Chuck D. Bones
Circuit Wizard
I just peeked at the Gloryhole (ok, you can stop snickering now). It already has a booster at the output. One could replace R17 with a C10K pot. If necessary, a small series resistor (470Ω maybe) could be used to limit the max gain.
BTW, some people fiddle C8 & C10 to adjust the brightness. R14 doesn't do anything.
BTW, some people fiddle C8 & C10 to adjust the brightness. R14 doesn't do anything.