I will offer another solution - sell the BP25DA and get a used BDA-1. You'll pick up more inputs, possibly get a dedicated power supply (maybe the BP25DA had one for its digital side- don't know) and you will upgrade to dual DAC chips versus the single chip that's is in your preamp. The sound should be the "same" given the same crystal chips are used in both but better given the BDA-1 is really a fully separated 2 channel DAC. I would suspect that the costs could just be a wash, maybe a little out of pocket.
To me it makes more sense...