Balanced summer at the bottom. I rarely sum externally these days, but I can. Octal tube pre, fast sounding FET and M1 inspired pre...still work to be done in here.
Galvanized steel sheet, the thinnest I could find. I lost my phone in Dominca Republic with the build pics. Transformer balanced Fet pre, no corners cut. And I kept the amp flat and created and saved a preset for driving it. Dynamically compressing the plate resonance to keep it sounding nice.
You diy the plate i imagine. Which kind of material have you choosed for the foil? Stainless steel?
This is impressive amount of diy gear you did Analag.