What am I hearing from this amp?


I recently bought an Anthem MCA5 series II amp to add to my Integra 8.2 receiver and Kef ref 2~2 speakers. With the receiver connected to the speakers,the speakers are dead quiet with any setting on the volume knob. I added the amp from the pre-outs of the receiver with my 5 speakers hooked to it. At -55db from the right front channel I could hear a slight hiss 9" away from the Uni-Q driver(mid and high). I could hear a quieter hiss from the left front channel. All other channels were dead quiet. I unplugged all the interconnects leaving the speakers hooked to the amp. I then heard what sounded like air moving from the same speakers, but the hiss was gone. I could switch the spkr connects and the sound would move to whatever was connected to the front right and left channel. Is this a ground loop hum? or something else?
The amp went to Anthem and they say nothings wrong with it. Any suggestions or thoughts would be appreciated.

Mark
mark_lp
I would say that when you don't hear the "hiss" from the receiver and hear it from the receiver/amp combo it is just the added amplification. The hiss probably present in the receiver but not noticable until the amp amplifies it.
Also it may be a RFI/EFI in the cabling between the receiver and amp that you're picking up. Try a sheilded cable
A hiss heard from 9 inches away is normal for most gear. If it was very noticeable from 9 feet away you might have a problem. There's lots of things in life to worry about, but this isn't one of them.
Are you hooked up with cable TV? If you are, disconnect the feed and listen again.