08-24-13: Cerrot
I think anything other than an spdif out via a sound card is a LARGE reduction in sound quality. Why would we go through the abomination of converting a usb signal into high end audio when you can have sound card doing it natively?
I am going through this mental debate right now as I plan my CAPS server build. My practical side says why not just get the ASUS Xonar soundcard and use its SPDIF straight into my DAC instead of having to get USB converter in between. As Doggiehowser has pointed out there appears to be come benefit to using the USB then a converter to get rid of noise, jitter, etc. That being said, I am going to have to try out both ways to see which is better.