When the pre-amp turns on it goes away and there is no hum. Does this mean I have voltage leaking into the chassis or something
that the pre-amp is grounding out when it gets turned on? Touching the amp during humming seems to change hum and there maybe even is a little shock, very little.
If this is the problem, where should I look? The wiring all seems kosher to me, so I'm not sure the most likely places to look.
This is one of Bob's kits by the way.