Computer output to DAC, which route?

I have a custom desktop PC with a very good motherboard. I've been using the motherboard COAX into a Channel Islands DAC (VDA-2) for some time now. BUT!! Recently I purchased a $20 (yes, a mere $20!!) USB to SPDIF to compare performance. Wow was I surprised. That $20 USB/SPDIF converter blew the doors off the motherboard in terms of overall sound quality. I don't have an explanation. I'm using a TOSLINK with the USB/SPDIF since it does not have a COAX out. Not exactly apples and apples and a bit broad brush but the overall result strongly suggest that most anything beats motherboard audio outputs. And for $20 you can afford this upgrade even if your results are less stellar.
Cheers!
Morten

The explanation is lower jitter. The more you spend on the USB converter, the better the SQ.

Read the reviews.

The jitter of the clock in all digital systems is the most important thing to optimize. Dont scrimp on this because there is nothing downstream that will fix it. Not even reclocking in the DAC.

Steve N.
Empirical Audio

Tortugaranger: What $20 converter did you get?

Unless your computer is in the same room with your stereo (why??) then avoid using the computer as a source component. Stream the music over your home network instead, so some device that outputs SPDIF to your DAC.

I use the Squeezebox system myself and love it, but if you insist on iTunes, you do have some options. The Apple Airport Express will do exactly this - you can stream your iTunes collection to the AE, and the AE device will output a toslink signal to your DAC. Note that the AE requires a special "mini" toslink connector.

Also, if you insist on using your computer directly as an audio source, do not use the onboard SPDIF output, or even a USB device. Use only a Firewire device!

Firewire supports isochronous data transfers - critical to a clocked data stream like SPDIF. USB does not support this!