Best upgrade: amp or pre-amp?

I would never in a million years use those terms. Listen for yourself.

@erik_squires BIG +2. I don’t know who fed you those impressions of Luxman amps, but it makes no sense whatsoever, and I think a Luxman integrated is an excellent recommendation. Luxman will likely give you more detail yet still retain much of the tonal richness and musicality of the Mac gear. To me, Mac gear sounds overly warm and almost mushy. I think Luxman could be a revelation to you. I also agree with earlier post that Hegel, while excellent, may be too much of a shift and may not be to your liking. Anyway, hope this helps, and best of luck.

Speakers

  Focal Sopra 1

No simple answer, but;

While I agree integrateds are a compromise, the Technics SU R 1000 COULD be the one to own

I do not own your kit, but my Audio Alchemy DDP-1 + PS 5 is a pretty good preamp/dac. Last 2 years I tried a lot of power amps, and they all sounded different. The one that stood out from the crowd is my LSA Voyager GaN 350 (MSRP $3000 (same tech as in the Technics)

hth

@ papyneau I guess you will need to decide if you are going with an integrated or not. My personal opinion is the preamp is more important than the amp since it’s closest to the source. I also believe in system matching with separates i.e. using the pre and amp from the same company. Just my preference and you may have good luck using different manufactures but it takes a fair amount of experimenting.

There are some good suggestions on the integrateds. Luxman, Krell, Simaudio, and another one to consider would be the Coda csib. I don’t have any direct experience with Coda but they can be configured in class A and A/B and have been reviewed well. I think at this price point an integrated can provide a better value with a single chassis rather than getting another "box". Of course you lose some flexibility but perhaps not sonics. You won’t really know unless you can listen to the contenders in your or a similar system. Just my two cents.

As @goose  typed, I had always thought that conventional wisdom dictated getting it right up front & then working back.