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?

 

hobbes101

@oldaudiophile led lights on dimmers, a WiFi router, hvac, and refrigerator. A few switching power adapters plugged in throughout the apartment. Florescent lights in the bathroom.

 

All of these things are suspect to me, most are pretty far from the unit. I've shut down breakers and made sure lights/hvac/wifi/refrigerator are off without effect, though.

 

​​​​​​I'm in an apartment on the 4th floor in NYC. About 8 floors up is some Verizon equipment. Across the street there is a big service elevator.

 

part of me is thinking I should find a way to locate the RFI noise somehow, but I'm not sure how.

Do occupants of nearby apartments in the building hear the same with their stereos?

Bring the unit to another location and give it a whirl - I had something similar happen with a Mesa Boogie Dual Rectifier 4x10 "Blue Angel".  Ultimately in my situation there were two problems - one was RFI at my location (which was clear after moving the amp) and the other was a bad capacitor. A quick repair to address the 'singing cap' and we were good to go (especially once I moved to a new apartment and the amp had a friendlier environment).  Unfortunately, I sold the amp to pay for my first wife's engagement ring... woof, did I get it wrong with that one lol :D :D :D