Ampeg B100R turn-off pop
 

The Ampeg B100R mystery turn-off pop has been solved. Mine didn't pop when I turned it off, I figured maybe it was a later model and it had been addressed.

Mine also had a burned out indicator lamp. I just fixed the lamp, so now I too get the mystery turn-off pop. While it's nice to be part of the club now, tomorrow I'm taking the bulb out.