one dedicated 20 amp circuit but isn't that
what this whole thread started out as?
Yes the VTL 750 is a 750 watt mono block
http://www.vtl.com/pages/mb750specifications.html .
It can be run (as I frequently do) in a 300watt triode mode. The subs
allow me to roll off everything that's feeding the mains and surrounds
so the panels don't flap if there is a sudden "burst" of sound.
Magneplaners can get quite ugly sounding if the mylar hits the
magnetic structure.
>You cannot leave the ground lead floating. You pick up all kinds of
>extraneous signals. Best way is to use two scope probes, both grounded
>to earth ground, and make a differential measurement between hot and
>neutral. I doubt very much if you really have 10-12V transients on your
>power line.
>
I've used the differential setup as well as the single ended floating
and grounded. I use different setups depending on what i'm trying to
isolate and monitor.
I believe that the whole reason that this tread has persisted is
because you doubt most everything that's been stated in this thread.
> >>
>If you do the math, you'll see that there is not much power reduction
>when your line voltage drops by a couple of volts.
>
But the math doesn't tell me why it sounds better, it does show that
it should be little better but I find its more than a little.
>
>A new AC circuit will not fix that.
>
Nope I agree, but you just said it seemed excessive, I'm just trying
to optimize what I have to work with.
>
>My advice is to find out if there is a need to upgrade power first,
>instead of just doing it and hoping that the system will then sound
>better. It did not, in my case.
>
And it did in mine
David
chung
> On 7 Apr 2003 21:45:26 GMT, chung <chun...@covadnospam.net> wrote:
>
>> > If the power flickers from the power company, it happens a lot
>> > during thunderstorm season.
>> > 20 amp fast blow in the power strips. I'm now using unfused power
>> > strips.
>>
>>Maybe you should invest in surge suppessors. High amperage ones.
> I have a whole house suppressor as well as suppressors on the sub
> panels.
>> >
>>
>>I don't know of anyone with 5 300-W subwoofers in his living room. If
>>you really want to listen loud, you need more than a 20 amp cicruit it
>>seems. Does 750 mean 750 watts?
>>
> I have seen several setups that use 18 " or larger drivers in a box
> large enough to put a refrigerator in. This takes up much less space.
> I know of quite a few people that use three, so what's a couple of
> more just for fun.
>
> I agree on the more than one dedicated 20 amp circuit but isn't that
> what this whole thread started out as?
No, if you need more than 20 amps, then surely the standard 15 amp
circuit will not suffice. I think we all agree that if you run out of
capacity, then you should upgrade. The question is whether any upgrade
will improve performance.
>
> Yes the VTL 750 is a 750 watt mono block
> http://www.vtl.com/pages/mb750specifications.html .
> It can be run (as I frequently do) in a 300watt triode mode. The subs
> allow me to roll off everything that's feeding the mains and surrounds
> so the panels don't flap if there is a sudden "burst" of sound.
> Magneplaners can get quite ugly sounding if the mylar hits the
> magnetic structure.
>
>>You cannot leave the ground lead floating. You pick up all kinds of
>>extraneous signals. Best way is to use two scope probes, both grounded
>>to earth ground, and make a differential measurement between hot and
>>neutral. I doubt very much if you really have 10-12V transients on your
>>power line.
>>
> I've used the differential setup as well as the single ended floating
> and grounded. I use different setups depending on what i'm trying to
> isolate and monitor.
>
> I believe that the whole reason that this tread has persisted is
> because you doubt most everything that's been stated in this thread.
>
>> >>
I thought the reason it persisted is that there is some curiosity in the
subject, and there are unanswered questions.
>>If you do the math, you'll see that there is not much power reduction
>>when your line voltage drops by a couple of volts.
>>
> But the math doesn't tell me why it sounds better, it does show that
> it should be little better but I find its more than a little.
>>
If instead of 750 W, you get only 710 W max. Is it going to sound better?
>>A new AC circuit will not fix that.
>>
> Nope I agree, but you just said it seemed excessive, I'm just trying
> to optimize what I have to work with.
Your situation is unusual, so I'm not sure if recommending an upgrade
based on what your experiences is meaningful. Perhaps you should qualify
your strong recommendations?
