Cable TV causing system ground problems!

After responding to another thread about powerline products. ..I wanted to post what you might call a warning...or at least a "heads-up". Cable they for TV or cable internet..or FM, can cause real problems for your stereo. The ground on cable can have DC and other problems..that if connected to your system through interconnects from unit to unit, or to the AC can cause you to go searching for a cure. The real cure is to keep cable feeds out of your system and your systems AC.
I have also had this problem several times in the past. Power conditioners, filters, cords, and such will have absolutel no effect on this problem. For a cheap fix, you can go to RadioShack and get a "ground loop isolator". This is basically as set of cheap RCA's witht he isolator on them. It works 100%. If you want t spend the extra money you ca get a MAGIC. For details on the MAGIC, as well as info on eliminating these, you can go to Michael Elliot's website,, and go to the hums and buzzes section. He has links to retailers of the high end tiems. After years of struggling with this problem via expensive audiophile/videaphile fixes, and even disco'ing the cable when listening to music, a friend brought over the $8 Radio Shac fix and it worked like a charm. Hope this helps.
It does, and you're right. I am not a big TV fan..and am a big music I have just kept the two seperate.
Whatjd, Are you saying that the cable from my external FM antenna to my tuner can cause some sort of problem? I haven't noticed any, even when my tuner is on while playing other sources. I also don't have any problem with cable TV of which I'm unaware. Appreciate your input.
I agree that the best solution is to keep CATV separate, but for a variety of real world reasons mine isn't. But I've had excellent results in effectively eliminating hum/buzz -- and other problems -- in my audio system using the ISOMAX VR-1FF isolation transformer from Jensen Transformers ( It's specifically designed to squelch CATV ground loop problems at the source and this piece is more effective than the Radio Shack piece by an order of magnitude. It costs $49, but is well worth it. CATV connections can cause all sorts of complex ground loop & even feedback problems. This item is a simple & effective fix.
Sfbaydude: I was speaking of cable TV/internet/FM..but not the 75 ohm coax lead from an external FM antenna. It is good that your cable TV input is not causing any concerns with your hi-fi system. Cable TV need not have ground concerns...but often does..and if it does, and your TV is connected in some way to your audio will cause sound quality concerns. With anyone, the easiest way is to find out is just disconnect the cable (and all TV related items/cables) from you audio system..and listen. If your system sounds better with the cable/TV components disconnected..then there is likely a cable TV-ground concern.
Whatdj After reading this thread I checked disconnecting the video part of my hibrid system (TV, VCR CATV) from my HTS-2000 and their interconnects to my preamp/processor and found a much cleaner background and definition in the audio presentation. Worth the try!!!! Currently I'm keeping out of the HTS the AC feed for the video stuff. That kept most of it but the interconnects are bringing some of it back. The TV and VCR have just two prong plugs and I'm going to try a ground connection from their chassis to the grounding rod to see if I can kick it out completely. What do you think?
I think some of the suggestions above are worth the try.. It seems that the ground form the Cable TV feed is usually the concern...usually DC voltage on the Cable ground. If you look at the info that comes with the Monster power strip the model HTS-2000., they give some excellent information on the subject... It appears that Mr. Marsh and Monster are very aware that Cable TV presents real problems for audio systems...
Whatjd, Thanks as always.
Sometimes you get a ground loop when you have a dedicated ground for your system and your 75 ohm antenna or cable is attached to another ground. The easiest and cheapest thing to do is to get two 75 ohm to 300 ohm comverters and attach them back to back, use a voltmeter to test the continuity of the threaded shield, if it breaks the continuity you will eliminate the ground difference, which can be either a big or a small improvement depending on your particular ground problem.
I recently solved the problem with a $12 Holland Electronic ground loop isolator from a local A/V shop. Solved the problem. A friend of mine suggested a homemade 75-300-75ohm resister series to do the same thing (see post above). I still kick myself for not visiting Radio Shack and saving $4 bucks. I could almost by a used CD. Have fun! Kurt