The DAC/DSP board in the Bryston DP3 is indeed not the best solution, in my opinion. It is an off-the-shelf DAC/DSP/Processing board made by Momentum Data Systems. While it is extremely convenient for a company like Bryston to use as the basis for their processor, I believe it's compromised when compared to dedicated DAC systems. The Bryston BDA-3 DAC is significantly superior over this. The Momentum DSP board is meant as a pretty good all-in-one DSP/DAC solution for a front end to a processor.
DACs for older gear
A seemingly knowledgeable poster at the Bryston thread of AudioAficionado suggested that the DAC process of my Bryston SP3 is older technology and that my Oppo 205 has a better DAC that I might use. The SP3 has a number of features that make it flexible, including lots of balanced ports so I'm reluctant to discard it. It appears as though DACs that accept HDMI input that I might use in front of the SP3 are rare -- I've read the licensing fees for HDMI are very expensive. Is there an obvious solution? Other than for the 205 and SP3, I've moved to the Ayre 5X series for stereo.