McIntosh with Klipsch Palladium P17B

I'm a McIntosh dealer and have heard a lot of their gear over the ten years or so I have been. 

I don't think there's a right answer in terms of tubes vs. SS. And in my experience, as you move through the McIntosh line, their gear can sound pretty different. 

The MC152 is a good amp. I think the MC312 is better and big picture, worth the extra money. I personally own the MC462. It's almost twice the price of the MC152. However, you didn't mention a specific budget that you're looking to stay within and for my money, the 462 is a sweet spot in the line. It's the first and only stereo Quad-Balanced amp. It's dead-quiet and drives just about anything with effortlessness and a sense of ease. 

I also have a fair amount of experience with the MC275 which is a gem of an amplifier in its own right. Voicing isn't so different from the SS transformer-coupled Mac amps, but it does offer an added dose of "classic-tube" sound. You may also be inclined to further tailor the sound to your liking by rolling tubes and the 275 opens that door. I find the Mac-branded JJ tubes to be a little devoid of verve or personality. Not bad, just not exceptional. I've found other combinations that fit my tastes better. I've driven speakers from Kef (R5) through Magico (S1) with a single 275 and have never once heard a trace added energy up top. 

Where things change a bit is with the direct-coupled amps such as the MC830s and the MA252 and 352 integrated amps which I find to sound a little "dryer" or less colorful. I personally find them to pair better with a speaker that's voicing leans toward the warmer side. 

I can't speak to the vintage gear you have and if you want to keep it, that certainly factors in. At the end of the day, if you have a McIntosh dealer in driving distance, I think I'd consider packing the speakers up and taking them in for a listen on either a 312 or 462 (most dealers should have one or the other on hand) and also a 275. You may also want to experiment with different transformer taps. While it may seem counterintuitive, matching the speaker's nominal impedance to the amp's corresponding tap hasn't always worked best in my experience. 

I'd advise you to see if you can borrow amps, but transformer-coupled SS mac amps are back-breaking-heavy, and those glass faceplates are fragile and expensive... Your speakers are easier to move. 

Also, I think it's worth noting that in the real world, a mild rise in frequency response from 11-15K may not be an entirely terrible thing. I'm in my mid 40s and I don't hear as well as I once did, and I find myself wanting for a little air on top with more systems these days. 

@djmika 

Thanks for posting, do you have any opinion on the Mac MB-50 streamer? I use Play-Fi around the house and was thinking about that unit. Thanks

Kota - 

Honestly, I don't have much experience with Play-Fi. As an integrator by trade, we tend to take a little different approach for whole-house music systems. As for Mac, I've never NOT liked anything digital they've done. Their DACs have always been quiet and smooth sounding. I don't necessarily agree with their stance on MQA but that's another story. I suspect this unit is no different. That said, it is out of production and limited to dealer's stock on hand if you want a new unit. I'm not yet aware of a direct replacement. 

I just did a cursory search for Play-Fi "transport" devices you could use with a McIntosh DAC. Finding one new that'll work in a Hi-Fi system seems a little difficult these days so if Play-Fi is important to you, I think I'd call around and try to find an MB20 soon!

Micah

@djmika 

Thanks, I already have a bluesound node and a pardigm link (which I use as a playfi transport) and a Sony TAZH1ES dac. The MB50 can be found preowned for around $1500 and I could use it as either a transport, a dac, or a pre. I was thinking about just getting one at a good deal to compare.

@kota 1

I say go for it. If you don't like it, you can always resell for minimal or no loss. That is an advantage of McIntosh, though I suppose a little less so compared to amplification.