Best soundcard if have outboard DAC


Looking to use a PC as a transport. Will have an outboard DAC feeding a preamp. I want the soundcard to feed the DAC with a digital signal. I don't want the PC/soundcard doing any processing, only sending the untainted digital signal to the DAC. Sound is important, not cost. What is the best soundcard for this? Also, what is best: AES/toslink/USB?
bigamp
Are all digital outs (USB or otherwise) thet produce 24bit the same quality? Would something like the new Creative X-Fi give me a better quality digital out then one of the externals that you recommended, or all they all the same?

Sorry, don't know much about things at this level...
Try both connections to the outboard reciever and let your ears determine what sounds best to you! It still does not matter what you use to feed the bits to the DAC. USB or sound card will not matter in the digital realm with 44.1khz output. Most Creative cards will not output 44.1 SPDIF. The Burr Brown DAC is a excellent D/A converter. Bits is Bits no matter what you use. The DAC is where the sound quality comes into play.
A lot of computer devices output at 48 kHz, not the native 44.1 kHz for ripped CDs. I know the waveterminal outputs 44.1. Bits are bits, but certain device may be more prone to jitter problems if they have lousy cheapo clocks in them.
"Bits is Bits no matter what you use."
I'm a little confused by this. Is jitter no longer an issue when the data source is a PC hard drive?
How do you guys bypass the Kmixer in Windows?? I use both my on board Nvidia sound card (optical out) as well as a Maudio 2496 (coax).

Unless I play DD or DTS, I am always able to change the volume with Windows meaning that the signal gets converted somehow. I use digital out but since Windows acts like a preamp I'm really not getting any benefit from using a external dac.

I'm using foobar 2k for music playback.

Any help would be greatly appreciated.

thanks