Getting a hummer

[@ob_gyn_inc]

Yes, indeed. Audi equipment, anyway. I need something to keep me busy when it is snowing outside.

[@ob_gyn_inc]

@HenrydeBeli Yeah, I fixed it alright. I went out and bought a Dynaco PAS-3 preamp and got on with my life. What project do you have ground loop issues with?

[@ob_gyn_inc]

@HenrydeBeli I'd try a commercially available ground loop isolator. If the hum is a 60 cycle (50 cycle if you live on the other side of the pond) and sounds quite a bit like mine, I'd be willing to bet it is a mismatch in the ground impedance. There are tricks to make this better, but if I were you, I'd go ahead and buy a ready-made one. (Note: You'll have to put isolators on ALL inputs going into your amp) Good luck!