Building new system starting with power amp. What would you choose ?

Gryphon is what immediately came to mind as soon as I read your notional budget. The Diablo is hard to beat for overall sound quality in a neat package, especially if you have no desire to fuss with tubes. Solid state really doesn’t get any better at that price point.

I personally might do an Ayre or a D'Agostino.  however, I'd definitely have speakers in mind.

What I normally suggest people listen to are:

• Ayre
• Luxman
• Pass
• D'Agostino

This gives a nice spread of amps and sound qualities.  Luxman and D'Agostino more similar than not, Pass and Ayre taking decidedly different approaches.

If I was going to use a high efficiency Klipsch, Tannoy or Altec type of set up Pass would be high on my list, but honestly I tend to stick to small footprint conventional multi-way speakers. Wilson's being among the largest I'd consider.

"...perfect minimalist audiophile set-up..."

Still needs a pre-amp.  

Levinson ML-2 is a great idea. Can it still be serviced ? I read about it but never heard it.
Gryphon Diablo is yes, basically a power amp with passive preamp. However, I would try to find used Gryphon Class A power amp. instead of it first.

Sanders sound Magtech mono blocs. 
 Any warm speaker. (86-90 db 1w/1m)
 CJ  ET5 SE. 
 Rotel 1572 CD player.Audioquest cables.

 8 ga speaker cables.

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