am surprised that nobody mentioned Spectron amplifier. Its very powerful as many know or should know. From their web site:
ABSOLUTE POWER by James L. Darby:
"Recently, a friend of mine bought a new car - a Bentley Continental GT.....engine was silent and silky smooth and provided the sensation of taking off in 747... That is how I would describe listening to the Spectrons; quiet and luxurious with no sense of effort at any volume level... More than most other amps, the Spectrons allow you to feel the music (not the sound) as well as hear it... Like the Bentley, you don't think to yourself, "Wow! This is powerful!", you are not conscious of the power at all. You are conscious of the music in all its pristine glory without much of a perception of electronics at all; the music just is...Like the Bentley, the Spectrons excel at speed.."
"[Musicians] also were articulate and listenable at low levels. I cannot explain why, but it is true. More than once while playing at background levels, I was drawn in to the music to the point I had to sit down and listen..."
It has enormous headroom i.e. reserve power for crescendos which only a few class A amplifiers have and only Mark Levinson No.53 (at $50k) is another class D amp comparable in that regard.
However, you need not only power but...FINESSE and Spectron which has "Best Sound at CES" Award is one of the best amplifiers I know and tried. My speakers, "Sasha "are most power hungry among Wilson speakers and I am extremely pleased with Spectron I have not only in power but in sheer musicality. I would use word "seductive" describing its sound. Of course good preamp will help too (I have Joule-Electra "450ME").
At $3,995 a piece its not a brainer, I would think!
Mike