High output tube amp
eViL deViL
Where can i find it?
Christoffer
ride...@ride.ri.net
You can look at my home page; you should see a link for a 600W+ tube amp.
It's not easy and it's not cheap (plan to spend at least $1000 US) but
there's nothing like it in the world.
If you use Netscape you can do the right-click thing. If you don't and you
have IE then be patient I'm working on the problem ;-)
Ken Gilbert
Tube Guitar Amp Design/Repair Technician
The Guitarist's Choice http://www.tgcguitar.com
http://www.geocities.com/SunsetStrip/Garage/5701
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
ride...@ride.ri.net
ride...@ride.ri.net wrote:
> In article <ZJGu2.4335$d4....@nntpserver.swip.net>,
> "eViL deViL" <evil....@swipnet.se> wrote:
> > I´m looking for schematics for an high output (450-500W) tube amp.
> > Where can i find it?
> >
> > Christoffer
>
> You can look at my home page; you should see a link for a 600W+ tube amp.
> It's not easy and it's not cheap (plan to spend at least $1000 US) but
> there's nothing like it in the world.
>
> If you use Netscape you can do the right-click thing. If you don't and you
> have IE then be patient I'm working on the problem ;-)
NEWS FLASH!!! (for those who are interested)
The right-click problem is fixed. Users of ANY browser should be able to
LEFT-CLICK on the small pics and get a big 640 x 480 version.
speed...@my-dejanews.com
"eViL deViL" <evil....@swipnet.se> wrote:
> I´m looking for schematics for an high output (450-500W) tube amp.
> Where can i find it?
>
> Christoffer
>
>
I can design an ampliifer for you if you want. This type of amp is hard to
find. It will be expensive due to the custom transformers needed. I will need
to know the type of valves you want. I will only use gas rectifiers, no solid
state! I custom design audio as part of my business.
Mark
Doug
>
> I´m looking for schematics for an high output (450-500W) tube amp.
> Where can i find it?
>
> Christoffer
odd tubes but the design principles are sound,various US tubes are
usable.You need to decide whether you want a Class AB2/B amp or a Class
A/AB design.
You then will be faced with building a power supply to supply the
requisite voltages at the needed currents,having an output and any
needed interstge transformers wound (nope,you won't find any off the
shelf) and the final assembly.
Most people seriously evaluate a project like this and decide they
don't really need a half-gallon of AF out of tubes.If you do it keep in
mind that the power supplies can kill you very dead very easily and that
circuit failures are often catastrophically expensive.I would get hold
of someone with broadcast transmitter experience and tools (gloves,hot
sticks,HV probes,et al) unless I felt very,very confident(and had
tools.)
And ignore anyone who tells you to fool with mercury vapor or xenon
rectifiers.They have to go in an RF-shielded box with hash chokes and
time delayed heater power and you don't need the trouble.Abuse of them
by people who don't care about the RF they generate is leading certain
people to buy up and Widlarize ones floating around hamfests.
Doug
>
> Hi Doug,
>
> >On Tue, 09 Feb 1999 18:48:46 -0600, Doug <dc...@grapevine.net> wrote:
>
> >.Abuse of them
> >by people who don't care about the RF they generate is leading certain
> >people to buy up and Widlarize ones floating around hamfests.
>
A term that has entered the lexicon via Bob Pease. Widlar was an
eccentric engineer that when he ran into a bad part in-circuit on a
prototype,would take the part over to an anvil and beat it into
unrecognizability.(He also designed the first monolithic IC op amp.)
Doug
>
> In article <snip>
>
> This is fine advice, but do you really envision a class *A* 500W amp ??? The
> mind boggles...
I don't but guaranteed,someone out there does.
>
> Also you are correct in stating don't downplay the power supply. After all,
> the circuit can only ouput power as fast as it is tapped from the wall. There
> are very few HV, high current trannys available off the shelf. I have used
> toroids exclusively for the main B+ supplies; the first was a bastardized SS
> 1KVA unit (had to be voltage doubled to get the 600VDC or so), and the second,
> which I am currently winding, is a DIY 1400VA toroid kit from Toroid Corp of
> Maryland. When it is finished it will dispense with the doubler and two other
> aux. power trannies.
