If affordable to you, you'll want to choose from the McIntosh amps that have the quad-differential circuit. In power amps, that's MC402 and up through the top of the line. Nothing wrong with the MC252, but it's not quad-differential and not quite in the same league. The difference is quite noticeable, IMO.
Once you decide to choose from the quad-diff range, then the improvements get more subtle. Generally 501s are worth the increased cost over a 402, but a 602 is probably the performance-per-dollar peak. The big jump is going to the MC1201 or MC1.2K. You may not need the power, but there's something happening in that Mac circuit at and past the kilowatt range than pushes the speaker crossover out of the way, boosts transparency and introduces a general effortlessness to music that you didn't know you could gain until you hear it.
Phil
Once you decide to choose from the quad-diff range, then the improvements get more subtle. Generally 501s are worth the increased cost over a 402, but a 602 is probably the performance-per-dollar peak. The big jump is going to the MC1201 or MC1.2K. You may not need the power, but there's something happening in that Mac circuit at and past the kilowatt range than pushes the speaker crossover out of the way, boosts transparency and introduces a general effortlessness to music that you didn't know you could gain until you hear it.
Phil