Are most DAC's compatible w computers?


I have an SPDIF output that comes directly off my harddrive on my windows xp based computer. I also use windows media. i was thinking about inputing this into a tube DAC to both increase the sound quality and flexibility in my system configuration.
I wanted something fairly inexpensive... I would like to spend $300 or less and have been looking at Cal Labs Sigma II.

Is this straightforward no brainer kind of stuff or is there something that I'm not thinking of... like compatiblity issues?

Thanks,
Doug
128x128lokie
Thanks, Ckorody. You are right that a USB DAC would be a simpler path than adding a DAC via the Waveterminal. Are there any other USB DAC's worth considering besides the Apogee (without breaking the bank)? Thanks,
I just figured out that I can get lots of great radio through my computer as well. I can now sell my changer and tuner if I want. I am thinking about putting my money towards a really good DAC since my computer is turning out to be the heart of my system. Now that I have ripped my 500 cd's to computer, and have all the album artwork loaded as well, I can't believe I didn't do this sooner. I am rediscovering my music collection and listening to stuff I haven't listened to for years. It would not surpise me if we begin to see a lot of USB DAC's on the market very soon.
Hi guys -

I agree this is the future - I keep flogging the USB DAC idea - powered by iTunes and 6 billion downloads a year versus a declining CD market it seems a no brainer at many market levels...

I too have had excellent results with the Waveterminal - so clean and simple and no power supply. Sorry about the misquote on the Rankin products, I guess you would have to consider him a possible USB DAC - not too much else out there that I am aware of but you should check out
http://www.empiricalaudio.com

The gentlemen is a former Intel engineer and a big time modder who is one of the first people I ever corresponded with about the USB direct issue

Great thread - kudos to all
This is the thread for which I've been looking. GREAT info. I've decided that hard drive to DAC to stereo is the wave of the future and it's here now.