Might be best to specify this in the OP, we don't have crystal balls that tell us what OS you're trying to run. Not sure why you're using 14.04 specifically? Ubuntu MATE 16.04 is a newer release, and it should support the audio chip OOB.I'm running Ubuntu 14.04 and it doesn't want to see the audio chip. I can manually install drivers.
Asking questions about PPC Macs on the PPC forum is never a problem.Can I just add to the chorus here - I absolutely hate it when people ask questions about PowerPC Macintoshes on the PowerPC Macintosh forum. It's a massive breach of etiquette.