USB Audio on Raspberry Pi

One thing that I forgot to mention in my diagram in previous post was that I was planning on using USB audio as a way to get the sound out of the Pi, as the on board analog audio is pretty bad. I might modify the diagram...

In order to set the USB audio device to be the default audio device I did as suggested here: http://www.raspberrypi.org/phpBB3/viewtopic.php?t=20866 and modified the following line in /etc/modprobe.d/alsa-base.conf

#options snd-usb-audio index=-2
options snd_bcm2835=-2

After changing that and rebooting if you do "cat /proc/asound/modules" you get 

0 snd_usb_audio
1 snd_bcm2835

showing that the USB audio sound card is indeed the default. That was all I needed to get the USB audio sound card to work correctly.