I'm kinda late getting in on this, but I have a nearly identical system except for the source. (Arcam CD93 -> VTL 5.5 -> Krell KAV 2250 -> B&W N804.) I did try some older Macs, 2105's I think, in a biamped configuration. Just wasn't to my liking as the music wasn't quite as full. I should note that these amps sounded wonderful in my friend's room with DIY speakers. Anyway, I found that the new Classe CA 2200 was excellent in my system in my room (dedicated). In fact I preferred the sound to Manley Snappers. I preferred the Snappers to the Krell, however. FWIW, my reference live music is the jazz combos and local music in New Orleans. The Snappers do a better job of making the bass sound more live than the Krells or the Classe. Go figure. However, the Classe provides a very nice tonal richness and balance that was very pleasing to listen to even at low volumes. I did hear both of these amps in my own system for 4 days each. Hope this helps, but if you've already purchased the Krells, you've made a good decision. Good luck.