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.
Hi all. I have determined the problem and it's quite mundane: the 12J7GT error amp was getting 6.3V heater voltage. After supplying the proper voltage all is well (and makes perfect sense, of course). I thank you all for your suggestions; i learn from you.
