Battling Cable Box Hum

[Robert-The-Rambler]

For years I'v been putting up with the annoying low groan of hum caused by my incoming cable wire. For the past few years I simply gave up on being able to connect my digital cable box to my receiver that has high powered dj amps connected to the preouts. I do love the Behringer EP2500. Today I surfed the web and came up with a good solution that replaces my just disconnect the cable wire method/ give up method. I found the real solution at Radioshack. Here is a link. The miracle worker is called a ground loop isolator.

http://www.radioshack.com/product/in...entPage=search

The sweet thing is that it only cost $16.99. I'd been complaining all the time and even questioning if going with separate analog amps was even worth it any more. Hell, there was audible hum even when I did disconnect the cable wire from the box. It just wasn't quite enough to ruin the audio experience. Without have ground loop isolators the noise was so bad it could be heard almost as loud as what you were trying to listen to. What is a ground loop isolator? They explain it better than I can here.
Just scroll down the page for the full skinny.
http://www.21best.com/21_best/electr...for_sale_.html

Anyhow, other than lousy cable grounding, a ground loop can be cause by having various audio devices connected to various sockets. Hum is the result of the ground loop between the various sockets/ power lines trying to balance the voltages. In my case I have a double whammy. I have lousy cable ground and amps and other devices connected on various sockets/ power lines. My solution is that I connected 4 ground loop isolators to the preouts of my Pioneer VSX-1016TSV . It is so simple. Just connect your ground loop isolator directly to the specified pair of preouts. Then via a female to female rca coupler just connect the cable you were already using to the isolator and your amps input. It just connects in between your source and your amp. It is that easy. I repeated that process 4 times and I was able to watch football with wonderful Dolby Digitalness and even crank the wierd sounds of Soundscapes on one of the digital music channels. No hum at all safe volume levels.

Anyhow, the hum is gone, and the signal is preety damn well preserved. These isolators do not hack and slash your signal dramatically. The "loss" is almost impossible to hear with my setup. So if you have a hum problem why not try such a low cost solution.

I just ordered a ground isolator to connect directly to my cable wire, too. It is anly 48 dollars from Axiom. http://axiomaudio.com/groundisolator.html I am hoping that gets rid of whatever might be left.

I still have hum a bit on my HD-DVDs via 5.1 analog inputs. Toshiba does not seem to be providing us with enough output via those 5.1 outputs to reach a comfortable level before what hum is left kicks in at ridiculous volume levels on my receivers digital volume control. When you need to get to above -10 through 0 to hear a movie at a volume where other sources are cranking at -30 to -25 obviously there is a bit of a problem. You can hear the hum kick in as you get up to -15 or so and by -5 it is loud.

Now I want even more power.

P.S Thanks Tony3D for starting this thread. Crown Xti Hum It inspired me to solve my humdinger of a problem.

[markw]

Take two 75 to 300 ohm baluns and connect them back to back at the 300 ohm terminals. This will break the ground connection between the incoming cable and the cable box itself and generally cures the hum.

http://cgi.ebay.com/75-300-ohm-outdo...QQcmdZViewItem