Ground Loop Hum

[Polkitup2]

I added a separate amp to my system and now I have a 60 hz hum. The hum disappers completey if I disconnect the front speaker pre-outs from my receiver to the HT bypass inputs on my pre-amp. I tried numerous different scenarios using different circuits, trying everything on the same dedicated circuit, different cables, unplugging everything, cheater plug, etc. Depending on what I did, I could increase the hum or lower the hum but never get rid of it entirely unless I either unplugged the RCA cable from my reciever to the HT bypass input on the pre-amp, or used a cheater plug on the new amp. Doing either of these would give me dead silence but of course I would like to use the HT bypass and I am not sure it's safe to run the amp with a cheater plug. I guess I was somewhat surprised that when I had all components connected to one power center on one dedicated circuit I still got a slight hum. Any ideas on how to fix this?

[RuSsMaN]

The hum is more than likely related to a video source. Start disconnecting them one by one, Satellite, cable, playstation, etc to see where the issue(s) are.

Cheers,
Russ

[dpowell]

Try unplugging the coax cable from your cable TV box and see if it clears up. If so, you may need to grab a Jensen ISO-MAX VRD-1FF. Did the trick for my system.

[Polkitup2]

Yep, I forgot that I had the cable feed running through the power center. I disconnected it and 99% of the hum went away. So now now I can either not have cable, not be able to use HT bypass, or run with a cheater plug on my amp :D

[Polkitup2]

Good idea on the Jensen, that's sounds like my best option. Thanks guys!

[dpowell]

No prob. Don't know if you use Bing Cashback but I found a new Jensen on Ebay for around $45 plus a few bucks for shipping and used Bing to get 8% cashback.

Here's the listing I bought from. No affiliation.
http://cgi.ebay.com/CABLE-TV-GROUND-...item5885215b7a

BTW, he has best offer but I made 3 offers and they were all automatically rejected. My highest offer was $40 and at that point, I got more savings from using Buy It now with the cashback.

[hearingimpared]

Just to add to the above suggestions, I've had ground loop issues in the past that were resolved with better ICs all around. This is especially true of using a step-up transformer in the turntable path. Although this wasn't so much a ground loop hum it was a 60 cycle hum and I was able to eliminate it using MIT Shotgun S3s and with Joe Abrams' suggestion of twisting 8 twists into the pair really got rid of the hum.

[phipiper10]

I used this to solve the cabel hum

http://www.parts-express.com/pe/show...number=180-075