Hey Jason
It's an older 4B Bryston (two channel/mono block - switchable). I have it hooked to the M80's via the receiver's preouts.
He told me of a cool way to listen to CD's, you hook the amp straight to the player. The amp has two hidden dials that control volume - 0 to 100%. Setting it to 0 I started the cd and slowly turned up the volume. This gave me my first "WOW" moment with my 80's. And that was only between 1/3 and 1/2 on the volume!
He has several 4B's and some 3B's that he might consider selling, interested?
