Tough amp decision

I would say this is important decision sonically. I would not be in a hurry. MACs have a very distinctive sound. Make sure that is what you want. MacIntosh is frequently paired with B&W… because Mac is very midrange and bass heavy. Great for rock. Lots of folks love them. But there is more nuanced equipment.

You are talking about moving from ARC sound… granted 20 years old to Mac. Make sure you do extensive auditioning.

Also, putting multiple functions in one box normally means compromised sound quality. All the companies are getting better at it. But if sound quality is your top priority, the you want separates. More advances have been made in pre and amp. If space is a problem then this makes sense… depends on your long term strategy… continue improving sound quality of tidy things up.

Going from older equipment to newer is likely to sound better of course.

OP,

If you are not near a dealer, I recommend  weekend trip to a city. Make it a fun mini-vacation. Set up appointments with a couple audio dealers… say you are from out of town. Have them setup and ready when you arrive. If you take your partner plan on dinner and some evening activity. 

The best performing components are separate boxes. I currently have both a stereo Audio Research Reference 160 stereo amplifier and the exact same design / implementation.. Reference 160 mono blocks. So the channels are separated in the mono blocks. There really is no question the mono blocks sound better. Folks may disagree if it is worth the extra cost… but I think few would disagree the mono blocks sound better.

Combining functions (holding other variables the same) reduces sound quality. Interactions of the circuits virtually guarantee this. While design and technology gets better… so does the single box solutions.

So, all things being equal… the less functions the better.

@grislybutter 

At ~$1500… I certainly would not go with mono blocks… a lot of extra chassis cost for inexpensive internal components. Maybe even for separates. My office system has a PrimaLuna integrated amp. I think at that price point… if you choose really carefully integrated is the only thing that will get you near HiFi. 
 

In the audiophile domain, mono blocks win. 

@russ751 

Yes, the Pass INT-60 is a really outstanding sounding integrated. I was really impressed with its rhythm and pace… for an integrated the musicality and nuanced sound and power is very impressive.

OP,

Great to hear your progress.

Just a note. The difference you heard when swapping in the Audio Research preamp with the MAC amp is pretty much the definition of the difference between the house sound Audio Research versus MacIntosh. If you like one versus the other I would stick with the one you like. I prefer Audio Research myself and the pairing of an Audio Research Preamp and amp is ideal. 

Thank you for your kind words.

I think part of having great relationships is to look out for your partner while pursuing your passions. Make sure she is very happy when you go to listen to some systems. 
 

Preamps are the heart of a great system. They take really small signals and carefully amplify them. If you don’t get this right, then the sound coming out will not sound great.

Audio Research tried to transition to solid state. They have had some great sounding solid state components when they were introduced but ultimately went back to tubes. They have a very strong commitment to reproducing music… not designing to fads or flashy sound. So, I think everything is now tubed. And I have auditioned or owned a lot. It is what I choose. Many folks are looking for a different sound. There are lots of companies catering to those sounds.

I personally have become more and more committed to ARC equipment. It embodies what I want in sound quality. Other people want different things. I recommend listening to an all ARC system, and an all MAC, and all Pass. Chose the one you are drawn to. Then over time bring that together. I looked at the JC5… looks like a very fast and powerful amp. My guess is less fleshed out and musical than an ARC. See, what listening says to you… drawn in? Or does it jump out and shout at you. Which do you prefer.

Audio