[bobby @ Jun 8th 2007 2:00PM]

One of the things I have encountered many times in the audio world is when you have lets say, a laptop with a usb audio interface attached that must be plugged into an electrical outlet, and uses phantom power. If the laptop isn't plugged in, there isnt any problem, but if you plug it in, something happens that creates noise. I believe this is usually solved by shielding the cable at some point with lead, its this plastic thing you snap around the usb cable that is supposed to fix the problem. Another thing I have often heard is that you must always keep power cords perpendicular to audio cables, and that having dimmers on your light switches and having fans on the same circuit will also cause noise. I think that this problem is essentially when you have two devices plugged into different outlets or the same outlet and they have unshielded cables running between them. I can't say for certain that what happens in the world of audio happens in the world of cable, but i think it probably does.


Here is a link that may be explaining what I am talking about:
http://www.belden.com/pdfs/Techpprs/tpbroad.htm