WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Here ya go guys, a place to share pictures and a brief explanation of your favorite amp or latest project. For discussion or an in-depth writeup, let's post at the Discussion Thread. Hope this will suffice- Who's gonna start things off? (again)
Guess I'll keep the ball rolling- This is my second attempt and current finished amp, based on a '40s PA design by Valco. Typical 6L6 PP. IIRC, the xformers are 30w Hammonds. Finished this one a couple years ago and still sounds pretty good, although there's some low level hum that still drives me nuts.
Shot of the back- 5 inputs, inverse fdbck switch, switched outlets. The chassis is done in black metallic, with light blue metallic sparkle that you only see when the light catches it, then a clearcoat over that.
All lit up like Christmas! The vol knob and top circle are EL panels. One step closer to high-tech, I included a delayed HV startup ckt that still works Thanks for letting me dust off the ol' amp and share! Who's next!?
Angela/Sound Practices WE91 based 300B SET with Electra-Print output transformer, ASC oil caps, Sylvania 6SL7 driver, Mullard GZ37 rectifier, WE300B, stainless/mild steel sandwich top plate on South American mahogany base.
Thought I'd throw in my brother's 6sn7/300B P-P monoblock that is finally becoming a reality. It was built in partnership with an old friend of his. Chas(my brother) was responsible for the layout and construction of the chassis(machining, veneering,etc.,), while Mike designed and prototyped the circuit.
It's made of polished aluminum plate and veneered mdf, and has hundreds of hours put into the machining, etc., (for all four units). The transformer cover is fiberglass that was laminated over a mold and will have artwork applied.
And another picture of one of the best sounding and also the vey cheapest PP penthode amp I have ever build. Had cost me about $75,- and beats every EL34 amp I have ever heard. It's completely build with military dump material wich cost about nothing. I really don't know wat I did but I never managed to build a better sounding penthode amp, even with the same tubes, better transformers and a lot more expensive parts. Just lucky I guess. It's build fully hardwired with ultrashort signal path a'la gainclone (didn't know at the time of building) and the whole thing is getting HOT HOT HOT, very HOT, every part of it, but it still work after 8 years.
A closeup of the winding so far. This layer is 110 of 450T (three layers hidden beneath this) which will be the first of four sections for the primary winding. 10mil of HDPE insulation will go over this before the secondary is wound on top, and so on.