Mark Wilkinson
Neat rig David! I'm going to try and give support to your "Why the hell
would you do that" topic.
> >2) What speaker models are you using and what are their efficiencies?
>
> Magnepan 20.1 front right and left (85db), Magnepan 3.6 rear right and
> left (85db), Magnepan MGCC1 for center channel duty (85db restricted
> to 160hz). I also have some MG12s (using vtl tiny triode amps) that
> pull rear channel duty on occasion and a spare 3.6 that I use as a
> center channel depending on how I have the room setup and what I'm
> playing with at that time.
>
> >3) How loud are your program peaks?
> 110db using an analog radio shack meter on c weighted fast setting. I
> do like to get loud on occasion but its usually very fast transients.
>
Let's run some numbers. The VTLs put out 750w continuous. Let's keep
everything real simple and arbitrarily give the VTLs 3-6db of peak
headroom -- lets say they can hit 2000w peaks, or roughly 2 to the 11th
power vs 1w. So that will give us 33 db (11x3db for each doubling of power)
of volume over 1 watt, for handling peaks. The speakers spec at 85db 1w/1m,
so at 1m we could expect to get 85 + 33, or 118 db peaks.
Now, let's see what that implies for real listening levels. I find that I
usually get about a 10db reduction at the listening position in a room of
any size vs 1m specs. So now we are down to 108 db peaks, which ties rather
closely to what David is measuring. But, that's peak and we need to adjust
down to average or slow readings. I typically read about 15 db difference
in a true peak reading meter vs ansi slow (1000ms exponential decay, time
averaged). So whack 15 db from from our 108 db peaks at listening position
and we are down to 93 db average volume at listening position with unclipped
peaks.
Not exactly blaring, is it? Whether the numbers are spot on or not, there
is no way you'ld assume this fantastic system, with monster 750w amps, to be
capable of a clean unclipped average 100db output. Kinda startling. You
really do need the power.
Back to why do it. I'm VERY much in David's camp of needing the headroom.
The above numbers show the average power or volume that a system can hit is
almost always limited by the unclipped peaks it can achieve. My bet is the
vast majority of all home systems are clipping peaks when driven to average
levels in the 90+db range at listening position.
Also, most home sytems aren't linear when pushed -- the bottom end usually
can't keep up with mid/highs. This is usually a problem with both the
speakers and their driving amps.
But people will say who listens to music that loud anyway -- it hurts. Yea
it does, when it's distorted. But take away away the distortion, get rid of
the clipping and the rise in harmonics,and all of a sudden it doesn't seem
too loud at all. In fact it often, depending on the type of music, sounds
MUCH more realistic/pleasing.
Also, when the low end doesn't keep up with the rest of the system,
percieved loudness INCREASES unpleasantly. I'm often surprised at how
turning up the power to a subwoofer, without touching any other volume
control, often provides relief from sound perceived to be overly loud.
Those of you who can should experiment with this, it's kinda cool.
Anyway, for those who will still say who the heck needs all that volume --
all I can say is you really ought to hear how allot of today's (even
yesterday's) rock/country /pop comes alive with enough volume, enough
headroom, and enough bass. Mark
Howard Ferstler
> On 7 Apr 2003 21:45:26 GMT, chung <chun...@covadnospam.net> wrote:
> >I don't know of anyone with 5 300-W subwoofers in his living room. If
> >you really want to listen loud, you need more than a 20 amp cicruit it
> >seems. Does 750 mean 750 watts?
> I have seen several setups that use 18 " or larger drivers in a box
> large enough to put a refrigerator in. This takes up much less space.
> I know of quite a few people that use three, so what's a couple of
> more just for fun.
A "couple of more" is money out of pocket for subwoofers that
otherwise might be used to purchase more recordings. "Fun" is
pointless if it does not gain you any real advantages.
Howard Ferstler
Nousaine
...snipped to pinpoint a given idea....
>Also, most home sytems aren't linear when pushed -- the bottom end usually
>can't keep up with mid/highs. This is usually a problem with both the
>speakers and their driving amps.
