Copy that. Noted. My primary motivation here was that I built an AB a long time ago for a Plexi-Plus and couldn’t get either to work. I separated them out and eventually got the Plexi up and running and it’s great. So now I have an orphaned AB that I’d love to have operational so that I could test it with various circuits before I commit it to the build. I have never managed to get that first one rolling, despite changing Q1 and rebiasing and endless poking. I bought two at once and I’m about to populate the second one just to see if I cooked the switch way back when I was new. Incidentally the S3 may be a better solution for my Plexi project anyhow. I’m familiar with the circuit- it’s the post boost in my profile shot. I’ll look into that as well. Thank you.