I hope you are using the 220V dryer/range/air conditioner feed and not
the 110 here.That's the big secret tweak on any big amp,but especially
with a toroid,any DC offset on the AC line will screw things up
royally.If anyone on your side of the secondary of the utility
transformer is running certain switchmode supplies,this can really mess
you up.
>
> > Most people seriously evaluate a project like this and decide they
> > don't really need a half-gallon of AF out of tubes.If you do it keep in
> > mind that the power supplies can kill you very dead very easily and that
> > circuit failures are often catastrophically expensive.I would get hold
>
> Yes, I've had a couple of failures, one due to a small sliver of aluminum
> flash (from a chassis drill hole) shorting out the grid of a KT90. It got
> beet red in about 5 seconds, and for all intents and purposes it is gone.
> There is no emission left! ;-) The other failure was most likely the tube
> itself, that shattered its envelope and consequently went totally arc-happy.
> Couldn't get to the power switch fast enough...
>
> Remember, if you decide to go transmitting tubes, like 811's, the tranny will
> be HUGE and INCREDIBLY EXPENSIVE. And if you get a tube failure and it runs
> away current-wise, you will simply fry the tranny, and then you'll be in a
> "bad place." I kind of got around that complication by using the
> (relatively) easy to find, cheap to own, Hammond 1650W. Of course, it's only
> rated 280WRMS, but it is simple enough to parallel two of them. They're
> about 200 bucks each, as opposed to 1000 or more for a custom wound class B
> tranny. As stated above, I had a tube run away on me and there was no stress
> at all on the tranny. The DCR's of the primary, if I remember correctly,
> were in the tens of ohms. That's a lot of current necessary to heat those up
> enough to open!
The 811 isn't that big.The 833 and the 4-1000A,is the start of the big
tube range,and they go up from there.The 811 is reasonable except for
the high mu,and there is an 812 that fixes that.
The Japanese run them in positive-grid mode,but that's basically
dumb.You pull grid current and the load impedance varies widely.Use a
tube engineered to do what you want instead of trying to put an aircraft
engine in a Volkswagen,or vice versa.
>
> > of someone with broadcast transmitter experience and tools (gloves,hot
> > sticks,HV probes,et al) unless I felt very,very confident(and had
> > tools.)
>
> Yes, the class B transmitting tube route can use B+ of 1700V or so. That's
> ungodly high, at least for me. EVERYTHING has to be WELL insulated. And
> don't even talk about the caps you'll need to find, or the sea of them you'll
> need to stack to get the voltage ratings. I mean, I take the UTMOST caution
> in bleeding and being very conscientious (sp?), and I'm only using a "paltry"
> 630VDC or so.
>
You use large oil caps,because supplies this big are almost always
choke filtered,the capacity isn't large compared to what is often
stuffed into cap-filtered supplies by tweeks.Obtain and study the books
on big tube broadcast transmitters:every (old) AM transmitter has a big
audio amp of about half the rated RF power for modulation.
dang...@earthlink.net
>On Tue, 09 Feb 1999 18:48:46 -0600, Doug <dc...@grapevine.net> wrote:
>.Abuse of them
>by people who don't care about the RF they generate is leading certain
>people to buy up and Widlarize ones floating around hamfests.
What does "Widlarize" mean?
Regards,
Dangerdave
ride...@ride.ri.net
Doug <dc...@grapevine.net> wrote:
> eViL deViL wrote:
> >
> > I´m looking for schematics for an high output (450-500W) tube amp.
> > Where can i find it?
> >
> > Christoffer
> Get a copy of the GEC book that Old Colony sells. These use some fairly
> odd tubes but the design principles are sound,various US tubes are
> usable.You need to decide whether you want a Class AB2/B amp or a Class
> A/AB design.
This is fine advice, but do you really envision a class *A* 500W amp ??? The
mind boggles...
> You then will be faced with building a power supply to supply the
> requisite voltages at the needed currents,having an output and any
> needed interstge transformers wound (nope,you won't find any off the
> shelf) and the final assembly.
