Others say...

"Reduces hum, but badly distorts and attenuates vocals"
I bought this product to reduce hum between my TV / DVD player and stereo receiver that I use to play movie audio through my sound system. The two are connected with ~25' of shielded RCA cables. Though the Xitel did reduce ground loop hum, it attenuated the vocals of the movies I tested it with so badly that they were barely audible. The hum was much better than not hearing the vocals at all! This product clearly has significant design flaws. I am attempting to return it and would not purchase it again.

"It works!"
I built a media center for all of my music and movies, plugged it into my stereo receiver and the humming began. Along with the hum was a high pitched whistle.

I decided to give this ground loop isolator a shot at fixing my issue and I am glad that I did. It cut out the hum and whistle completely.

I've got two Bose bookshelf speakers and four ceiling speakers. The surround works great now! Buy it!

"this thing actually works like it says it will"
i never write reviews on products until now.plug it in and the humm is gone.i've got my pc hooked to my yamaha amp with 1000 watts of power and there is absolutely no humm.even cranked all the way up where it's shaking the dust off the ceiling fan.and in between songs there is complete silence.no humm what so ever.sound quality is not sacraficed either and i am extremely picky about that.well worth the price.wish i would have found this product sooner.buy buy buy.

""Great" no buzz at all even with volume all the way up"
Had a big problem with buzzing when playing mp3s on my computer through my stereo tried one from radio shack got rid of the buzz, but lowered and muffled the sound.
This one gave me great clear sound with no buzz.

"No more hum!"
If you have a powerful, amplified subwoofer and have tried everything in the manual to get rid of the hum (but failed), this is for you. It is very simple to use. Does it affect sound quality? I haven't performed any listening tests but my guess is no, it does not. Oh, I should mention that I'm using this (and another), in a home audio system. I know car systems can have similar problems with alternator whine but I don't know how well it would work in those applications.