Under windows XP I had the system configured for "digital output only" its a checkbox on the mixer under the "advanced" menu. I have a set of cambridge soundworks digital speakers connected to my SB Live via the SPDIF out.
How do I instruct the sound driver to enable this under linux? It seems as if the card is properly configured and working, and though I haven't tried it, I'd guess the analog output has sound on it, but nothing out the digital.