I have some really nice Class A amps. Though my fav amp is still the cheaper non-Class A Benchmark AHB2. I just wish it had more power, though in Mono configuration it is high powered for speakers above 2 Ohms. It has that clean Class A sound and is very smooth. I feel it is just the most crystal clean sound I have heard from any amp.
The stock LSA Voyager GAN 350, mentioned a few times above, is good but after the very low-cost mods by EVS it sounded a lot like the AHB2, my highest compliant for an amp. I sold the Voyager since I liked the AHB2 a little more. I kind of wish I kept it as a backup.
As posted above the AHB2 is not Class D.