I shot them out against Mcintosh MC501s. Clasee CA-M400 sounds a bit roller off on the top end. The new ones the CA-M600s have extended highs. Fine amps both. I shot the new Classe out against the new Mcintosh MC452 stereo amps . Classe CA-M600 was better but not by much. The MC452 is a bargain at 7500.00 I heard the CA-M600 at 5 different locations each time with the B&W N802 Diamond and additionally Sonus Faber's 45k speakers at one location.