McIntosh Guy Going Tubes? (Maybe?)

I don't have any experience with the Sabrinas nor with the specific components mentioned in the previous post but my takeaway from hearing difficult speakers driven with low powered SET amps/integrateds is the outcome depends on the musical content, loudness of the music and the size/shape of the listening room. Vocals, solo instrumentals, and small ensembles sound magnificent at moderate listening levels particularly in a near field arrangement. Complex content with a lot of musical transients, including lower octaves, sounded strained and wooly at higher listening levels. In the ideal world, one would've separate systems for different types/genres of content but that is not always possible. On paper, I would have expected putting a Ref6 in front of a Master Classic2 would be the best of both worlds.

@kalali - Actually, it was very surprising.  My room is fairly large (14' by 20' in the immediate area, and open to about 40' in the off axis in an open floor plan.  Listening position is about 12 feet from the speakers.  The room is fairly lively with hard wood floors, though tempered with an area rug in front of the speakers, plus cloth covered furniture and a couple of drapes next to the windows.  My listening ranged from both small and large jazz bands, as well as rock and symphonic works.  I was very concerned in my evaluation that all my very wide listening tastes were represented.

I truly was surprised at how well the SET amp handled everything.  As I said, bass was not quite as tight as with the solid state amp, but I only felt it was lacking in direct comparison.  I also played pretty loud (for me, anyway), registering an average of about 85 db at the listening position using an SPL meter.

I don't have a great deal of knowledge about electrical engineering, but after doing some searching with google it MAY be that judging speaker and amp match by looking at wattage might not be the whole story and that current delivery plays a significant role in matching.

Again, though, this is my experience, with my room and equipment, my taste in volume levels, and of course, my ears.  I'm just suggesting that the OP shouldn't write off a lower power tube amp, particularly with the Sabrinas, without direct evaluation.

I did exactly what you did and love it. The current 275 amps are smooth at all sound levels. I am using xr5 speakers and looking for another set to stack them for the size of my room.  System looks sharp, equipment is a good value play right now. Even if you don’t like it, it can be flipped quickly.  

The thing with the mc275 is you can listen to it at normal listening levels without any desire to crank it.  All the music is right there even at lower levels. great bass and lower mids, just a music lovers amp