Thomas,
You could try this:
. to /etc/modprobe.d/snd-hda-intel.modprobe I added
options snd-hda-intel model=ACER
2. to /etc/modprobe.d/alsa-base I added
options snd-hda-intel model=ACER
3. to /etc/modules I added
options snd-hda-intel model=ACER
Let us know if this helps.
Gireesh.