McIntosh Guy Going Tubes? (Maybe?)

I ran a C45 with a single MC275 and with Mono 601's. In my opinion the 601's were very close to the sound signature of the MC275, with more depth in the lower frequencies. The 275 placed the vocal/singer a step in front of the "band" and the 601's makes the singer/vocals take a step back. I love the power and ease the 601's drive my speakers. I love how the MC275 looks. I ended up selling the MC275. I'd love to try a C2500/C2600 in my system, but I tried the C2200 before and found I preferred an SS preamp. I say - keep the 601's and try the 2600 or 1100. Let us know how it goes!

I’m sure the C1100 is a step up from the C2600. 
C1100/MC601 combination would be awesome. I’m jealous.

You can always trade up to the C1100 (McIntosh have good resale value). I believe the C2600 is warmer and the C1100 is more resolving or SS leaning. For pure performance the C1100 will be better but the C2600 is already a great choice.

I have to be a heretic here. I've had an ocean of Mc30, 60, 75, 225, 240, 275, and while I loved the look, I was never all that impressed by the sound. On the other hand, I found the rather humble and neglected MA230 to sound better than all of them. Honestly, prices for all those, including the 230 have gone up but generally you can get back about what you spend should you decide to sell. As the risk is low that way, play about!