The left audio channel on my work computer crackled badly. Ubuntu 8.04. Soundcard info from lspci:

00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)

Remove snd_hda_intel:

$ sudo modprobe -r snd_hda_intel
FATAL: Module snd_hda_intel is in use.

$ sudo lsof /dev/snd/* | grep mixer
COMMAND    PID  USER   FD   TYPE DEVICE SIZE  NODE NAME
mixer_app 9593 carlo   20u   CHR  116,0      11357 /dev/snd/controlC0

$ kill -9 (pid of mixer_app)

The fix: load with position_fix and model parameters.

$ sudo modprobe snd-hda-intel position_fix=1 model=3stack

Then use alsamixer to turn up and unmute main/pcm/etc.