The Amp Garage

I am assuming that your reported -57 is what you had before you replaced that 10K resistor in the bias circuit, if not then the bias voltage is still too high! What was going on before you replaced that resistor was that the output tubes where not idling and pulling current, in that state the power...

Stevem wrote: ↑Wed Mar 02, 2022 11:52 am With the amp in play mode what do you have for voltage at the input to the choke, and as noted on the schematic what do you have for negative bias voltage ?

input to the choke: 438v, negative bias: -57,3v

Check the value of the 22k PI tail resistor by measuring from where you have marked 149V to ground. It may have drifted up. you're absolutely right, I took it off the circuit and it measured 54k, it was the only one in that area that I hadn't replaced. I have now put 10k + 15k in series and the vol...

bepone wrote: ↑Wed Mar 02, 2022 5:07 am

nabokov wrote: ↑Tue Mar 01, 2022 10:58 pm Hi anyone can help? wrong voltages in red

voltage after rectifier diodes? looks like phase inverter tube is higher , maybe too high input/wall voltage

the voltage after the rectifier diodes is 329v, I only highlighted the voltages that seemed too different from those in the schematic

Hi anyone can help? wrong voltages in red