@ 62Caddy, which unit do you find your self listening to, or using the most, and what is it about that unit that separates it from the rest?
That is a good question but difficult to answer because of the variables involved. The main system uses the three largest amplifiers and either an MC 240 or MC 2505 powers the vintage system - plus the speakers are different in the two systems.
However, a few observations I have made:
1. MC 240 and MC 2505 sound surprisingly similar, not to say identical - to my ears at any rate. Sometimes the 2505 seems to have a slight edge in bass extension, more so at higher listening levels. I've A/B'ed them quite a lot with an amplifier switcher and I doubt many souls could positively say which amplifier of the two is running.
2. MC 2125 & 2155 are, for all practical purposes identical sounding amplifiers - except slightly more power of the 2155.
3. Comparing MC 2505 with 2125 - the 2505 seems to have a slightly mellower character. That is not to say highs are lacking in the 2505, they're a tad softer than with the 2125.
4. Despite the considerably less elaborate setup of the vintage system (2 speakers instead of 6) and with tube tuner-preamp (MX110) vs SS preamp, this is a system that could satisfy me forever. Although it doesn't have the outer reaches or earth shaking capacity of the larger system, but for an honest & credible performance, it can't be beat.
5. I have come to the realization that power amplifiers impart far less "signature" on a setup than the preamplifier.
Generally speaking, what I like about McIntosh equipment is its excellent overall tonal balance and musicality. Everything seems to fit just so - as the musicians and engineers intended - if that makes any sense.
Eric