speakers 'pop' on power up
HUM william
amp is turned on. I always thought that this was normal, but then I noticed
my uncle's system didn't do it. The 'pop' lasts for about a split second.
Also, when I power down, as the LED on my power amp slowly fades, this weird
'sound' (almost like something you hear in a sci-fi movie - ie. it's not
just a pop or crackle, but a tone which changes in frequency and is pretty
high pitched) comes out of both speakers. I've never heard this on any
other systems also. I might be worried over nothing but I am relatively
new to semi-hi-end-audio and bought my amp and power amp used, so I can't
say for sure if the gear is in perfect shape.
Power amp : Adcom GFA 545
Pre-amp : Adcom GFP 555
Speakers : 3a mm bi-wired with AudioQuest Indigo Blue. 10ft each side
My own theory (based on no scientific theory) is that my speakers are rated
at 91db sensitivity whereas my uncles are 89db. Could it be my speakers are
just more sensitive to the residual 'junk' being drained from my power amp?
(although it sounds almost like music and scared the hell out of me the first
time I heard it- lasts for about 1.5 seconds.)
Thanks in advance.
Will.
lenahan,grant f
> I would like to ask if it is normal for my speakers to 'pop' when my power
> amp is turned on.
Often, this is the circuitry stabilising, and the initial DC
produced. Some amps, like your uncle's, have a relay to mute this.
If its not too loud, don't worry. If it is, worry.
> Also, when I power down, as the LED on my power amp slowly fades, this weird
> 'sound' (almost like something you hear in a sci-fi movie - ie. it's not
> just a pop or crackle, but a tone which changes in frequency and is pretty
> high pitched) comes out of both speakers.
The "fade" is the power supply de-charging. No problem. The
"sound" is one I've encountered. Appears to be from the PS filter
caps - and may go away with time. Again, if its not loud enough to
damage your speakers, don't worry.
Both of these are artifacts of turn on / off in an amp without
a muting relay. Since I hate relays (sound / reliability), I'm
not concerned with the design.
Grant
Randall Elton Ding
>I would like to ask if it is normal for my speakers to 'pop' when my power
>amp is turned on.
>
>Pre-amp : Adcom GFP 555
>Speakers : 3a mm bi-wired with AudioQuest Indigo Blue. 10ft each side
>
have a mute relay. However they do have a bias delay circuit and
AC input surge suppressor relay. The pop you hear is generated by the
surge suppressor relay energizing (on my amps this happens 0.5 seconds
after the power is turned on, could be less on yours). This relay shorts
out a large resistor bank which is initially in series with the power
transformer, slowing down then inrush if current when the filter caps
are completely discharged.
I have a pair of GFA-565 mono amps and they do the same thing. It has
never been a problem for my speakers, although it is a little annoying.
Just for experimentation, I connected a portable KW hr meter (like the one
outside your home) to my amps. On power up, even with the surge supressor
circuit, that metal dial whips around so fast you'd think it was going to
come thru the glass. My TV, which is not even on the same circuit, looses
it's picture momentarily when I turn my two amps on together. So I figure
a standard 15A circuit may blow without such a suppressor circuit.
Randy
Craig Stark
What you describe has nothing to do with speaker sensitivity. In
fact, you could hook a dummy load up to the amp and watch the "pop" on
an oscilloscope. All it means is that your amp doesn't have a relay
or some such other device that cuts the output to the speakers off at
turn on and turn off. Apart from the jarring and startling effect the
pop and whine will have on you, there's not much to worry about. I
would refrain from playing music during power down, however, unless
there is some real need to drain the amps capacitors quickly. When
draining, the voltage on the rails will be dropping and it is easy to
send heavily distorted and clipped output to the speakers. Clipped
waveforms are the notorious killers of many a tweeter.
Craig Stark
Cal Lott
>In article <1ffq9n...@uwm.edu> h...@cs.concordia.ca (HUM william) writes:
>>I would like to ask if it is normal for my speakers to 'pop' when my power
>>amp is turned on.
>>
>>Power amp : Adcom GFA 545
>>Pre-amp : Adcom GFP 555
>>Speakers : 3a mm bi-wired with AudioQuest Indigo Blue. 10ft each side
>>
>Will, there is nothing wrong with your system. Adcom amps do not
>have a mute relay. However they do have a bias delay circuit and
[detailed description deleted]
>I have a pair of GFA-565 mono amps and they do the same thing. It has
>Randy
So how do you guys like your Adcoms? Everybody that I know has loved
theirs, and I am planning to purchase a GFA-545II in the future.
Can anybody name an amplifier line that they feel provides a better
price/performance ratio? I have heard a 100 watt amplifier from Aragorn
(sorry, but I can't recall the model designation) that was *sweet*, but
more than twice as expensive as the Adcom at about $800-900. I don't know
if the Aragorn is as robust as the Adcom when driving low-resistance
loads, either.
All of the low-end Carvers that I have heard sounded shrill and
really wimpy on the low end. They had a very open sound stage, however.
All in all, I'm pretty well sold on Adcoms.
