[musicbuff]

I've researched Bryston BDA 1 and 2 and NAD M 51 DAC's. After having bought a new pair of headphones and a new HP amp (Sennheiser HDVA 600 and Sennheiser HD 800) I want a DAC that will bring out the best in them and my speakers (Monitor Audio RX6's). Is there any great differences between the Bryston BDA 1 and 2 other than an improvement through asynchronous USB? If I were to get a BDA 1 would it be best to listen through optical (I have that on my computer) and if so how good would my music sound? Or should I just get the BDA 2 and go with the new improved USB. Most of my music is on my computer (Dell XPS through JRiver Media Center). I read in one review that Bryston is a better fit with Audeze HP's due to highs being a bit aggressive when paired with the "already revealing" Sennheiser HD 800. I experienced a bit of excessive sibilance and treble graininess with the HD 800's before I connected them balanced. Now treble harshness and graininess is minimal and only present when the original recording was made that way. Sound stage is very important to me but it's been reported that the M 51 is not as good with this and suffers from some bass bloat. Those of you familiar with these 3 DAC's please give insight as to their strong and weak points with my (or any) setup. And to save every ones time I'm not interested in any other DAC's so please don't recommend any others. Thanks.