If you don't get an answer on this contact Audio Classics and ask one of those guys. They will give you an honest answer without trying to make a sale. If you're not familiar with them, they are McIntosh heaven and move a ton of used and new Mac gear, mostly to Japan.
McIntosh MC-252 or MC-275 amp
I currently have a pair of the original Sonus Faber Amati Homage speakers. After owning everything from many fine speaker manufacturers, the Amatis are by far the best. I am currently powering them with a McIntosh MC-252 amp, and a Integra DHC-80.2 pre-amp. I am considering changing the amp to the new McIntosh MV-275 tube anniversary addition. Has anyone had a chance to compare the 2 amps? I have heard it won't make that much of a change if your pre-amp isn't also tube. Any thoughts?