most clear, crisp sound power amps, monoblocks ?

Live sound is only relevant as a reference if unamplified...otherwise get a PA system and sit 100 feet from it. My current hifi system sounds great to me, but that's likely due to ear damage and personal taste developed from spending over 4 decades as a musician and live sound mixer, which I still do and from which I shall never recover.

The "live sound" reference idea is lame, meaningless, and should be abandoned. Maybe replace it with "well recorded" or "sounds good to me."