The Parasound 1600 HDCD DAC that Sfar mentioned is excellent value, although the CEC DX51 (which does not have HDCD, however) is better quality electronics and sound and should start appearing on the second-hand at discount market since CEC just released a Mk. 11 version (unless the owners decide to upgrade their old ones). Both have good power supplies, excellent input/output flexibility, and very good sound--with the CEC about 20% better than the Parasound. Parasound discontinued it's low-cost DAC series a few years back and you can find plenty of 1600's second-hand for about $400-500. I would not pay more than $700-800 for a used DX51. This is slightly more than your original price range, but worth it when considering the difference in quality between this and what is available for $300.00 used. You will probably not be upgrading this part of your system for a while with these units. CAVEAT: Do not buy a Parasound DAC "new" from a store as they are probably "second-hand" at a "new" price.