I am delighted to own the MC402 and the C2200 pre-amp combo. They really make my Meadowlark Blue Heron II's sing. I've had Pass Labs,Plinius, and several other high end amp, pre-amp combos. This is the most coherent, musical, accurate sound I've ever had. Haven't heard the MA6900, but this current line of Mcintosh equipment is a lot of quality sound for the money. Good luck.
Joe
Joe