Windows 7 Compatiable
 

Right now I have penciled in a Asus Xonar Essence STX but I am not sure if I need that good of a sound card. The only reason I had chosen that card is because it had a TOS-Link/Optical output and was compatible with Windows 7. I noticed that the Asus Xonar DX 7.1 card also had a TOS-Link/Optical output but said it was not compatible with Win7. But when I looked at at the driver download centre
ASUS - Sound & Multimedia Devices- ASUS Xonar DX
it had a driver for Win7.

So I guess I am asking if the Xonar DX 7.1 is compatible with Win7?
Also I will be using this for gaming (I am not a audiophile I do like good sound but not that good) and I have an Astro A40 headset I will be using for this rig, no speakers.

I had a Xonar DX, good sounding card. It works just fine in Windows 7.

The only thing I recall is that it needs an adapter plugged in to have a TOSlink output, but I don't remember which port it goes in. You should check to see that it won't interfere with your headset being plugged in.

I use the Xonar DX right now. Works fine in Windows 7. Yeah, it came with an adapter you plug into the mic input on the card to use the TOSlink. You can straight up use a mini-toslink to toslink cable if you don't want to use the adapter, it fits in the same slot.

If your motherboard has the TOSlink connector already, you don't need a soundcard. If you only plan on using TOSlink, then I'd buy the cheapest possibler soundcard that has one since all that output does is pass through so there is no sound quality difference between low end and high end soundcards when using that output.