long story short... i use the 20" Aluminum iMac and the ALSA support for RealTek 889A is spotty at best.
since the day i first got this thing rolling i've been manually specifying a model by creating a file in /etc/modprobe.d called 'sound'
inside this file i insert the following text to specify the model definition 'mbp3' (which, is a MacBook Pro 885...but it's the only model i've found that works)
alias snd-card-0 snd-hda-intel
alias sound-slot-0 snd-hda-intel
options snd-hda-intel model=mbp3
i know ALSA has made a lot of changes recently and i would like to find out where they keep the model definition documentation for snd-hda-intel
so i can try some of the new model definitions to see if i can find one that works better.