Hmmm, I also tried the BHA-1 with Arcam D33 and another DAC. The BHA-1 wasn't aggressive with the other DACs. Even my D2000 single ended from BHA-1 w/ BDA-2 was very tamed. No nasty treble that you get with lower rigs.
How do you guys find BDA-1/2 in comparison to NAD M51?
Not sure...could also be source material.