5.1 Surround Headphones

[L33t Masta]

I have a set of Turtlebeach AK-R8 5.1 surround sound headphones. Thing is, the sound card that came with them is utter trash. I only use it on my laptop because I have an X-FI in my PC now. Thing is I want to know if I can use them on the desktop without the need for the USB soundcard. They have an odd connector that looks like this:

Any idea if I can use these without the sound card?