I have nothing of value to add here yet, but I've been wanting to build a Sta-Levelish for awhile and love that this uses such a basic (and cheap) all-octal tube compliment. I'll be tinkering with this circuit when I get some free time (probably sans the M/S functions). But please keep us posted about your progress! I'm recentish to the forum and gather that Ian's PS PCB's are long sold and not in the group of files he generously open sourced. Does anyone know if those are available anywhere or if there's a similar solution floating around? They would be handy for a couple tube projects I'm sketching out. Thanks!