I just got a '74 PR that has been(at least) partially Blackfaced and has pretty new doghouse caps. Once I biased it with new 6l6's, it sounds great except that there is low level 60hz hum and the reverb is noisy- it sounds like a ground hum. When I turn the reverb up, the 60hz hum is attenuated, but the grounding noise increases as the reverb is increased. I check the cables and changed the 12AT7 driver, but that's as far as I've gotten.
Any thought on where to look?
Any thought on where to look?