Review on PAC SNI 135 Ground Loop Isolator by Steve Yatnalkar

I bought this product to isolate the noise generated by the headphone jack on my work PC. Unfortunately, the PAC was found to be unsuitable for this application. Other listings for the same product typically say "for 3.5mm applications", while this listing specifically says "between your receiver's AUX input and your portable music player". I can confirm that the latter is correct and that it doesn't work with headphones. Headphones and audio device, PAC eliminates unwanted noise. However, I have had the same experience as with the "Raydock" (from this one) - the volume of the music is reduced by at least half. Turning up the volume doesn't restore the output levels and the result gets muddy. For testing, I used 2 headphones (small in-ear headphones, large closed phones) and 3 audio devices (work PC, home laptop, portable MP3 player). I also used an f-to-f adapter and auxiliary line so I could try the PAC both ways. Each combination gave the same result. I also tested the PAC between my MP3 player and my laptop's line-in. There was no half volume problem in this app. One thing to note here is that the direction you plug the PAC in is important. When I used a computer to monitor input levels, I saw the following: * MP3 plugged directly into laptop: 90% peak * MP3 plugged into 'Out' PAC: 70% peak * MP3 plugged into 'Input' PAC: 100% peak not sure wondered if that would even work, but thought it might be worth a try. I hope this will be helpful to someone who feels the same way.