Questions re:  GaNfet technology vs other designs.

Don't let yourself fall into the trap of "musical" / engaging. Mainly that comes from a non-flat frequency response, and that could be correcting something else in your system or just be something you like. There are other easier and more reliable ways to do that.

@hgeifman 

I own class D amps from Nuprime and AGD. Both are musical and engaging. I would agree with @theaudioamp that the problem might not be the amps alone but could be a pairing combination. Synergy between gears can be tricky. Don’t get discouraged though. The road to Audio Nirvana is not straight. It has a lot of curves, some ups and downs and round a-bouts that sometimes makes you go in circle. The journey is fun though. Enjoy the scenery while you can. 

Try to listen to Atmasphere's class D monoblocks or any of the AGD models.  Currently (no pun intended) those are the best bets for what you're looking for.  The Orchard Ultra Stereo looks promising, but I can't speak to it directly.

Don't let yourself fall into the trap of "musical" / engaging. Mainly that comes from a non-flat frequency response

@theaudioamp This statement is incorrect. The ear converts distortion into tonality; actually the reason some amps sound musical and others do not is the distortion signature of the amp (often referred to by audiophiles as the 'sonic signature') rather than a frequency response error.

This is why you can measure two amps on the bench that are equally flat in frequency response but one will sound bright and the other doesn't. Higher ordered harmonics (the 5th and above) are perceived by the ear as harshness and brightness if they are not masked by lower ordered harmonics. This is a problem with most solid state amps made and why tubes are still around. But if the solid state amp has the right distortion spectra (lower orders dominating) it can sound as smooth and musical as a tube amp, yet will have nice flat frequency response.

@atmasphere 

Thanks for correcting the misinformation post (Although I'm sure it was well intended).

Charles