Home Forums Design and Building Effects Design and Construction Following 2 Power Tube Amp Design Re: Re: Following 2 Power Tube Amp Design


I’m not concerned on the rectifier voltage as much. You might check your AC power. That tends to vary from place to place so if your AC Voltage is like 110V vs. 120V, the amp voltages would be lower.

You are correct on the tube voltages seeming high. Check pin 1, and pin 6, right at the tube socket. Those are where it should be around 140-160 range. Though, if you test on the power supply side of the 100K resistor, it will be higher, likely in the range you measured.

As for the input, that sounds like a problem ;) If you measure with an ohm meter, at pin 2 of the preamp tube, and then at the tip part of the input jack, you should have 68K. No continuity tho. If you dont have continuity from the Tip to to the 68K resistor, then there is definitely a problem and it wont pass signal. Likewise, if there is continuity from the tip of the 68K and ground, there is a problem.