It appears that my jubulations were a tad premature.  The sound card lets you have six channels, but they are just three groups of the same stereo pair.  Darn.  Guess I will have to return the sbmp3 and get a hammerfall.  Does anyone know if the hammerfall's adat optical can be understood by a 5.1 amplifier, or do I need to actually get an adat too?

The good side is I still have a couple days to do ac3 testing before returning the unit.