-Cal
--
----------------------------------------------------------------------
Cal Lott "Oh, I see-- I though 'no' meant 'spoon'!" --Dan
Email me, baby! c...@gsbux1.uchicago.edu cj...@midway.uchicago.edu
----------------------------------------------------------------------
oracle!us.ora...@uunet.uu.net
> amp is turned on. I always thought that this was normal, but then I noticed
> my uncle's system didn't do it. The 'pop' lasts for about a split second.
> Also, when I power down, as the LED on my power amp slowly fades, this weird
> 'sound' (almost like something you hear in a sci-fi movie - ie. it's not
> just a pop or crackle, but a tone which changes in frequency and is pretty
> high pitched) comes out of both speakers.
accurately>
All amplifiers have power on transients as current is applied to the various
components. Some amps do not enable the output to the speakers until they have
settled; the same applies as power is turned off. Price or quality of the amps
seem to be unrelated to the use of this transient suppression circuitry. My
first real amp was a Mikado received (circa 1966) - power on thump unless
volume was turned to zero as advised in the manual. Pioneer 650 uses
supression circuits; Carver 400t - no circuitry, but no thump, either (with
this amp, any thump was related to whether the preamp sends a signal down the
wire at power up; my Carver preamp suppressed its power on thump);
my previous system, Levinson 23 amp, AR SP11a preamp, Maggie Tympany IV, no
thump. My current system is two Levinson 20.5's - no thump, but the
Infinity IRS IV bass amps thump at power on, though not at full power
(otherwise my windows would disappear in a 2000W/channel windstorm!),
all unrelated to the volume settingon the preamp (Spectral SDR1000).
So I suspect your Adcom stuff is operating normally as long as the thump is not
so loud as to damage your speakers or your ears.
In any case it is advisable to set the volume knob to zero when powering
equipment up or down, as every manual I've read suggests to minimize any power
on transient effects.
--
Ed Oates (my opinions, not Oracle's)
*** Holy ozone, Batman, what a sunburn! ***
Mark Lee Margolis
much more than the Adcom. Great bass extension, and it is of incredible build.
(Large torroidal transformer, high quality parts all around). Plus, they can be
had for around $330-$370. Rated at 100 wpc. It is on Stereophile's recommoneded
components listing, and it has received rave reviews in virtually every
publication that has had the chance to review it.
- Mark
--
**********************************
Mark L. Margolis
ml...@crux1.cit.cornell.edu
fn...@vax5.cit.cornell.edu
William Kucharski
Dimitrius Tzimas <mor...@BOURBAKI.MIT.EDU> said the following:
>Aragon beats Adcom by a HUGE margin. It is better made, uses better parts-
>especially outpout stage devices. It is Apogee's choice of amp. Now, Apogee
>speakers are not known for their high impedances !!
Well, I wouldn't say "amp of choice"; at shows Apogee uses Krell amplification.
Stereophile is partial to Classe amps for the Stages.
>In the same price range, Bryston amplifiers offer superb performance.
Bryston is worth a listen, though they can be a bit harder than most brands to
track down. B&K might also be worth your trouble, though their amps tend to
sound a bit too dark for my tastes.
>In the price range of Adcom, you may want to consider Acurus; they are
>made by Mondial Designs, the same company that makes Aragon. They
>offer a money back guarantee if, after buying their equipment, you decide
>that Adcom sounds better...
The problem I've heard with Aragon amps before (at least older 4004s) is that
they seem to have a bit of a hum problem. While this would be negligible with
relatively inefficient speakers like Apogees, if your speakers are in the 93+
db/watt efficiency range the Aragon may be a bit annoying. (But far from
as annoying a hum as you get with Carver amps.)
>So was I some time ago.....Make sure you audition it carefully with YOUR
>speakers for at least a week.
Always good advice. I upgraded from a GFA-555 to a Levinson No. 27, so take
my comments with a grain of salt. :-)
--
| William Kucharski, Solbourne Computer, Inc. | Opinions expressed above
| Internet: kuch...@solbourne.com Ham: N0OKQ | are MINE alone, not those
| Snail Mail: 1900 Pike Road, Longmont, CO 80501 | of Solbourne Computer, Inc.
| President, "Just the Ten of Us" Fan Club | "Dittos from Longmont, CO"
Dimitrius Tzimas
>ran...@csd4.csd.uwm.edu (Randall Elton Ding) writes:
>
>
> So how do you guys like your Adcoms? Everybody that I know has loved
>theirs, and I am planning to purchase a GFA-545II in the future.
>
> Can anybody name an amplifier line that they feel provides a better
>price/performance ratio? I have heard a 100 watt amplifier from Aragorn
>(sorry, but I can't recall the model designation) that was *sweet*, but
>more than twice as expensive as the Adcom at about $800-900. I don't know
>if the Aragorn is as robust as the Adcom when driving low-resistance
>loads, either.
Aragon beats Adcom by a HUGE margin. It is better made, uses better parts-
especially outpout stage devices. It is Apogee's choice of amp. Now, Apogee
speakers are not known for their high impedances !!
In the same price range, Bryston amplifiers offer superb performance.
