which output setting sounds best?

Windows Audio Session API (WASAPI) is the Windows-resident interface provided in Vista and later OS versions that supports exclusive bit-streaming to a specified device in native resolutions up to 24/96 via USB 2.0.

There are likey other issues with Vista 64 that may lead you to want an upgrade to Windows 7. But WASAPI should be resident and if so,

This is definitely the selection of choice - unless your DAC supports higher resolutions, e.g. 24/192 or otherwise directs you to another driver.

Media Center includes WASAPI as a standard option. Run WASAPI in Event Mode if possible (In some cases you may need to increase buffer size from the default of 50ms).
This allows your DAC to impose control of packet timing and size.

BTW, Media Center's core algorithms take full advantage of 64-bit mode when available.

Good Luck.

Most of the posters are correct, but I take exception to Cerrot's position. Upon inspection of your virtual systems, I can see that in your eyes and budget, the HRT may seem "indecent", but to someone just breaking into PC Audio, it's a real drag to hear that their chosen device is pretty much worthless. The HRT can certainly be bested by other products, but it has been well-reviewed at its price point and would be a perfect place to start for someone just testing the waters with PC Audio.

Saying what you did without offering advice is akin to telling a kid you won't teach him how to swing because he's "a little short for baseball". It's not about the gear, it's about enjoying the hobby along with enjoying the music.

Evan

Evan, I'm just being honest. The gear mentioned is not transparent enough for the OP to be able to discern any difference between the settings he is asking.

You know, its like telling your friend that he should upgrade from the $20 hdmi cable to the $1,500 HDMI cable but the TV is 480i. Get it? Lets first teach people how to listen and what to listen for before we allow them to get caught up in minutia. And, maybe the baseball thing is bad analysis but if I had a son (or friend) who was real skinny and fragile and wanted to be a linebacker, someone should let him know he may be better akin to something else. Get it? HONESTY.

I won't pursue it further, but your honesty really doesn't help the OP. He's already purchased the gear, and wants a little advice on setup.

Don't presume that your sage advice on how to listen and what to listen for is what's necessary in every instance. My only point was that you weren't offering any real help, just planting a seed of doubt and disgust in the OP's mind that he may have made a bad choice with his hard-earned dollars.

I hope you never need advice on a piece of gear; I'm sure someone with a much more expensive system will be waiting for an opportunity to tell you it's garbage and you shouldn't worry about the minutia.

Ekwisenek, It doesn't matter how much the gear costs - what matters is HOW IT SOUNDS. I appreciate the recommendations I receive on the forum. We are all in different places financially and all have different budgets. The idea is to get the best within your means.