I have my Asus GT220 working!
Instructions are here:
http://xbmc.org/wiki/?title=HOW-TO_s..._Begin.2FNotes
in my case when looking for the card:
$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC883 Analog [ALC883 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: ALC883 Digital [ALC883 Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
Subdevices: 1/1
Subdevice #0: subdevice #0
I note that my motherboard's in built sound card is 0 so to test I used:
speaker-test -Dplughw:1,3 -c2
the '1' means card 1 the '3' means device 3 and the '2' means 2 channels i.e. stereo
you can change the '2' to '6' to try 5.1 audio and '8' to try 7.1 audio
Hope this helps,
Cheers
Doogs