Never heard an amp do this before, ideas?

I have a primaluna 100 unplugged from any inputs. It has this awful high pitched sound coming from the speakers when it's turned on. It happens on both channels, and through headphones.

I have turned off all electricity in the apartment, turned all breakers off except the one it's on, moved the amp around the apartment, tried a humx, and different power cables. I even replaced the unit with another primaluna and they both do it.

I'm running out of ideas, anyone ever seen this before?



Have you tried a Ferrite Ring Core RFI EMI Noise Suppressor Cable Clip, you can find them on Amazon and eBay? I had a serious issue with rfi in my system, I could hear the local am radio station broadcasts. I bought a package which included several different sizes that I was able to put on all cables attached to my amp and throughout my system. It offered me quite a bit of relief. I hope you figure out the problem, I know what it frustrating experience this can be.

When I had to live in an apartment I had an upstairs neighbor who played his stereo so loud that it disturbed my piece, quiet, privacy, and my right to choose for myself what music I wanted to hear. He bullied me with his trashy music when I asked him to stop. The landlord and the police refused to help me. My solution was to construct a microwave horn using microwave oven parts to disable his stereo. I wore a suit made of wire screen for my own safety. (Unprotected by laws and rules of common decency I did not care about the safety of my bully.) The microwaves got into the circuits of his amplifier and caused it to buzz loudly because the power supply to a microwave oven magnetron is a voltage doubling half-wave diode-capacitor system. 

Are you playing your music at a volume that violates the privacy of your neighbors? It is unlikely you have a neighbor who is fighting back if you are, but everybody who plays a stereo has a responsibility to respect the right of others to say no to music they do not want in their homes even if no law enforces it.