Expanding the Class D Conversation: How Would You Characterize Their Differences?

Useless, in that the question(s) posed by the OP involve too many variables for the collective response to tell anyone anything.

I'd gently disagree that the thread is useless. You're right that implementation matters enormously—that's actually one of the valuable insights that emerged. But the responses did yield something concrete: specific sonic signatures tied to different Class D topologies and designs.

Consider what emerged despite the variables:

Eigentakt implementations (NAD M23, Purifi 1ET9040BA): Described as balanced and articulate with holographic soundstage, but the OP noted the NAD can sound "shouty" on certain tracks—consistent with the analytical character we discussed earlier.

Bel Canto (ICE-based): Neutral yet full and dimensional, avoiding midrange magic loss—older architecture, but still competitive.

AGD (GaN): Exciting transient speed, wonderful frequency balance, image specificity, draws listeners into music rather than fixating on the system—a distinct sonic signature from Eigentakt.

Mola Mola Kaluga (Hypex NC1200-based): Initially impressive dynamics and bass, but became fatiguing and boring compared to Class A/B—suggesting that implementation can miss "musicality" despite raw performance.

Merrill Audio Veritas (Class D): Remarkable clarity in midrange/treble, more powerful bass than tube reference—different character again.

Yes, all these characterization depend on variables, but given that I appreciate what can be, the thread is nevertheless a useful propaedeutic for what I might actually try next. These aren't abstract generalizations—they're concrete guideposts for narrowing my own trials and understanding what to listen for.

You can duck out, of course, if you find it all useless.

@bluorion Thanks for your *useful* comments. 

We each have our own opinion as to "musical". The Crown amp was part of a 4000 watt home theater system involving JBL stage monitors and 18" sub. For HT use, the system made most visits to the theater superfluous, as the better sound was at home. It was never intended for use as a 2-channel stereo system amp, nor did I claim it was. Keep your snark to yourself

@fatdaddy2 You were the one who called the thread "useless." Your snark is evident to everyone here. 

As for the term "musical," yes everyone has something in mind by that term. But that is a truism. If "musical" were purely subjective with no shared meaning, it wouldn't survive as a term in audio discourse. Words persist because they carry *shared meaning*. When someone says an amp sounds "musical" versus "clinical," listeners recognize a real distinction—not an arbitrary one.

Yes, "musical" needs unpacking. But unpacking a term doesn't prove it's meaningless; it proves it has structure. The thread's value lies in exactly that unpacking: people describing what they hear when they use the term. That's empirical observation, not relativism.

After reading @bluethinker's response, and comparing my Atma-Sphere Class D monoblocs, I think the AGD and my Class D's are very similar.  I'm constantly impressed with how I just want to keep listening, how they never seem harsh, have great bass, dynamics, etc.  I'm driving them with a digital frontend and Backert tube preamp, and speakers are J.M. Reynaud Cantibile Jubilees.  The gain on the Class D's is not too high, which might be a concern if I listened at high SPL's.  But that is not the case, and they get plenty loud for me.  I've had older (cheaper) class D amps, and this is a whole other level of sound.  Hope this helps.

I have been listening to my Pass 250, which is class A at my listening level. It’s smooth, rich, and slightly laid back. I always wanted to own a pair of mono blocks and decided now was the time. After much research, I decided on Nuprime EVO TWO SE. These are classified as class AD. Marketing say they can compete with the finest class A. These amps are VERY dynamic and fast! Bass is hit in the chest hard and very articulate. The air is crazy good and has immense width and  depth. lm using a OCTIVE 300SE hybrid pre, and I’m not sure how much it’s contributing to the sound. I did try a PS audio signature pre with the amps, and that was not a good match. I can say these 300watt mono’s bring me closer to the music.