Dynamic spectral shift is a major problem with many home systems. It's exactly
as described ..... at loudnes increases the system will start to shreik at you.
Often this is not completely solved with the addition of a good subwoofer.
Often the addition of help at 60 Hz and below doesn't eliminate the mid-upper
bass compression that can occur. By this I mean that the low-lows can be
adequate but the mains may not have adequate capacity in the 60-120 Hz range so
you get an acoustic low-mid smiley face response at louder levels.
I had to add a mid-bass woofer in my system to ameliorate this mid-bass
compression problem when I built my 12 Hz subwoofer system because my active
twin 6.5-inch woofer mains couldn't keep up at 60-120 Hz with the subwoofer
when the gain was turned up.
>
>But people will say who listens to music that loud anyway -- it hurts. Yea
>it does, when it's distorted. But take away away the distortion, get rid of
>the clipping and the rise in harmonics,and all of a sudden it doesn't seem
>too loud at all. In fact it often, depending on the type of music, sounds
>MUCH more realistic/pleasing.
>
>Also, when the low end doesn't keep up with the rest of the system,
>percieved loudness INCREASES unpleasantly. I'm often surprised at how
>turning up the power to a subwoofer, without touching any other volume
>control, often provides relief from sound perceived to be overly loud.
>Those of you who can should experiment with this, it's kinda cool.
This is what I call the Dahlquist Effect. DQ-10s would sound pretty good at
moderate levels but at high volume the 10-inch woofer would max out and the rst
of the system would start screeching at you. The piss-ant Dahlquist
'subwoofer' didnt help much because it didn't have much bass either. A real
subwoofer with lots of overlap (60 Hz and above) with the DQ-10s was a good
answer.
>
>Anyway, for those who will still say who the heck needs all that volume --
>all I can say is you really ought to hear how allot of today's (even
>yesterday's) rock/country /pop comes alive with enough volume, enough
>headroom, and enough bass. Mark
Agreed; 120 dB at 1 kHz is painful but at 12 Hz it's quite comfortable and
satisfying. Check out those equal loudness curves.
David Power
True, I just purchased over 70 lps ( rca ,deutsche gramophones
,london FFrrr) most in unplayed condition from our local libraries
annual book sale for .50 to one dollar.
I have attending these for several years now and have amassed over a
thousand lps for much less then the cost of one sub. The operas all
contained the librettos and most of the records had been sleeved, many
years ago, in good rice paper thanks to our librarians of years past.
Getting good content is almost insignificantly cheep these days if you
are willing to do the vinyl thing unless 1/2 speed masters or the new
acoustic sounds 45 rpm series is what your after. Its going to take me
at least a year to listen to every thing I bought in two hours and I
haven't finished what I got last year.
I was crushed to find over 100 78's that would have been in mint
condition except for the fact that someone at the sale had dropped the
box and broke the bottom edge off of all the records in the box. I
probably should have bought them just to save the rest of the music on
the disks from being destroyed.
But of course"Fun" is why I turn the system on at all.
David
David Power
>
>Neat rig David! I'm going to try and give support to your "Why the hell
>would you do that" topic.
>
>everything real simple and arbitrarily give the VTLs 3-6db of peak
>headroom -- lets say they can hit 2000w peaks, or roughly 2 to the 11th
>power vs 1w. So that will give us 33 db (11x3db for each doubling of power)
>of volume over 1 watt, for handling peaks. The speakers spec at 85db 1w/1m,
>so at 1m we could expect to get 85 + 33, or 118 db peaks.
tubes in the amps.. I don't think the magnaplaners will get that loud
no matter how much power you push at them, they start to reach a
maximum excursion before that, I've noticed that after a while you
have to turn them up a lot more before they get detectably louder and
even then you reach a max where more power doesn't increase the sound
and I know the heat is building up somewhere.
>Now, let's see what that implies for real listening levels. I find that I
>usually get about a 10db reduction at the listening position in a room of
>any size vs 1m specs. So now we are down to 108 db peaks, which ties rather
>closely to what David is measuring. But, that's peak and we need to adjust
>down to average or slow readings. I typically read about 15 db difference
>in a true peak reading meter vs ansi slow (1000ms exponential decay, time
>averaged). So whack 15 db from from our 108 db peaks at listening position
>and we are down to 93 db average volume at listening position with unclipped
>peaks.
