MrBook has shared documentation on his awesome hack to add MIDI to the Gakken SX-150 synthesizer.
Here’s what you’ll need to turn the Gakken SX-150 into a MIDI synthesizer:
- Gakken SX-150 Analog Synthesizer Kit
- Arduino (This one is the classic, but my favorite ones, are the ones from Modern Device)
- MCP4921 12-bit DAC
- 4N28 Optoisolator
- 1/4” Audio Jack
- DIN 5 Pin Chassis Socket (Female MIDI plug)
- Diode (N4148)
- Resistors(220 ohm, 100k ohm and 3.3k ohm)
- Wire, breadboard (or wherever you wanna do the circuit), soldering stuff and patience.
Details at MrBooks’ site. See this previous post for a demo of the Gakken SX-150 being sequenced by Ableton Live.