Hi Bob!
Ayre is a very interesting amp design. The diamond circuit is one I fell in love with and don't really know why, despite a number of serious criticisms of it's technical performance.
It falls short of perfection but I really love the sound. I also love the sound of it implemented as a headphone amp. The Pono and Codex are among the best headphone amps I've ever heard.
Now, as for the speaker amps.... this is going to sound really weird, because I can't really connect what I hear with a technical measurement.
Ayre amps provide a lush dark backdrop which I've heard in no other amplifier. I don't mean they are dark sounding (i.e. reduced treble) but that the sound seems to emanate from absolute nothingness and explode without boundaries. An effect I've not heard in any other amplifier.
The argument can be made that there are colorations... but if so I can't describe them with the normal verbage.
D'Agostino lacks that, IMHO, but then, that's an Ayre signature quality. D'Agostino is like heavy lightning. Utterly smooth, no noise, no grain, also without a limit into the treble or bass.
I find the D'Agostinos and Luxmans to be a lot more similar than they are different.
All the amps in the A category I've listed make the B class seem restricted, like not enough energy comes out in the bass or the treble, and have an utter smoothness and liquidity the B class lacks.
Best,
E
