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View Full Version : How do eliminate cable tv noise/hum


fbm211
04-26-2008, 11:43 AM
From my past experence with my audio/vid system I know that when I get my SDA-2b set I won next week and get everything out of the closet and hook it all up that as soon as I connect my TV audio out to my system Im going to get that low hum.I assume that my cable (tv) is NOT properly grounded.I also have a pair of Adcom GFA-565 monoblocks the do not have a common ground.(im going to strap the neg speaker terminals to the chassis) I was looking at a panamax that has a ground lug.Will that work to ground everything???

F1nut
04-28-2008, 04:10 AM
There's a bunch written about cable boxes and ground loop issues on the forum. I'm sure the search feature will turn up a few answers for you.

steveinaz
04-28-2008, 11:16 AM
Ground loop hum can be very difficult to cure, but it can be done. I recently developed one that oddly enough was NOT due to my satellite connection (always my first suspect). By disconnecting EVERYTHING, and hooking up 1 component at a time until the hum appeared; it turned out to be a mix of 2-prong AC corded equipment, and 3-prong. My Direct TV receiver and BluRay player are both the 2-prong variety. They both were introducing hum--even with everything plugged into the same power source.

There's probably a number of approaches I could have taken to cure this, but I chose to use a Toslink switch. Now the DTV receiver and BluRay are both on Toslink, and the hum is gone. I could have tried floating the ground on my amp, but I don't like the safety issues involved with this approach. A 3rd solution could be to buy a grounding box that grounds everything to a common reference, but this required more money, and attaching a wire to every chasis.

kuntasensei
04-28-2008, 06:43 PM
Grab yourself a ground loop isolator for your cable here (http://www.markertek.com/Product.asp?baseItem=JEN%2DVRD1FF&cat=VIDEOEQUIP&subcat=VIDPROCESS&prodClass=VIDEOHUM&mfg=Jensen+Transformers&search=0&off=). I have to use one of these to kill a ground loop with my cable that causes rolling lines on my projector, and it works like a charm. Passes all digital cable frequencies with no problems.