Spot on about the custom IST's... I circumvented the problem somewhat by using
direct coupled CF's (6BQ5's) as drivers so I could push into grid current.
IST's would greatly simplify the circuit, however.
Also you are correct in stating don't downplay the power supply. After all,
the circuit can only ouput power as fast as it is tapped from the wall. There
are very few HV, high current trannys available off the shelf. I have used
toroids exclusively for the main B+ supplies; the first was a bastardized SS
1KVA unit (had to be voltage doubled to get the 600VDC or so), and the second,
which I am currently winding, is a DIY 1400VA toroid kit from Toroid Corp of
Maryland. When it is finished it will dispense with the doubler and two other
aux. power trannies.
> Most people seriously evaluate a project like this and decide they
> don't really need a half-gallon of AF out of tubes.If you do it keep in
> mind that the power supplies can kill you very dead very easily and that
> circuit failures are often catastrophically expensive.I would get hold
Yes, I've had a couple of failures, one due to a small sliver of aluminum
flash (from a chassis drill hole) shorting out the grid of a KT90. It got
beet red in about 5 seconds, and for all intents and purposes it is gone.
There is no emission left! ;-) The other failure was most likely the tube
itself, that shattered its envelope and consequently went totally arc-happy.
Couldn't get to the power switch fast enough...
Remember, if you decide to go transmitting tubes, like 811's, the tranny will
be HUGE and INCREDIBLY EXPENSIVE. And if you get a tube failure and it runs
away current-wise, you will simply fry the tranny, and then you'll be in a
"bad place." I kind of got around that complication by using the
(relatively) easy to find, cheap to own, Hammond 1650W. Of course, it's only
rated 280WRMS, but it is simple enough to parallel two of them. They're
about 200 bucks each, as opposed to 1000 or more for a custom wound class B
tranny. As stated above, I had a tube run away on me and there was no stress
at all on the tranny. The DCR's of the primary, if I remember correctly,
were in the tens of ohms. That's a lot of current necessary to heat those up
enough to open!
> of someone with broadcast transmitter experience and tools (gloves,hot
> sticks,HV probes,et al) unless I felt very,very confident(and had
> tools.)
Yes, the class B transmitting tube route can use B+ of 1700V or so. That's
ungodly high, at least for me. EVERYTHING has to be WELL insulated. And
don't even talk about the caps you'll need to find, or the sea of them you'll
need to stack to get the voltage ratings. I mean, I take the UTMOST caution
in bleeding and being very conscientious (sp?), and I'm only using a "paltry"
630VDC or so.
> And ignore anyone who tells you to fool with mercury vapor or xenon
> rectifiers.They have to go in an RF-shielded box with hash chokes and
> time delayed heater power and you don't need the trouble.Abuse of them
> by people who don't care about the RF they generate is leading certain
> people to buy up and Widlarize ones floating around hamfests.
I don't know anything about the HV tube recs. I went with plain old silicon,
for initial cost, replacement cost (if toasted), surge current rating (there's
1000 mics of caps in my amp), and real estate concerns. It would make sense
though that since I had to tweak the recs quite a bit to reduce the diode hash
(with snubbers and physical location) it would also be a problem with tube
diodes, at least of this ilk.
Good points, Doug.
Ken Gilbert
Tube Guitar Amp Design/Repair Technician
The Guitarist's Choice http://www.tgcguitar.com
http://www.geocities.com/SunsetStrip/Garage/5701
-----------== Posted via Deja News, The Discussion Network ==----------
Ka...@webtv.net
While we're at it, what was a "Boxer engine"?
Were they prone to shorts?
Andre Jute
>
> While we're at it, what was a "Boxer engine"?
>
> Were they prone to shorts?
>
>
I like your pun. A "Boxer engine" is one with pistons at 180 degrees, as
in an horizontally opposed (colloquially "flat") four like VW Beetle or
an horizontally opposed six like a Porsche 911. There have also been
flat eight and flat twelve and flat sixteen engines, most of them
Porsche. Many of the very first engines were flat twos. My favourite
flat four engine of all time was the one fitted to the Citroen GS, a
brilliant little car (spacious, fast, frugal, comfortable) in which you
could make 90mph averages across Europe.
