• 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.

GM70 - Mono block project


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2017-11-24 11:21 pm
Madison WI
Nice looking build. Reminds me of this future-but-never-going-to-happen 3-500Z push-pull monster amp. I mean, it's not a real tube unless it needs forced-air cooling, right?

I've always wanted to build a monster push-pull amp with transmitting tubes, but the OPT is really a barrier. Even an 811A or 572B (572B is pretty much a beefed up 811A), the plate voltage would be 1200v or so. My thinking is that the OPT would need to be insulated for at least twice that. I assume that the output transformer the OP used was custom wound. I'd be interested in getting more information on it.