Hate to be bombarding the forum with topics, but I thought I'd share something with the group. I work in film doing sound, and my boss was telling me about using Star Quad cable for long cable runs and for anything that crosses power.
Here is the science behind it...
http://www.soundonsound.com/sound-advice/q-whats-special-about-star-quad-cableAnyhow, I built some star quad cable for use with preen to see how it affected the noise floor and something magical happened...all of my interference from USB disappeared! No more display motivated noises, no more hissing, it's all gone! Must have been RF interference from the computer which the cable eliminated. Just thought I'd share.
