parasound zDac owners - quick question

You may have ground current problem at your house.Ground loops are a major cause of noise, hum, and interference in audio, video, and computer systems. Try using balance cables on your system or eliminate the ground to test with an adopter or transformer.
I used z products with no such issues.

Hi beewax
Thanks for the response. Im glad to hear that you have avoided the issue. I would agree that I probably have bad power. I have 2 zamp v3's, both of which hum (one isnt loud.) But I have 4 other amps with toroid transformers, and none of them hum at-all.
This zdac is the loudest, by far. Ive tried it in three different power conditioners, in different outlets, in different rooms...all the same result...even if its not connected to an amp or anything else.
Im thinking about taking it apart and see if it could be tightened or something applied to dampen it. Its pretty nuts. But I dont want to void the warranty.

I have zdac with no hum

Mine hums, and it's definitely audible from a foot or so away. I emailed Parasound about it. Richard Schramm attributed it to the toroidal transformer; he said some hum is normal, but it will be worse depending on the power in the home, dimmers, etc. I don't hear it from across the room like I did with an old Unico integrated amp I once owned (that hum just about drove me insane). It may be worth opening it up and seeing if you can tighten down the transformer a bit (while unplugged, of course). I have not tried this, but it could work.