Hum hum hum


I have connected my NOS PS Audio gca 250 to my PS audio pre. Disconnected all inputs and I get a distinct hum at high levels on one speaker with just the amp/preamp/speaker connection. . Swich the xlr cables and the hum goes to the other cable. I probably will never play at these levels, but I would like to trace and fix the hum. Any ideas? Thanks.
128x128nimbus109

Showing 1 response by lowrider57

https://www.musicdirect.com/equipment/cardas-cgsp-xlr-shorting-strap-ea

When xlr and rca inputs share the same circuit, you need to short pins 1 & 3 of the xlr inputs to avoid noise thru the rca connection. But always check if the manufacturer recommends this.

Since PS Audio components are fully balanced, I don't know if these are needed.