Though I’m a bit too young to experience a true spring reverb pedal, I’m well aware they reign king over today’s digital alternatives. This DIY project from the Electronic Peasant has brought in a Slinky to really make things ridiculous. He’s used the stair-crawling toy to emulate a 1976 spring reverb unit.
How does it work? Glad you asked:
There are a number of different ways to send vibrations travelling down a spring, but most spring reverbs use torsional (rotational) motion, which is less sensitive to interference from external vibrations. Here is an experiment that The Peasant did with a Slinky Jr (R) and some old speaker drivers which delivers loooonng delay low frequency DIY reverb for almost no cost.
If you’re looking for that reverb and barely have enough cash for dinner, might wanna give this a try.