• 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.

Use for 4k PP (non UL) OPT's?

Thanks man, Hows your 833a project? get that thing in a chassis yet?

No, I came to my senses and decided that it just didn't make sense. If I could find a suitable OPT it would cost far more than I was willing to spend, and the sheer size and heat load does not make sense in my small house in a hot climate.

I dig the 6GV5 and the 6JM6, Is there a better of the 2?

The guts of both tubes look about the same, so go for whichever one that you can get cheap. The 6GV5 was on the dollar menu at ESRC befor this board came along and wiped out the supply. There are dozens of other tubes that will work in that board too. Read through the entire thread for some numbers that are plug in compatible.
 
807s?

I don't see why not.

It is listed for class AB1 and AB2 audio amp and modulator output.

P-P impedance all the way down to 3000 ohms. No distortion data though so that is an open question. It will work, but how will it sound.

807 is derived from 6L6 with top cap for higher B+ so I would expect it to sound fine.