Interesting thoughts, facts and feedback, gents. Thanks.

A bit about my setup. My amps mate with a C1100 and play into a pair of Tannoy Kensington GR speakers (93db sensitivity). Sources are generally a Rega P10 through a ModWright PH 150, a Mytek Brooklyn Bridge DAC, and a Jay's Audio CDT2-MK2. I listen to pretty much every kind of music (sometimes with volume cranked way beyond "piss off the wife" levels) and I can tell you the bass from the MC75s lacks for nothing to my ears. In fact, interestingly, I find it deeper and tighter than with the mono-blocked 275s. Along with the highs and mids, the bass from the 75s is highly musical and nuanced, and emerges from an incredibly quiet background in a manner that I can only describe as effortless. I find the bass from the two 275s, while excellent, to be a bit less organic - it seems to have to "try" a little harder.

Now, it occurs to me that what I have not done is an A/B comparison between the two 75s and a single 275 - I wonder if that exercise would bring me full circle to the conclusion that one 275 is better than two (not an uncommon view among us!)

Fun discussion...

Being in the group that found the MC75s the best, followed by a single MC275, a pair of MC275s in a bi-amp configuration and the pair of MC275s as monoblock amps to be the least good, my surmise is it not only the 'stronger' power supply in the MC75s helping out, but having only a single pair of power tubes per channel also being important. For whatever reason, to my ears, in both tube & solid-state amps, those with the fewest power devices generally sound the best.

There seems to be lots of love for the MC75, why did they stop making them?
I suspect they will reintroduce it at some point, maybe an anniversary addition.
Curious...would McIntosh ever build a MC150, essentially a 275 designed as a mono block only?

Having ABed a pair of 75's to a single 275, to my ears the mono blocks were a huge improvement.

I have switched the 75's and 275 around in my system and while the bass was more defined, too much more was lost. Did toy with the idea of four 75's but upgraded to the 1100 pre instead. At some point, going to pull out the 275 all-together to hear what it really brings to the table.

It is my understanding that the discontinuation of the 75's was very abrupt and dealers were unable to make a "last ha-raw" order.

Looking to join the club. I have a MC275 mk VI. [emoji3] Currently, using my MAC4100 has a preamp. Enjoy it every day.

After 5 years or so my OEM tubes started to fail. Ever since i bought my Ver 6 as new I’ve never changed the tubes. I changed them recently as the sound was stronger in one channel. I changed the KT88s to golden lions but sadly i did not notice much in terms of sound. It not worse than the stock tubes but neither is it better. So the only issue for me now is longetivity if the GLs will last as long as the McIntosh tubes.