USB Cable Ridge Street Audio/Synergistic Research

I too am very curious if a better quality USB cable will make an improvement since i am in the process of downloading my entire collection to an external hardrive. That being said, is it just going from your computer to an external DAC that will make a difference? The only USB cable i am using is going from my external hardrive into my computer and then i have a separate non USB cable(looks like a computer cable similar to one that goes to your monitor but not sure of the type) going into my outboard breakout box of my soundcard which has an internal DAC. From there i go out of the soundcard breakout box via 1/4" ends and then into my tube preamp via RCA ends. At this point i am very pleased with the results i am hearing but if a superior USB cable going from the external drive into my computer will improve sonics then i am all ears. But i too have previously read that they don't make a difference so i am very interested in hearing more about this matter.