I have an ASRock 890FX Delux4 motherboard that I was having a damned of a time getting the audio to work on in Ubuntu 12.10.
The solution turned out to be that pulseaudio didn't have the device selected as the output, but that was completely not discoverable via the UI.
I had to install an extra program to tell pulse to use an output channel other then what it was using by default.
sudo apt-get install pavucontrol
This was the ticket I needed, selected the correct output for sound and viola! magic.