Comment 20 for bug 218165

There is a solution to get stereo working (at least on 6920G i can confirm this works) here:
http://ubuntu-virginia.ubuntuforums.org/showthread.php?t=852295
Though, setting the model to acer-aspire seems unnecessary, model=acer works just as well.
You can then turn on/off the "tuba" by turning on/off the "headphone" switch, very weird yes, but thats how it behaves for me..
Muting "Front" mutes the laptop speakers (including the tuba) so you can get audio out through your attached speakers only.

What still doesn't work:
-Surround (connecting 5.1 speakers to the laptop)
-Microphone