In the price range of Adcom, you may want to consider Acurus; they are
made by Mondial Designs, the same company that makes Aragon. They
offer a money back guarantee if, after buying their equipment, you decide
that Adcom sounds better...
>
> All of the low-end Carvers that I have heard sounded shrill and
>really wimpy on the low end. They had a very open sound stage, however.
>
> All in all, I'm pretty well sold on Adcoms.
So was I some time ago.....Make sure you audition it carefully with YOUR
speakers for at least a week.
Jim
John Soucie
fact that the author William Hum was using 3A MM speakers. I read
this group regularly and have yet to see the 3A line of speakers ever
mentioned. This is understandable since they are made in France and I get
the impression that they aren't sold in the U.S or in Britain for that
matter. They are, however sold in Canada. The 3A MM received an
incredible review in the Canadian magazine UHF which is quite high-end.
The bottom line of the review is as follows "There are few
electrodynamic speakers that match its performance. Certainly we know
of no other speaker of its size OR its price that can touch it".
Just as a side note, that issue of UHF also had an interview with the
3A designer Daniel Dehay in which he makes claim to having patented
transmission line speakers in 1975. I showed this to a speaker
designing friend of mine and he went....NO WAY, I'VE NEVER HEARD OF
HIM. Maybe it was a France only patent!
The almost top of the line speaker from 3A is the MS5. It, like the MM
use carbon fibre woven woofers which seem to be gaining popularity.
The guys at UHF magazine liked this speaker so much that they have
chosen it as their reference. It beat out a set of ProAc response two's
as their new reference. The prices are very reasonable even
considering them in higher Canadian prices. The 3A MM are around
CAN$1100 and the MS5 are around CAN$3300.
Is there any reason why they wouldn't bring this wonderful line of
speakers into the US or even the UK for that matter. The dealer that
sold me my set of MM's said they are in the UK but don't get any
exposure because there is a "thing" between the UK and France
(basically: Brits don't like the French!). I find this discrimination
very hard to believe as well as the fact that I have never seen a
single reference to 3A in ANY of the British audio mags.
For me....I think they are incredible and seemed(to my ears) to be
miles ahead of the competition at the CAN$1000 price range. I wanted
to know what William Hum thinks of his since he is the only other
owner that I know of. I may however be moving up sometime this year
since the store I bought them from has a buy up program if I exchange
them within a year and buy speakers that are $500 more. I was
considering maybe moving up to the next 3A model or try and get into
something in the ProAc line or Thiel (all of which they sell) My goal
is to keep moving up for a few years in a row until I own a great set
of speakers in the $4000 range. The only problem is for the next move
up, I am not quite sure if an extra $500 is going to get me something
better then the 3A MM (the model up?!) or something that is just a
little different. I get the feeling that this is a tough price point in
speaker buying; $2K would probably be easier to see a big difference.
Anyways; any thoughts about 3A and it's lack of distribution in the
U.S.. Are there any other owners out there(especially Canada)
--
The opinions expressed here are the John Soucie
opinions of the author and in no way sou...@bnr.ca
reflect the opinions of Bell Northern
Research.
HUM william
am also upset by the fact that nobody else seems to know about 3a speakers.
I myself also find that they are indeed better than anything else in the
$1000 price range. I am constantly amazed by them and find casual
listening difficult because they always pull me into the music and I end
up dropping what I'm doing to listen to them. The only problem/quirk is
that they need a LOT of distance from the walls. (I have them 3.5 ft from the
rear and 3 ft. from the sides - and suspect they would sound even better
with more room to the sides but alas that's all I can spare) Most impressive
is imaging and depth. I don't have any complaints about lack of depth from
CD - and I'm only using an old Adcom GCF-575. For some strange reason though,
they don't sound too good in the stores I've heard them in. I suspect it's
because they use cheap stands and don't bi-wire - actually, the pair they
had in the store couldn't be bi-wired as there were only 1 pair of terminals.
I guess the speaker was updated but the model wasn't changed. I've also
noticed the grill is different.
I don't doubt the theory that they don't get much press in the UK press
because they don't 'like the French'. I've been told by many people that
the British press is not exactly fair and honest. I don't know why it isn't
mentioned in the American press though (besides a review in Stereo Review
about a year ago - but that doesn't count ;-) ). I'd be interested in what
Stereophile or TAS would think of them.
In the meantime, I guess Mr. Soucie and myself will just have to enjoy this
great speaker by ourselves.
Will.
Mike Marks
>You might want to look into the Parasound amps - I just got one. I liked it
>much more than the Adcom. Great bass extension, and it is of incredible build.
>(Large torroidal transformer, high quality parts all around). Plus, they can be
>had for around $330-$370. Rated at 100 wpc. It is on Stereophile's recommoneded
>components listing, and it has received rave reviews in virtually every
>publication that has had the chance to review it.
>- Mark
I also just recently picked up a Parasound, the HCA-1200. This is one
fine-sounding amp, and gets more bass out of my MG-IIIa's than I thought was
possible. Their flagship amp, the HCA-2200, was designed by John Curl,
a former designer for Levinson (their "JC" products) and is a bargain
at $1600. One of these days, I'll need to get one of those.
_____________________________
Mike Marks