Amp upgrade from Ayre V-5xe

I bet you’ll be happy!

one of the reasons Ayre made quick  update ( twenty version) of his diamond output amps, is because they had trouble with overheating

I don’t think that’s quite right, certainly not the full story. Yes, the originals ran hot but what evidence do you have that it was to the point of overheating?

Meanwhile, you can read about the changes and the motivation here:  Ohttps://www.soundstageultra.com/index.php/equipment-menu/658-ayre-acoustics-ax-5-twenty-integrated-a...

reports of the non 20 version shutting down on heat protection.

Well, that’s compelling evidence of a problem that needed to be fixed but the Twenty version is so much more than addressing excess heat. And it’s obvious on face value that they did not have the original and the Twenty versions to compare when they introduced the series. It appears that the Twenty came at a time of rapid advances in their circuit design. Being upgradeable, why wait if a substantial performance gain can be had? IIRC, the R series was soon thereafter updated to Twenty series because the “affordable” 5s had nearly closed the gap sonically.  

Ayre has been candid about the origins of the diamond circuit. Not sure your point about “perfected” but my snarkmeter is ringing.