Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
what's "inexpensive"? anything in the same price range won't be enough of an improvement to notice. spend that money on room treatment or a good mic for a noticeable improvement.
 
...The point isn't to improve upon the DACs in the mbox but to use the spdif to gain another couple of channels... Any suggestions?
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.