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

@niodari 

I’ve only experienced the PASS XA-25 and the SIT 3. The Pass has, overall in my system, a punchier feel to notes and percussion, firmer tonality – richer, deeper broader hue, clearer articulation and more 3D dynamics, a bit wider soundstage – overall, just more present and real.

That said, the SIT-3 has many of these qualities in superior ways to other amplifiers – plus, a supremely delicate and natural presence. Grip is articulation + dynamics + speed -- taut bass, effortless in fast transitions. Yes, presence is the feeling that the musicians are in the room but it’s also a certain tonality. Not edged with clarity – as every class D amp I've heard either does or nearly does – but more like present from the middle outwards. A warmish hue.

Good to hear about your ​Chinese Pass F7 clone​. I don’t find my Pass – which is really unique in the Pass line (read about it) does not have an artificially coloured sound. I have heard good things about the F7. You describe it like I would describe my Pass.

All of these amps are present and tonally gentle, rich, and real in ways the AGD, NAD, Hypex I have tried are not. Without tonality and presence, they are not nearly in the same league, in my opinion – with my speakers, in room, for my tastes, of course.

I hold out hope that Atmasphere may be the amplifier that reaches into the category of sound that I’m interested in. My hope is that his decades of experience as a tube amp designer gives him the experience and ear for that, at least.

I'm late to this very good discussion. At this year's Axpona madhouse the only thing that made me rethink redoing my just finished system was the Devialet class A/D equipment. Even in those poor (acoustic wise) rooms they were the standout. Lordy!  

They are not cheap but given their integrated chops they have considerable value. They can also be used as mono AMPs yielding 600 Watts per side if 300W per side isn't enough. The remote volume controll just plain sexy. 

Oh là là. Its sont fantastiques. J'adore ça, Daddyoh!

Here is my two cents: I have not experienced listening to many Class D amps, but I have not yet heard one that would sway me into buying it over a comparably priced A/AB amp. That said, there are advantages in weight and size of most Class Ds. But they seem to lack the weight of the bass and they sound rolled off in the highs to me. In all fairness it could have been the amps I have heard (none above the$6K price point). But I am still not convinced.

And as a side note, I have a close friend that has an incredible system with Sound Lab A1 speakers with a home-made tube pre-amp and Jeff Rowland amps & DAC. He has personally known Mr. Rowland since at least the 1980s when Jeff was just doing electronic repairs and started developing his own amplifiers and formed Rowland Research. I remember my friend telling me about the excitement Rowland had about the "new" ICE module that was the beginning of the Class D era. That was over twenty years ago. After trying to make the Class D amps, Rowland eventually gave up and abandoned the technology as he could never get fully satisfied with the end result; he could not get the sound to be up to his high standards. Today, if you look at the brands offering Class D, it seems to be many of the mass marketing manufacturers, because they can be made affordably. Now of course there may be exceptions to that, with some specialized boutique firms still trying to make it work. I think that speaks for itself: the sound of Class D is still evolving, but when a well respected high end amplifier engineer leaves it aside, I will too.

@cooperdude6 – YES to your post. Yes, yes, yes!

So...Listening update: I had a chance to hear the Boulder 866 amp in my system, with all the same variables the same (as my other amp trials).

The Boulder has all the benefits of the Class D amps I heard, but none of the downsides. Lots of great, tight bass, crisp percussion, and accurate and natural midrange that is not warm like my Pass but not Benchmark sterile. Music sounded natural, soundstage was fantastic.

This data point tells me – for my ears, in my system – that good Class A/B amp can do the things I thought I had to go to Class D for. I no longer think that. There is nothing "inevitable" about Class D to me, and the Class A/B used market has lots of options.

I've had personal experience with a handful of Class D amps and heard many more at some shows. I've always experienced the most musical result when they have been combined with tube preamps.  And of course, the cables and speakers make a difference, too.