I would reccommend the Xitel Pro Hifi Link www.xitel.com. The benefit of this device is that you bypass your soundcard by using a USB connection. Then you have 2 options with the Hifi Link: YOu can use it to do the DAC or you can hook it up to a receiver with either an optical or coaxial connection and let your receivers DAC's do the conversion.
When you use a sound card in the computer to process the DAC you are subject to all the electromagnetic interference inside the computer. Moving the conversion outside of the "box" to your receiver provides you with a pure digital connection with no interference.
as an addded bonus, the Pro Hi-fi link comes with 30 feet of optical, coaxial and analog RCA cables, plus the USB cable and the hifi link istelf all for $99.
Check it out, mine works great, the only con is that you have to diable your soundcard (through windows control panel) to activate the hifi link. This only takes 2 seconds and you can change back to your soundcard whenever you want.
