Re http://lalists.stanford.edu/laa/2010/04/0017.html and finding one of these http://www.soundonsound.com/sos/1996_articles/may96/yamahadb50xg.html ... Investigating further, I find there are very few PCI cards with the Waveterminal header, however, the Dynex 5.1 does have this header
http://store.high-techoffice.com/dy5pcisocamo.html ($6.00)

And this card supposedly works well in linux
http://alsa.opensrc.org/index.php/Ice1724#Dynex_DX-SC51

Dynex DX-SC51

Linux seems to really like this card. AC3 and DTS passthrough out the optical jack works perfectly, and I can dump stereo audio into it no problem. I get full 5.1 sound out of the analog jacks too. Haven't tried capture or the headphone jack, mainly because I bought this card specifically for an HTPC.

Which isn't bad, even if you don't attach a $20.00 DB50XG card....  $26.00 is a pretty good price for a Yamaha TG33 with an spdif output, don't you think?

Niels
http://nielsmayer.com