Diagnostic process, more or less as it went down:
- Open the thing up. Nothing really looks amiss.
- While open, hook it back up and plug it into the amp. Not sure what I expected to accomplish here, but why not.
- Start twisting knobs. I realize the hum goes away when the volume is all the way down (no surprise), but also, strangely all the way up.
- Notice two little dings on the volume knob.
- Reassemble, go back to jamming with the volume maxed and the gain down for a bit, because (not now, chief!) I was kind of in the zone.
My hunch is that the thing landed on my footswitch volume-knob first, and something broke inside the pot. It's not an impossible situation because it still works quite well as a boost like this, but it makes blues jams a bit tricky. So... Does this diagnosis sound about right, and considering my soldering is about on par with Chris's string changing, how likely is it that I could not make matters worse by trying to swap the pot out myself?