by Lafish » Fri Dec 27, 2019 2:03 pm
Posting here instead of the ST-35 forum because this one is more active. But the bias pots on my Rev. B St-35 no longer seem to do anything. Bias stays in the vicinity of 350mV, plus or minus less than 10 percent, no matter where I turn them, and with the power switched off, resistance at pin 3 likewise stays at about 450 ohms. This is not a huge problem, as the readings are close enough, and the amp still sounds fine. But it's a curious thing. I kind of doubt that all four pots have failed at the same time. The amp has been in more or less constant use since I built it in 2002 or so.