The Bryston 4B provides plenty of power to the Magnepan 1.6QRs. I plan to upgrade to Magnepan 3.6Rs soon, and hope that the Bryston 4B will drive those well too.
Wow! You spent wisely and economically. $540 for barely broken in 1.6's? Outrageous. Be sure to biwire the Maggies, it truly improves the already good see-through quality and the dynamics too.