Not that VTLs were much better than ARCs for repairability! Roger was unique in designing circuits that are reliable, something that has stuck with me. David Manley was another of his faves to ‘discuss’. (Translation...be disturbed by.) I always thought using a hybrid circuit with SS input stage on the RM200 he might offend tube purists, but for him the benefits of having a stable input stage with no drift outweighed the perceived but unwarranted sonic shortcomings. But yes I feel the RM9 is the essential Roger at his best, followed by the revelatory RM10 running its EL84s at 700v and all while keeping dissipation within bounds.
I think you mean self bias, not auto bias? Self bias sets the output stage current by circuit configuration with a reduction in output power, and auto bias is fixed bias with a subcircuit to adjust bias automatically. I think he wanted to eliminate misadjustment of the bias setting as not everyone who wants a nice amplifier is familiar with how to do it. Class A operation means lower and more consistent distortion products.
That brings me to a question, what’s going to happen to his vast collection of equipment, and his schematic designs? I’d possibly be able to make sense of the electrostatic tube driver circuit if I saw it again. It’s probably in a cupboard somewhere.
I think you mean self bias, not auto bias? Self bias sets the output stage current by circuit configuration with a reduction in output power, and auto bias is fixed bias with a subcircuit to adjust bias automatically. I think he wanted to eliminate misadjustment of the bias setting as not everyone who wants a nice amplifier is familiar with how to do it. Class A operation means lower and more consistent distortion products.
That brings me to a question, what’s going to happen to his vast collection of equipment, and his schematic designs? I’d possibly be able to make sense of the electrostatic tube driver circuit if I saw it again. It’s probably in a cupboard somewhere.

