It was a sad day when the class-A retired.
This was a REAL class-A. No global feedback, single-stage FET-cascode voltage stage running on high voltage supply - regulated, of course, current amplifier with local feedback only, drives any load - ANY - even a short, low power, automatic self-destruction if the fan stops.
Circuit designed for distortion profile with falling higher order harmonics, for that magic class-A sound. With the one-stage amplification and no global feedback and class-A, it is the ultimate audiophile design.
But this was in the days before considering how hearing actually works, so there is one major fault with this concept - since I was reluctant to build an amplifier with high distortion, I designed it with very low distortion, which, as we know now, means the distortion is never audible, so the distortion profile does not matter for sound, just for the story and on-paper.
The amplifiers I use today have 20x power, occupies less than 1/4 space, runs at cold 30 degrees - the class-A was 65 degrees, and even better sound because they have lower noise.