I find the system doesn't blare at all if I don't get out of hand.
>Not exactly blaring, is it? Whether the numbers are spot on or not, there
>is no way you'ld assume this fantastic system, with monster 750w amps, to be
>capable of a clean unclipped average 100db output. Kinda startling. You
>really do need the power.
>
>Back to why do it. I'm VERY much in David's camp of needing the headroom.
>The above numbers show the average power or volume that a system can hit is
>almost always limited by the unclipped peaks it can achieve. My bet is the
>vast majority of all home systems are clipping peaks when driven to average
>levels in the 90+db range at listening position.
One thing that we have noticed is that with the music very loud, you
can carry on a reasonable conversation at the same time. I believe its
because of the preservation of the dynamics of the music. There is
still plenty of quiet left to leave room for our voices to travel.
>Also, most home sytems aren't linear when pushed -- the bottom end usually
>can't keep up with mid/highs. This is usually a problem with both the
>speakers and their driving amps.
One of the reasons I have added subs in each corner, the bass is
outstanding at lower listening levels but if I turn it up loud it was
all horns and guitars, the bass and drums fall behind.
>But people will say who listens to music that loud anyway -- it hurts. Yea
>it does, when it's distorted. But take away away the distortion, get rid of
>the clipping and the rise in harmonics,and all of a sudden it doesn't seem
>too loud at all. In fact it often, depending on the type of music, sounds
>MUCH more realistic/pleasing.
So far , no matter how loud I listen to it, my ears never ring or get
overloaded, something I cant say about almost all the live shows I go
to. Lately most are not even intelligible but are not extremely loud.
Just so compressed that everything is at a flat scream level.
>Also, when the low end doesn't keep up with the rest of the system,
>percieved loudness INCREASES unpleasantly. I'm often surprised at how
>turning up the power to a subwoofer, without touching any other volume
>control, often provides relief from sound perceived to be overly loud.
>Those of you who can should experiment with this, it's kinda cool.
I do find I have to adjust the levels or "Q" of the subs from time to
time but have found a nice compromise. Adding the 5 th sub for the
effects channel allowed me to choose a slower sub with huge low bass
capability for unnatural events and still keep the system musical.
>Anyway, for those who will still say who the heck needs all that volume --
>all I can say is you really ought to hear how allot of today's (even
>yesterday's) rock/country /pop comes alive with enough volume, enough
>headroom, and enough bass.
>Mark
I would have to agree completely
Even some small three piece music looses the "blat" of the trumpet if
the system isn't dynamic enough.
Shall we move on....
David
Mark Wilkinson
major problem with many home systems. It's exactly
> as described ..... at loudnes increases the system will start to shreik at
you.
>
> Often this is not completely solved with the addition of a good subwoofer.
> Often the addition of help at 60 Hz and below doesn't eliminate the
mid-upper
> bass compression that can occur. By this I mean that the low-lows can be
> adequate but the mains may not have adequate capacity in the 60-120 Hz
range so
> you get an acoustic low-mid smiley face response at louder levels.
>
> I had to add a mid-bass woofer in my system to ameliorate this mid-bass
> compression problem when I built my 12 Hz subwoofer system because my
active
> twin 6.5-inch woofer mains couldn't keep up at 60-120 Hz with the
subwoofer
> when the gain was turned up.
>
Yep. Like you, I'm anticipating having to bolster the mid bass, albeit in
the 100-200hz range, when i add the next batch of subs.
>
> Agreed; 120 dB at 1 kHz is painful but at 12 Hz it's quite comfortable and
> satisfying. Check out those equal loudness curves.
Lucky you, I wouldn't know. Mid 20 hz is all I can reach with authority --
really start rolling off bad at 30.
The equal loudness curves are really very telling; it's always surprising to
see how fast weighted spl goes up on a meter when you crank the bass,
without it sounding like you cranked the volume eqiivalent to the increase
in meter readings. Hope that made sense. mark
>