Class D amps?

Check out the "Acoustic Imagery ATSAH Monoblocks" or the "Merrill Audio Veritas MonoblockS" amplifiers. These are based on the Hypex Ncore NC12OO modules designed by Bruno Putzeys. The following links will tell you much about amps based on the Ncore modules. Even the basic DIY NC400 module has replaced class A/AB tube and solid state amps in many systems.

http://www.6moons.com/industryfeatures/ncore/1.html
http://www.audiocircle.com/index.php?topic=105310.0
http://www.diyaudio.com/forums/vendors-bazaar/190434-hypex-ncore.html
http://www.gearslutz.com/board/mastering-forum/734095-hypex-ncore.html

Gilmore Raptor 500D monoblocks
Best amps I have ever heard including many tube amps I have owned
Alan

Hypex Ncore (a small-scale true class-A with a proprietary class-D follower stage). I understand these are already very, very good indeed and Ric Schultz of Electronic Visionary Systems (Calif.) has just anounced (a few days ago) his own mods for them on his site.

The only Digital amps I've heard that meet your requirements are the Arion amps, especially the class D hybrid with a tube input stage: http://www.arionaudio.com/
I have heard these amps in several systems and did not notice any of the typical issues with Class D amps.

Here is the Stereophile writeup on teh BEl Canto ref10000M Class D monoblocks that I use.

These were very well received in all aspects and I would agree that the sound overall at least with my gear is hard to fault, though the biggest strengths lie other than at the extreme top end of the audio spectrum, which most guys my age can no longer hear effectively anyway, and not much really occurs musically. I'm not sure there is anything there to indicate any significant rolloff of the top end? How about in comparison to other comparable amps?