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
59 views, no responses? I called Classe today, once I learn French I'll get back with you on what I was told.
Sounds like a grounding problem (hopefully) rather than a caps problem (not so good) since it goes away in balanced mode.
As to what to do about it... check your power cord and the mains plug. Failing that, I think you're better off speaking to a technician.
Of course the french explanation will prime over all of what any of us have to say.