The Pass X151.5, aside from great sound, has more power than you might think. A British hi fi mag about 2-3 years ago tested it and found that at 8 ohms it clipped at 280 watts, IIRC, and at 4 ohms 370 watts, again IIRC. I had no trouble driving my Magnepan 3.6's with it using a passive preamp.
