Nostromotron vanity shots


As of now, I’m close enough to feature completion to know nothing will change anymore with the electronic part. Not much changed since my original post about MIDIfying the monotron ; the only addition was to connect the 5v source of the teensy to the VCC pin of the monotron so the whole thing can be solely powered from a single USB power.

So, rather than having to deal with carrying a break-out-box, I wanted to make it a practical sandwiched unit that would be small and compact.

With that in mind, I made a second copy of the control board that would fit the size of the monotron board (once pulled out of the box) and assemble them using the battery connectors I didn’t need anymore.

The result is an extremely compact unit that only misses a nice faceplate. Here’s a couple of shots.

Size wise, next to another great synth



The two boards stacked on top of each other. You can see the teensy on the right side and the dac in the middle





  1. I found out – from the datasheet of the power supply in the Monotron – that it should be possible to feed the circuit from a +5V power supply. Do you have experience with that? All other sources in the Web makes some crazy efforts to lower the voltage down to +3V…

    1. Yeah.. you can power the monotron from the teensy without any issue. Just connect the 5v pin to VCC. The thing is korg is actually doing some voltage tricks to get the 3v from the battery up to 5v. Vcc bypasses all of that and gets the 5V straight in.

        1. Well, if you feed the Teensy with USB – you get the Vbus-voltage on some pins. The Vbus voltage is +5V. The 3.3V that comes from the internal regulator on the Teensy board – an so you cannot draw anything you like from the board.

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