Unknow amp

[SISKO]

Hi.
Well, some days ago i bougth an old tube amp. It has 2 el34, 800v plate, and it says 100w guitar amp.
Could this be possible?, i mean can 2 el34 give 100w?.
Also, anybody know of a comercial amp like this? Schems?
Thanks

Rock on
Bye
SISKO

[AL]

  You don't mean 800V plate voltage correct? You would need to call the fire dept. Two EL34's would give you around 50 Watts. You're probably going to get more out of it when it's pushed but rule of thumb - 2 x EL34 = 50W and 4xEL34 = 100W.

As for a schem. There are a ton but you're going to have to give up some more information. Is there a name on the amp? Combo? Head? How many pre-amp tubes? What type of pre-amps (12AX7)? Rectifier tube? SS rectifier? What does the tone stack look like?

AL

[SISKO]

You don't mean 800V plate voltage correct?

I DO really mean that it has 800V plate voltage 
That was the amazing thing.
So, being a preety "unique" amp i was seraching for a schem. I know there are tons of schems, but i was asking for the ones that has 800v and 2 x el34, overall they should be more or less the same.

Its a DECOUD amp, but i dont know the model. Its a head and has 6 preamp tubes, (2x12at7, 12au7,3x 12ax7) Its sillicon rectifier.
It sounds preety fender-ish to me..
Thanks

Rock On
Bye
SISKO

[bancika]

I don't think it's possible for EL34 to work with 800V plate voltage. Anyway, go to ax84.com and ask...you have better chance

[Seljer]

Pages all over the internet list 800v as the maximum plate voltage for el34s though, so it might be possible

[R.G.]

If I remember correctly, Traynor used EL34's with very high plate voltages to deliver high output powers by running the suppressor grids at a substantial negative voltage.

[dano12]

If I remember correctly, Traynor used EL34's with very high plate voltages to deliver high output powers by running the suppressor grids at a substantial negative voltage.

Speaking of amp design, I have to ask you about the Visual Sound amps you helped design:

1. A bias knob with LEDs. Brilliant idea, why doesn't everyone do that? It is so self-evident. Does your scheme allow slightly cold or hot biasing (i.e. just barely light up the LED for a visual indication?)

2. Stompbox power outlets on an amp. Yep, certainly the touch of a guy who knows about pedals.

Anyway, sorry to hijack the thread. Just wanted to point out its the little things in life that make gear cool.

[Sir H C]

EL-34s can work at such high plate voltages but the grids need to be connected differently so that they don't see that voltage.

[JimRayden]

Seeing the pible for tubes, TDSL at duncan amps:
http://tdsl.duncanamps.com/show.php?des=EL34

At 775V of anode voltage, two of them do put out 100W.

You don't mean 800V plate voltage correct? You would need to call the fire dept. Two EL34's would give you around 50 Watts. You're probably going to get more out of it when it's pushed but rule of thumb - 2 x EL34 = 50W and 4xEL34 = 100W.

As you see, sometimes thumbs don't work. This amp seems to belong to one of the other four fingers.


Sorry, can't help identifying this amp, just pointing out that 800V would work and this is a marvellous find of an amp.

----------
Jimbo

[AL]

At 775V of anode voltage, two of them do put out 100W.

Well, I'll be... Learn something new every day.

There are a load of Traynor Schems here

http://www.lynx.bc.ca/~jc/traynorSchmArchive.html


Perhaps the power layout is similar to what you have. Wow !! That's a lot on the plates. 

Just out of curiosity - what brand of EL34's are in there? Old tubes? I wonder if newer tubes can handle that?

AL

[SISKO]

Just out of curiosity - what brand of EL34's are in there? Old tubes? I wonder if newer tubes can handle that?

AL

They are old. When i put my fingers on it, the labelling just disappears. I could HARDLY saw the "el34" labell. Altought, it has the same structure of an el34.
I'm gonna check those schems.
Thanks

Rock on
Bye
SISKO

[R.G.]

1. A bias knob with LEDs. Brilliant idea, why doesn't everyone do that? It is so self-evident. Does your scheme allow slightly cold or hot biasing (i.e. just barely light up the LED for a visual indication?)

It's pretty flexible within certain limits. The basic amp has the "green light" be a very thin window, so that you get "good to go!" at a no-fudging, no-guesswork place every time. But knowing that people like to bias slightly hotter, we put in two pre-set bias settings for each type of tube. You set the tube selector switch to 6L6, a hotter 6L6, eL34, or a hotter EL34. I picked the target bias settings based on a long series of interviews with techs and players whom I pumped for "what's the *best* bias setting?" Those answers actually clustered pretty strongly.

The design makes it possible to set the target bias currents to anything reasonable. Our goal was to make it easy for a non-techie working musician to just pop in a new set of random tubes and get back up on stage, and I think we acheived that. We discontinued the microcontroller self biasing setup because it turned out that the red light / green light system was just too easy. On all the prototypes, I don't even bother worrying about pairs of tubes or matching. I pop in a new pair, let it warm up and diddle the control for two greens - all done!

I nixed the early variable-target design because it was not consistent with the working musician model. There are four presets, to keep it simple.

2. Stompbox power outlets on an amp. Yep, certainly the touch of a guy who knows about pedals.

Thanks!

What's making me nuts is that I finished those designs a long, long time ago, and the path to actually getting them manufactured has been as frustrating as anything I can personally remember. That's a consequence of the "working musician" paradigm again - they have to be affordable to a working guy, and that means that boutique-style prices are out. Anybody with moderate skills can build a dozen of anything - but make me a thousand, and have them here by next month - that's another story. But I *can* tell you why it's hard to find really high quality, sturdy equipment at a good price anymore. I have the scars.