Crimps

Utility module, derivative of Mutable Kinks

Crimps is a 4HP module with Logic, Inversion, Rectification, Min/Max, And/Or, a noise source, and a sample and hold circuit. So I wanted a Sample&Hold module, with some extra features. That sounds like the Mutable Instruments' Kinks.

Kinks is open source, cc-by-sa, so we can build from it if we also open source the derivative. I've totally rewritten the schematic and PCB, but the featureset and interface is identical (sans LEDs). The design files are available on the same license. The only real change is a move to 0805 size parts so human hands can assemble the kit, which necessitated a two-board stack, which in turn made the LEDs difficult to implement, so I've omitted all three blinky-lights from Crimps.

First version is designed and being manufactured, prototype. The V1.0.1 board is in and tests okay: some parts are on wrong so it's tricky to build, but actually works. V1.2.1 is up soon with fixed parts, TBD. If you want the rear-end to look professional, wait until 2022 when the fix is in.

The S&H calls for a better-than-average grade capacitor and opamp, Using a plain opamp where Mutable specified a special one is not great for performance, we need headroom between the negative rail and your input signals, so a rail-to-rail opamp is a good idea, and a TL074 doesn't keep the S&H quiet. If you reduce the noise volume to +/-3V by changing R27 to about 330K, then a TL074 should work.

https://karltron.com/crimps/