The GS with the 1015cc flat four (there was also a less desirable one
with a bigger conventional engine) had one appalling habit. After a day
spent cruising pedal to the metal, as soon as you throttled back, it
would spew a pint or so of its engine oil over the windscreen... Nothing
to do with the engine, and everything to do with the Citroen
aerodynamicists for once not getting everything spot on; it was caused
by the sudden relaxation of the built-up pressure in front of an
overflow pipe then causing a vacuum and suction. Makes them human, I
guess. I went in person to explain to them and discovered they had never
driven a GS so hard for so long... They thought of it as a junior
repmobile special--no wonder the Citroen marketing department, in any
event never the brightest and the best, let a wonderful little car die
on the vine, except in Britain where it sold itself among the motorway
jockeys.
It was pretty nippy beating up the fenlands lanes too on its air
suspension, unlike the SM coupe which was simply too large (longer than
the Volvo estate with which I replaced the GS as my wife's car when our
child was born) for getting intimate with hedgerows. We only had the GS
a few months as a shopping car while the Volvo was being built to order,
but I would still today choose it over, say, an Alfasud of the same
vintage, or any of the Fiats except the 125 twincam 1600cc which was a
wonderfully nippy car.
Those GS flat fours turned up in several nice open nostalgicar
threewheelers, loose interpretations of early Morgans, that were sold
as kit cars in the UK about the early 1980s. Absolutely looked the
business too with those finned cylinder heads stick out of the sides of
the narrow bonnet.
Andre
--
Andre Jute
an...@indigo.ie COMMUNICATION JUTE
--we support pages for music lovers, writers and audiophiles at
http://indigo.ie/~andre/ComJuteF1.html
ride...@ride.ri.net
Doug <dc...@grapevine.net> wrote:
> I hope you are using the 220V dryer/range/air conditioner feed and not
> the 110 here.That's the big secret tweak on any big amp,but especially
> with a toroid,any DC offset on the AC line will screw things up
> royally.If anyone on your side of the secondary of the utility
> transformer is running certain switchmode supplies,this can really mess
> you up.
Doug, I have been, up to this point, using the plain old 115VAC leads, but I
will tell you this:
I can CERTAINLY hear effects of things happening on the other side (the
primary side) of the power tranny. Of course, I am a musician, and I spend a
great deal of time effort and money on developing my tone, and consequently I
listen very intently as I play. But I HAVE heard weird artifacts, especially
during times of dynamic power supply draw, "ghosting" in the background. I
have every reason to believe that this is due to some DC offset in the donut
primary.
Now, that leads us to our next question: is there any way to minimize these
effects? When you speak of the 220VAC line, is that better because it has
simply less devices hanging off of it, and most of those are purely resistive?
Or does it have to do with the "balanced" nature of the feed?
Are there any ways you know of that can lead one to a better understanding of
what's ACTUALLY happening in there? Any measuring techniques, both on the
amp's PS itself and the power coming out of the wall? Can I simply view this
effect with an O-scope?
So far, the way I've found to minimize these subtle but present artifacts is
to ensure that this monster amp is the only device plugged into it's power
circuit. When plugged into the same one as the bass player, the two large
amps modulate each other. Very interesting to hear...
TIA.
dang...@earthlink.net
That is an interesting piece of EE trivia.
Now that I understand the term, in retrospect, I have Widlarized a few
items myself.
Regards,
Dangerdave
>On Wed, 10 Feb 1999 17:26:51 -0600, Doug <dc...@grapevine.net> wrote:
>dang...@earthlink.net wrote:
>>
>> Hi Doug,
>>
>> >On Tue, 09 Feb 1999 18:48:46 -0600, Doug <dc...@grapevine.net> wrote:
>>
>> >.Abuse of them
>> >by people who don't care about the RF they generate is leading certain
>> >people to buy up and Widlarize ones floating around hamfests.
