ModBox 37 & Casio SK-1

This is a project I've called the ModBox37. It's a modular performance controller and breakout box with a 37 point patchbay and a few other goodies meant to expand the functionality of external devices, including a Highly Liquid UMR2 which adds MIDI I/O, an LTC1799 precision oscillator for replacing internal clocks and resonators, a simple square/triangle LFO, and a patchable control panel that gives access to touch contacts, photoresistors, momentary pushbuttons, toggle switches, pots at various resistance levels, and multis.

The first device I built out to take advantage of it fully is the pictured Casio SK-1. For as much as I've circuit bent over the years I never took a proper stab at that classic! It connects up to the patchbay via DB37 cable, and hooks into the MIDI I/O circuitry via HD15. It's also got a switch to bypass the SK-1s internal anti-aliasing/lowpass filter, a hard cut switch to the pitch circuit (for using the ltc1799 as a clock replacement), and a matching paint job.

Progress photos

Patch & Control Layout

back panel-01.png

The “currently unassigned” bits were initially for a dedicated filter, but I’ve had issues adapting the filter I built to this ecosystem. I may revisit it/build a different one and implement it later, but I may also just build a 555 Atari Punk Console and use the available patch points and two knobs for controlling that & adding CV in to it.

SK-1 & Misc. Reference

July, 2019