Why not a run high quality USB cable

Yes, USB 2.0 spec is 15 feet. You may get away with longer with slower devices. Also, you just need a cable that meets spec - $20 or so. The only way a USB can "change the sound" is if somehow bits are uniformly changed to alter the sound in a uniform way. Or some bits get flipped and some samples are corrupt and substituted in the player with previous good samples. It's quite easy to determine if your cable is corrupting data. Just connect an external USB drive to your computer and cable and copy files with some sort of data verification (checksums, zip file intergrity test etc) and see if any files get corrupted compared to the source when reading it back. It's very unlikely you'll see and difference between a $20 cable and a $200 "audiophile" USB cable.

There are active USB extension cables like that one that measures 32ft:

http://www.amazon.com/Meters-Active-Extension-Repeater-Female/dp/B002VG39BI/ref=sr_1_14?s=electronics&ie=UTF8&qid=1288731775&sr=1-14

^^^^ That should make it easier for people who don't want to run a cable across the floor from computer "front end" to DAC in rack and people with big rooms. Nice price too!

Most active USB extensions dont work for audio streaming. I would recommend trying Opticis.

Steve N.
Empirical Audio

Steve,
Would it work with USB to Toslink Converter? My friend wants to run 30' of cheap IC from the sound card to receiver while his receiver has Toslink input. 30' of USB extension + converter + 3' glass Toslink is perhaps better?