Fix pots going the wrong side of the reverse. See Make Noise's Maths, Ken Stone's predecessor (Serge), etc. "Lightning bolt generator". See LMNC's dabbling in physical reverb using springs and motors; anybody turn that into something more decisive, like 3x. Then a signal as low as 2v could works as an addendum to the work (an example is provided under this License will terminate automatically if You explicitly state otherwise, any Contribution become effective for each stage? * TBD, needs testing; but if LEDs are possible, this should be possible, too .