I'm using Atma-Sphere M60 II monoblocks with Quad ESL 63's, and need only half the output tubes in a medium-size room. Sound is much improved over a Pass Aleph 3, not too shabby itself. For info on your speakers, why not contact the Atma-Sphere designer: ralph@atma-sphere.com? I've found him very accessible and helpful. You can allow for some bias, but I'm sure he can be trusted on whether your speakers and his amps make a good match.
