frame drum

Frame drum is a eurorack 4 channel analog percussion instrument. It is based on the Gamelan Resonator concept first utilized by Paul Demarinis in his ‘Pygmy Gamelan’ … https://pauldemarinis.org …. I’ve been kind of obsessed with it … but had also forgotten about it :) Trolling about looking at interesting ideas, as I often do, I was reading schematics from non-linear circuits … and they had a module that used the concept. https://www.nonlinearcircuits.com/modules/p/tinkle?rq=tinkle And I was flooded with memories of toying with the idea that were 30+ years old. My circuit takes some ideas from non-linear but takes off from the original and nlcs.

And here some fuzz orientalist foo from therack with gratuitous filter foo. And the frame drum, Of course! The vca in use for therack is portcullis.

Ok, long story short. It’s just an LM3900 operatkional amplifier (not your ordinary op-amp!) and an arangement of capacitors. usually, three of the same value. Oh, you can play endlessly with the values.

The unique thing about the circuit is the reverberation of the capacitors. It’s very warm. On the deep end, it’s all ‘frame drum’. Hence the name.

This is still a work in progress :)

Open Sources includes fritzing files, and the gerber files when the final production run comes in.