Who tried Class D only to return to S/S or Tube

It's interesting to follow the development and different incarnations of Class-D amps, and lately Devialet and in particular the NCore-based solutions have caught my attention the most - sadly not via auditions in my own setup.

To me though the choice of amp comes down to the choice of speakers first and foremost, and being that I favor speakers of high(er) sensitivity (not necessarily as a means in itself, but as a function of their design/principle and the sound this produces), I'm not sure generally high-power Class-D is the best option. Here the first watts or less are what counts, and Class-D topology seems to be "more happy" going beyond these lower thresholds.

Interesting as well is reading the notions of the supposed "neutrality" of Class-D amps, which appear to be influenced to some degree by an array of their measured performances as an "objective" criteria. The criteria essentially can only be what is actually heard, and if what is heard distances itself the most from any mechanical, dynamically restrained and tonally inauthentic imprinting, the more natural and "neutral" it is in approximating a live, acoustic sound, to my ears.

The development in my setup, as per before mentioned desirable sonic traits, has lately gone from Class-D to SS Class-A, and who knows whether a 3-4 watt SET would take the reign in the near future to come. Certainly not a "modern" development, indeed it's rather old fashioned, but why should one care? On the other hand, should a Class-D based iteration cross the way and level the Class-A/SET alternatives with high sensitivity speakers of choice, well then, it's a hassle-free and greener solution for sure.

11-28-15: Kijanki
My Rowland 102 sounded the best after about 400 hours. Class D amps are very revealing and often don't work well with some "bright" components. [...]

The exposure goes both ways; what's at the end of the signal chain (i.e.: speakers) can also be ruthlessly revealing as well as, conversely, reveal their limitations. When people describe SET's as possessing "lush, warm [i.e.: meant as warmer than strictly "neutral"] midrange" and generally "loose bass," it could be descriptive of speakers lacking mids resolution/speed and of (bass-)ported designs with poor damping and overhang. Connect well-implemented horn speakers instead (themselves far more revealing than most direct radiating designs) with non-ported bass of higher damping and the "math" can suddenly reverse into match-bliss: here the mids are no longer warmish warm, but attain a "bloom" and naturalness that's ultimately freeing of any containment resembling "hifi" in the usual sense, and a bass enriched with an organic imprinting more about texture, immersion and cohesion (traits of true horn bass as well) than oomph, attention-seeking and depth.

If one were to insert a Class-D amp here instead (many iterations though they are), and the sound suddenly became slightly bleached, bass-thin and lacking fullness (that's a guess), my take would be to assess the amp lacking harmonic richness and being over-damped in this particular setup rather than aiming the search light towards other components - not least the speakers. Though speakers (and their acoustic environment) are by far the most coloring and limiting factors, their potential to put into perspective on what to use earlier in the chain is significant.