My Crack + Speedball has a buzzy hum that becomes audible when I turn the volume pot up to 50 % or more. I believe I had it before the speedball upgrade, but then at 80-90 % and up. I have tried different tubes with no change. The noise is also the same if I disconnect the DAC from the input.
After reading the forum I'm pretty sure I have a bad solder joint somewhere, but from the information above, is it possible to pinpoint where it could be? Before or after the volume pot?
Thanks in advance!