To a large degree, the sound of a product comes from general implementation and engineering, not the class of operation, the chip used, and so on.
It’s a design choice. Ralph Karsten designs his Atma-sphere amps to run in Class A.
So does Tim de Paravicini. I believe it’s a design to lower distortion and colouration.
Nelson Pass designs some of the Pass amps and First Watt to operate exclusively in Class A.
I own an EAR Push-Pull Class A amp and the sonics are a clean reproduction of the recorded material. The downside is the heat generated from the amp. But this was not a consideration when choosing which amp to buy, I chose the component based on performance and
sound quality.