>>
>
IMJute
From: an...@indigo.ie (Andre Jute)
Date: Thu, Feb 11, 1999 10:31 PM
Message-id: <1dn3fs8.10h...@ts01-003.bantry.indigo.ie>
> After a day
>spent cruising pedal to the metal, as soon as you throttled back, it
>would spew a pint or so of its engine oil over the windscreen... Nothing
>to do with the engine, and everything to do with the Citroen
>aerodynamicists for once not getting everything spot on; it was caused
>by the sudden relaxation of the built-up pressure in front of an
>overflow pipe then causing a vacuum and suction. Makes them human, I
>guess. I went in person to explain to them and discovered they had never
>driven a GS so hard for so long...
automotive quotes:
"I have this Russian military aeroplane designer doing the aerodynamics on a
hunting car I'm designing for an Arab."
Andre Jute 6/5/98
************************************************
"I doubt this particular hunting car will ever go off the tarmac except when on
delivery I demonstrate that it will go faster crosscountry than anything else.
I make it capable of going crosscountry with the best of them, because that is
what I am paid to do, abalso luxurious and fast, because I like repeat orders."
Andre Jute 6/5/98
**************************************************
an appropiate proverb
"As Russians say, if you beat a hare enough, it can learn to light matches."
***************************************************
"Oh, it's functional all right, as a hunting vehicle, with a huge sliding roof
and a shooting chair with more elevating and swivelling and tilting controls
than an enrire Hatteras 60. But it is also functional as a tarmac express, 155
mph worth of express, I'm aiming for. That is what I am doing in a wind
tunnel."
"... a hunting car or any estate is an easy solution to a fast car problem
because the side elevation at the rear gies you a good aerodynamic centre of
pressure the moment you draw the lines..."
Andre Jute 6/5/98
**************************************************
"In the 1960s I briefly raced a 2002 turbo and it was a viciously dangerous
car, more dangerous than the early Porsche 911 or the E-type with its nasty
narrow rear track. The difference was that at least in competent hands the
early 911 and E were useful cars, whereas the 2002 turbo was dangerously
unpredictable in anyone's hands. (I incidentally also had bothe the
Glas-bodied and Goetsch-bodied V8 coupes of that and a slightly earlier period,
and they were wonderful touring cars within their limits. It is now almost
impossible to meet anyone who has ever seen one.)"
Andre Jute 9/26/98
***************************************************
"I should explain that before my mother put a stop to it and I went into
advertising, I had not thought of taking up any profession except what I had
been practising through my university years, which was professional motor
racing."
Andre Jute 2/3/98
***************************************************
"Saying that that nearly-tidy symmetrical ST-70 is a kludge is like saying the
time I bent up new track control arms for my Porsche on a Black & Decker
Workman out of soft ali sheet is a kludge."
"....I fixed the bushes: I put selftappers (sheet screws to the pompous)
through the return from the inside, and used their round heads to hold the
bushes in place by friction."
"My fix was much lighter than the factory's forged and machined crap, and a
whole lot faster around the bends... I raced it a bit, saw it put on another
10K miles or so in our own hands, and the next owner put 120K miles on it
before I lost sight of it, still running on my kludge."
Andre Jute 3/20/98
***************************************************
"But the editor who commissioned the book was a snob who wanted a book
about the Bentleys I turned into racers, and the scratchbuilt one-offs I
designed to order, and some poncy insider-pose stuff."
Andre Jute 5/23/98
***************************************************
snippet from Andre Jute's website
"He holds patents in automobile suspensions, internal combustion
and pipe-laying equipment. Before taking up valve amplifiers he rebuilt old
Bentleys. "
***************************************************
another snippet from Andre Jute's website
"Before taking up tube amp design, for his hobby he designed and built complete
automobiles."
***************************************************
another quote from IM (NOT) Jute
"As the great late Russian leader Joseph Vissarionovich
Stalin said 'When the wood is chopped, the splinters fly'"
sometime in the early 20th century
***************************************************
"You have until sunset tonight, my time, unconditionally to withdraw your
letter. If it is overcast, the sun will set early, so look lively."
Andre Jute 8/19/98
***************************************************
come visit http://www.communicationjute.com for more of your favorite Jutisms.
dang...@earthlink.net
Regards,
Dangerdave
ride...@ride.ri.net
Oooooohhhhh...
Good one Dave (seriously)! It makes perfect sense.
