i hooked up my HK receiver to the multi zone of my 950 preamp and get a humming noise. i tried different inputs with no luck. this humming noise is present even when the HK receiver is unplugged. i thought i had a ground loop problem, but why would this happen when i unplug the receiver? i'm lost. i've tried two different cables of decent quality. the length is about 35 feet. both systems are plugged into Monster Power 3500 units. any ideas? thanks for any help.

Hi,
You say you have about 35 feet of cable between the two units. Is that cable run alongside AC power cables? If it is, it can be picking up the hum from that. Keep audio cables and power cables seperated as best as possible.

HTH,
Peter

I concur with phogandive - the most likely culprit is that 35-foot run picking up noise from power cables or even speaker cables.

i thought of that and ran the cable right down the center of the room. no power cables at all. still got the hum. maybe i guess i will have to try a more expensive cable.

If your equipment allows it, you might try moving the HK closer to the 950 and trying a short cable to see if the cable is the culprit.

Also you might try one step at a time. Just the cable plugged onto the 950, with no HK plugged in and see if it hums. You can also try the cable coiled up, and then stretched out...then plug in the HK and see if it changes. If you get a different cable, see if you can get sheilded cable, or if both units will allow it, optical.

Peter

sounds like a ground loop to me. try a radio shack $17 ground loop isolator to put in series with the audio outputs from the hk. if cable tv is in anyway connected to the hk, it could be a ground loop via dc on the coax.