I recently upgraded to an Allnic tube system, but had also considered SS, including Class D, as they seem to hold a lot of promise to develop into a best-of-breed amplification solution. I enjoyed the following Class D amps:
- Aavik P580 and P280(at a dealer)
- Mola Mola Kaluga (at a dealer; note: the newer generation Ossetra just came out)
- AGD Audion III (at a show)
They all sounded very impressive: incredible dynamics, fast, taut bass, very airy highs, great imaging. No surprise, given the top-tier systems they were a part of. The Aavik set-up, in particular, with Borresen Z5 cryo speakers and all the Ansuz tweaks, was eerily holographic and resolving. I did not audition any of them at home, in my own system, so it's hard to attribute specific contributions to the amps directly.
Perhaps, my key take-away: it seems possible to build a truly state-of-the-art systems around current class D technology. Modern tube and solid state gear qualia seem to be on a convergence path, with newer tube systems offering improved resolution and tighter bass, and newer SS continuously progressing in imaging and tonal riches.
As with all things audio (and music, and life): it all comes down to preferences. I chose Allnic, since its fantastic combination of dynamics, resolution and timbre / tonality really hits my sweet spot. Still, dealing with tubes remains a mixed blessing - the ability to roll them versus the diminished longevity, heat generation, and overall fussiness. At some point, once they offer that intoxicating last morsel of tube timbre, I still hope to build a SOTA Class D-centric system.