I'll have to go through the collection of motor run caps.
Thinking about it, I'd only need one.
Any other comments on this idea?
SBench
> dang...@earthlink.net wrote:
>> Cap couple the line AC to the power torroid.
>
>Oooooohhhhh...
>
>Good one Dave (seriously)! It makes perfect sense.
>
>I'll have to go through the collection of motor run caps.
>
>Thinking about it, I'd only need one.
>
>Any other comments on this idea?
>
>
>Ken Gilbert
>Tube Guitar Amp Design/Repair Technician
>The Guitarist's Choice http://www.tgcguitar.com
>http://www.geocities.com/SunsetStrip/Garage/5701
Hi,
Bring up the system slowly to make sure you don't
happen to set up a series resonant circuit (which would
place more voltage on the unit than you think).
After you think you're OK, make sure to measure the
voltage across the primary.
Best Regards,
Steve
Check my web page .. <A
HREF="http://members.aol.com/sbench101/">http://members.aol.com/sbench101</A>
Remove the .gov to EMail me
Ralph and Diane Barone
>Cap couple the line AC to the power torroid.
>
>Regards,
>Dangerdave
>
>>Now, that leads us to our next question: is there any way to minimize these
>>effects?
I saw a schematic somewhere that had caps in parallel with a set of diodes
something like this:
+---|>|---+
| + + |
---+-|(---)|-+-----
| |
+---|<|---+
I believe that the diodes allowed just enough DC bias to keep the core out
of saturation and also provided protection for the capacitors in case the
transformer was hit with a real big offset (say from energizing at a bad
point on the wave).
Brad Thompson
Hello--
You need to double-check your diagram, because the network shown
amounts to one diode-voltage drop in either direction.
You perhaps meant to put a diode across each electrolytic such that
a reverse-biased 'lytic is bypassed by a forward-biased diode?
73,
Brad AA1IP
Mike Thompson
Ralph and Diane Barone
Brad Thompson <Brad_T...@pop.valley.net> wrote:
I found the reference and have appended the entire post verbatim. There's
a bit of a difference between what I remembered and what was actually
posted, but I think the concept (cap couple the AC line to the toroid, but
use diodes to limit the amount of DC bias) is the same in both cases.
------------------------------
From: dun...@Lise.Unit.NO (Thomas Dunker)
Subject: DIY: Shutting up buzzing toroids w/filter
What follows is a filter designed to remove DC components, noise, transient
spikes and other crud which can cause PSU transformers (particularly toroid
types) to emit mechanical hum, and also to contaminate the supply voltage
in general.
It was submitted to a Danish Hi-Fi magazine, and the designer said it
worked well. I have not built it myself, and I urge you to notice how the
diodes should be connected (each pair of diodes has one diode pointing
either way). Don't blame me if something goes wrong. I post this because
there was some interest in ways to eliminate mechanical noise from toroids
on the newsgroup, and that's what this circuit is supposed to do. I think
it would be a good overall line filter used anywhere in a system. The
filter was designed for 230V line voltage. Do the necessary adaptations as
you please.
Here we go:
*--*---D1--*--------*----------*---CHOKE1---*--------->
| | | | |
*---D2--* | | |
| | | | |
AC *---C1--* | | | To
Mains VDR | | Transformer
SIEMENS C3 C4 Primary
*---C2--* S10V S14K250 | |
| | | | |
*---D3--* | | |
| | | | |
*--*---D4--*--------*----------*---CHOKE2---*--------->
D1=D2=D3=D4=1N5404 DIODE (D1/D2 connected opposite ways, do. for D3/D4)
C1=C2=Electrolytic Capacitor, 16V 2500 uF or more (make sure they can
take
required ripple current(AC current)
VDR=Voltage Dependent Resistor(Transient protector), suggested Siemens
type
or suitable equivalent
C3=C4=630V film capacitor, 0.1 uF or greater
CHOKES= for HF suppression, use types with sufficient current ratings and
inductances around 10 uH. Many good toroid type chokes are
available.
Comments are welcome, and I'd like to hear about the results, as I plan to
build some myself.
Good luck!
Thomas,
<dun...@lise.unit.no>