i am an armchair engineer, looking for a little more insight. all comments, suggestions, cheers and jeers are welcome.
Disco Lights for My Pedal -- i haven't seen this feature on a great many pedals, commercial or otherwise. maybe there's a good reason. i have a light plate to add to the bottom of a 1590B enclosure and would love to have it 'flash to the beat', or even simply on off when you play. there seems to be several ways to go about a signal tracking circuit to control an led, including a separate buffer and envelope just to turn an led on/off. not necessarily practical for a smallish box.
i ran across this on amazon,
https://www.amazon.com/DDIY-Controlled-Electronic-Soldering-Four-Color/dp/B07Q2GRS96with some exception about input signal level going into the MIC spot, i think it could work.