That would explain the apparent difference.
After diiging out another SB Live, I can vetrify what baisaz has stated. The SB Live boes indeed contain an AC'97 codec labeled EMU-101K1.
However, since there are obvious improvements using this card (and not all AC'97 implementations are equal) I'll stand by my original statement that the SB Live is a big improvement over the rear sound outputs of a Powermac.

A quick question. The Audigy card I have uses the CA0106 DAT (which isn't supported). Which Audigy's (and which chiosets) are supported?

[ Edited by Jim on 2010/10/30 0:13 ]