I have been using the MA2275 for about a month now. This is my first setup that is all tubes; I really enjoy it and now understand why people enjoy tubes.
In swapping emails with Ron Cornilius of McIntosh, he stated, "The MA2275 has a very clear sound with low distortion."; I agree with this. I was previously using a kW500, which is also "very clear with low distortion"; In my system I found the Mac to surpass the kW in clarity, being the most revealing amp I have owned and I certainly don't mean that in a bad sense.
I should pause to mention that the first 9 days of owning it (I purchased it used) I wasn't totally sold, it had a great midrange but it was very veiled. After 9 days I took the only after market power cord I own, a Virtual Dynamics David, that was on my CDP, and moved it to the Mac and this made a huge difference, totally removing the veil. (I don't know if my stock PC has issues or not.)
Anyway, this is by far the most 3 dimensional system I have owned allowing me to hear into the soundstage like I have not experienced in my house before, to the point of hearing things in recordings that I haven't acknowledged before and/or hearing rendered as such.
My speakers, B&W 802D's, while they like power, mate very well with this amp, that said, I can run the amp out of steam. I use the 4 ohm taps per McIntosh's recommendations for my speakers.
The bass will go surprisingly deep, but differently than when using the kW; the kW had deeper bass at a constant level, but the Mac seems to reproduce real low level stuff in a way I don't recall with the kW. The midrange and upper end are exceptional, to me.