Some nice elements to that design Dwight and both Intact and Monolith do good stuff. Tidy, compact build. Good to see the TentLabs mini eChokes getting a run - almost designed them into my next build and I’d like to use them in future. Is Jac warranting his tubes for use with the more recent versions of the Coleman Regs? What is the configuration of the 6N7 twin triodes - paralleled plate, single plate used (able to alternate plates), other?
A 2A3 running at “classic” operating points (250V/60ma/2K5 load) will make 5W, albeit at roughly 7% H2 distortion, before the grid swings to 0V and the sound can get a bit nasty; at 3.5W the 2A3 is generating an estimated 5% H2. I don't see the RS-3 transformer on the Monolith site, but I assume something like a 3K to 3K3 primary, which at the operating points shown for this amp and not drawing the lines, should produce around 5W at around 5% H2 distortion with a bit of available headroom.
I run EML 2A3-S as my daily drive; the JJ 2A3-40 sits in cupboard in case of emergencies.