Release status: stable

Description PCB design for Jan Ost’s O2 synth (Korg Mini Pops Clone)
Last Version  0.1 (2020-08-16)
Platform  Arduino ProMini
Download  GitHub (PCB), Firmware
Minipops on

PCB for Jan Ost’s O2 Synth

Like the Minipops 7 rhythm box? Yes, the one that Jean Michel Jarre used on the Oxygen album.

Here is the source code to build one yourself.

It runs unmodified on any Arduino.

  • Tempo and 16 pattern select CV input.
  • 8 drum mute inputs.
  • Run/stop input and clock/reset outputs.

You can easily add a CD4067 AMUX chip for driving an analog sequencer in parallel with the rhythm pattern.

The code is licensed as “Free for non commercial use”, so I’m not selling these. If you want a PCB, I might have some spares, and I’ll give them to you for whatever I paid for it.


  • 16 patterns, selectable via potentiometer
  • Tempo selectable via potentiometer
  • 8 mute switches
  • Run/stop switch
  • Audio out via 3.5mm stereo plug
  • Optional sync out via audio plug, compatible to Teenage Engineering Pocket Operators



Part of Circuit Reference Part Number Distributor Amount
 Arduino uP1 Arduino Pro Mini 5V 16Mhz   1
Potentiometers  RV1, RV2 10kΩ lin, P09 style, e.g. P090S-14T20BR10K Digikey 2
Resistors R1, R2 1kΩ   2
LED D1 5mm, yellow   1
Switches SW1 - SW9 Kippschalter mouser 9
    Schiebeschalter mouser 9

Known issues

  • LED D1 does not shine very bright, probably due to a fairly short clock impulse. Might help to decrease the resistor R1 quite a bit, but I haven’t tested that yet.

Further reading