Kleingorium is an extension board that modifies incoming waves and generates harmonic frequency multiplications and divisions (all are square waves). It can generate arpeggios and melodies when it behaves well and glitch sounds when it doesn't, which are tuned to exact multiples and divisors of the incoming wave frequency (3/2 for a fifth, 5/4 for a third, 9/8 for a second and so on).

I have been developing it since May this year, and it's open hardware: it uses CD4XXXX series chips, which are digital but they can be (ab)used outside of their normal operation into the analog/glitch realm. These kind of "synthesizers" are called Lunetta after Stanley Lunetta.

To produce the sounds I'm using another Lunetta-style board, but the idea is to have a self-contained unit in the future (maybe 40c3?)