Without resorting to doing it outboard (via my external workstation/mixer) can the built in audio of the Mac pro monitor Digital or Analog audio in via Digital out, WHILE that port is in use by another program? Example: 1. Logic running using Optical Out for playback 2. Sound source from an external unit is using Digital or Analog (either one, doesn't matter. I can convert from optical to analog outside the tower) 3. Mac OS's internal audio mixer can monitor the input while playing from Logic (or any software, really). This is a "nice to have" feature, and will reduce my dependency a bit on my Alesis workstation, freeing up desk space.