How to Eliminate Hum? CDP + Pass Preamp + Amp Setup.

Try a different outlet on a different circuit completely it cold be that something on the line is affecting the setup.

I’d suggest calling Pass Labs directly or drop them an email sooner than later. Doesn’t surprise me you’re integrated isn’t having a ground hum as it’s one device not two on the same circuit. For the fun of it, off another electrical circuit such as another part of your home, run a long extension cord to the preamp and see if that changes things... make sure it’s indeed a separate circuit so you might have to flip some panel breakers. Are you sure the receptacles are indeed grounded and not just an outlet with a ground socket and the ground is only floating? I wouldn’t suggest it long term but go to any hardware store and buy two cheaters to float the ground on both the preamp and amp; if the buzz is gone it’s likely an electrical issue and then call a electrician for the fix. That preamp and amp should be dead quiet even with very efficient speakers.

Are you running balanced IC’s or single end? If single ended are the pins in the XLR sockets on the amp? If you’re running single ended you might want to try balanced.

I’m going to relocate the Pass XP-22 to another room. I’m using unbalanced RCA IC. I’m going to call Mark @ Reno.
I used the Pass X250.8 with my D. Sachs 6SN7 Tube Preamp - Dead quiet!
I ordered an Emotiva CMX-2 (Humdinger was out of stock). I’ll try the Cheaters too tonight.

With the XLR interconnects, the Preamp & Amp are dead silent! I wonder why the RCA connection produces hum?