I'm having a bit of an issue with my unit, which I have narrowed down to the OP-AMP. I've got an Audio-GD moon, and after 4-5 hours of being on, I get a low level hum that doesn't go away with a power cycle, but does go away after it cools down. Any ideas on what might be wrong?
Also, what's the bees knees on opamps? Is everyone going for a OPA627 with a class-A bias mod? I'm really in love with the Moon OPAMP, and I'd like to figure out what's going wrong here. It's a very full sounding opamp and really improves over stock.
I've had the same low level hum with all op-amps I've tried. I think it's a issue within the M-Stage or a ground looping issue. Some input on this would be appreciated.