Another Hum question


So I just noticed a slight hiss / hum coming from both speakers, both drivers in each. Left speakers hum is slightly louder. I disconnected everything from the amp and it's still there. The only way I've been able to get it to quiet down is by hitting the switch on the back of the amp from unbalanced to balanced, and then there's no hum, just a very very slight hiss from the tweeters that I could live with. The amp is a classe ca 150. Any thoughts? Thanks for any input!!
128x128b_limo

Showing 3 responses by xti16

Xlr's fixed the hum :-)
Still sounds like a ground loop somewhere. I had the same problem when I had my Bryston. My brother in law had the same problem with his Classe cdp and Bryston and for him balanced cables resolved it. For me I had the B100 which didn't have balanced and lifting the ground from my power cord solved the hum until I switched to an Octave intergrated.
B_limo you should be fine. Only if you go back to rca will you need to address the ground loop.
A cheater plug is the same as lifting the ground. Normally it isn't a problem. Key word is normally. When I had the problem I could lift the ground on either the Bryston or my Meridian G08. I chose the G08 because is has the lowest current draw. That was something I was taught when I worked for TI with very large 'current' draw devices in computer systems (yeah the big 250 lb 25 mb disc drives). I even tried using a 2KVA isolation transformer with a balanced output. It cut the hum down a hair but also changed the hum to a buzz. I think the Xlr's is the best choice.