I disagree with the tube preamp idea...In my opinion, you match Bryston pre amp to Bryston amp for best results. In regards to impedance matching, among other things.
Like I said in an earlier post, I auditioned these Phase Tech speakers, and they were dull and muffled. Not sure why, but they were. It would have been easy to blame the Bryston equipment, but guess what? It wasn't the Bryston equipment. It was those wretched speakers! My lower-line JBLs are the opposite (if maybe a little bright,) but they sound good on all genres of music and many different types of recordings. Believe me when I say I've played some real lousy recordings through my system! Even the worst recordings sound at least somewhat listenable.