Originally Posted by
Simon_LDT
Ever since introducing separate Pre and Power amps into my set-up I've had humming coming from my speakers, which I am 99.9% sure is a ground loop. I'm currently running an Emotiva UMC-200 and Nakamichi AVP1, before that I was using my old Sony STR-DA2400ES as a pre into the Nak and also had the humming. Before I ever introduced the Nak I was using the Sony AVR solely and had no humming at all.
When the power amp is connected to the speakers but not the pre, there is no humming so that eliminates the power amp. Soon as the pre is connected up using unbalanced RCA cables the hum appears - before ever connecting any other leads in the pre itself. I can only assume (after thorough research) that because both amps have 3 pin power cables that both are trying to ground and it's throwing something off. Both are plugged into the same power socket via an extension.
What are my options to remove this ground loop (and safely)?
I've read that making up a piece of speaker cable to go between them and connecting it to a screw in each chassis is an option but is that even safe, and will it even work?