Home Forums Design and Building 2 Stroke Amplifier Design and Building But there is no sound, except for a hum … Re: Re: But there is no sound, except for a hum …


Probably not the voltages. Check all the grounds for continuity, check for grounds where there should be none. Double check the input jacking wiring, the shield goes to ground (important: one end only), the center lead goes between the tip lug of the input jack and pin 2 of the preamp tube (the 12AX7). Double check all the solder joints , post some photos if possible. Let us know if it resolves the issue. There are other things to check so, do this first and report back. Be sure to use a current limiter so you done create a short and fry anything (like a transformer).