Ground Loop Question

Maybe this will help.

Pass Labs Ground Loop Hums

Cheers,
John

the hum is coming from the speakers, there are several groups of lights in the basement where the rig lives, one of these sets if you turn them off the hum drastically decreases.
He has a lot of stuff hooked up, a turntable, DVD player, CD player, VCR, Tape Deck, digitital cable box, and everything runs through his MONSTER HTS3600 power conditioner.

I think i might try getting a couple cheater plugs and just disconnecting everything and bringing everything back in one at a time. All of his cables are MONSTER cables and somewhat decent ones at that, the power and audio is all run together with no attention to placing the audio/power at 90 degree angles(drawback to using a mass market retailer for an install). I guess one way to isolate if it is the transformer in his reciever (pioneer elite 36 model) would be to disconnect everything and try the radio with nothing else hooked up. He does have an HDTV with the audio from the cable box being fed to the reciever, i think he is using COAX or Fiber. will take a better look sometime.

This guy's system is a pretty decent mid-level system, i know that he is completly happy with his choice of gear, but im sure he would appreciate getting rid of that hum.

Thanks for all the responces, i think i have a good strategy as to how to get rid of this hum.

I have a similar problem, with audio humming caused by several-different devices IF the 3-wire powercords are plugged into 3-wire outlets. My solution is as above--float the ground pin with some kind of cheater plug. While you're doing this, try to orient the remaining 2 wires to achieve the lowest voltage (measured to a grounded outlet centerscrew) on the chassis (with all signal cables disconnected). I've seen up to c. 60vac on a chassis when the remaining 2 sprongs are oriented the wrong way.

BTW, HUM from ground loops is caused by 60Hz AC-power current flowing between components thru the SIGNAL cables and somehow modulating that hum into the signal-carrying circuits. Understand that floating the 'green-ground' pin leaves some of that voltage previously drawn to some ground still on the chassis.
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Sugerbrie is correct, single-point ground is ideal way to isolate ground loops. To further improve ground loops, a ground lift is the best.

I had the same problem with my HDTV system using a Krell HTS connected to a Pioneer Elite DV-38 CD/DVD player and a Pioneer Elite PRO-730 RPTV. The CD/DVD player was connected to the TV via a component video cable (RGB). Absolutely terrible hum when the HDTV cable box was connected. The hum was coming from the HDTV cable box, to the TV, then the CD/DVD and eventually pre-amp/amplifier. The problem was eventually eliminated by replacing the copper coax digital interconnect between the Krell HTS and Pioneer Elite DV-38 with an optical interconnect, no hum at all now. I also had some success using a #XA-63400 ground breaker ($7.45 from www.hometech.com ) between the cable box and TV.