About Me

currently on the way to become a mechanical engineer. here are the things that I do on the way.

Build and Hack Stuff

Monotron Duo

I have been slowly entering back into the world of music, although this time with electronic music and synthesis. It will really give me a chance to converge my artist side with my engineer side. I see myself in the future synthesizing sounds and creating songs that are heavily influenced by the instruments I create or bend.

Well that’s great and all, but I didn’t even have something simple that I could easily lay down sounds with besides a computer keyboard/mouse. I really wanted a set of keys but I’ve no money at the time – then I found the Korg Monotron.

The Korg Monotron is a contemporary analog ribbon pocket-sized synthesizer that can be purchased for around $40-$60 depending on your favorite music vendor. It fits in the palm of your hand, has a few knobs to control tone/effects,  along with a built in speaker and battery power. It doesn’t have real keys – instead, an analog ribbon you can play with your finger or a stylus.

There are three Monotrons out right now – the Duo, Delay, and standard – and I was close to going with the standard. By instinct I wanted to start with simple and get complex later. At the last minute I decided that this type of simple was to simple and I wanted to take it a step further – I picked the Duo.

Korg Monotron Duo

The Monotron Duo has two separate oscillators, a cross-modulator, and a filter. Having the double oscillators greatly expands the range of fun that can be had here.

What’s even better, is that Korg released the schematics for all three devices, and has clearly labeled some useful points on the back of the PCB – as if they are encouraging modding of the device.

It’s pretty versatile already, with the ability to just use it as an effects processor for other instruments (run your guitar through it), but why mod it?

Because other awesome things can happen with it. Just add external CV/Gate control and run a Baby10 step sequencer, and fun has multiplied by twenty. This kicks my previous idea‘s ass all day.

Here’s a photo of the back side of the PCB (not my photo, it came from the user ‘reve’ on electro-music.com

the back of the monotron duo pcb

I have had loads of fun with it so far. Some people that post reviews about it (particularly on amazon.com where moms/dads buy this for their kid as a birthday gift), find it to be a rather expensive, flimsy, and capability-limited toy for today’s age. Well it’s not an iPad, it’s an analog synth that is designed to be simple and cheap. I keep it in my bag and play it while waiting around doing errands, parked waiting to pickup Katelynn from class, in the bathroom (yeah), or between calls while at work.

I haven’t found the courage to start bending my new $50 toy yet, but I’ve at least opened it up. For it’s size, it seems to have plenty of room for any wiring that will need to be routed from the designated pads to the case – I’m eyeballing some old ribbon cables I’ve collected over the years. Once I make more progress on my sequencer project, I’ll add this to the mix and hopefully make some dirty magic.

Here are some other useful links to modding the monotron family:

DIN Sync has details on the standard monotron and the pads on the back of the PCB

Adafruit article on the schematic release

This guy DJ Jondent has a video showing wires being soldered to the pads for the Monotron Duo

Here’s a guy who wrote up a design/schematic using a Baby10 sequencer with the standard Monotron (in Japaneese, google translate works good – or just check the schematic)

User reve on electro-music.com started a thread that led to some good information and findings on modding the Monotron Duo

There seems to be much more information about modding the standard than there is for the Duo or Delay. I hope this collection of links helps someone out (it helped me) and I’ll add more good stuff as I come across it.

Post in the comments if you have any good findings for bending/modding the Duo, Delay or Standard.

2 Responses to “Monotron Duo”

  1. sid says:

    Thx bunch!…highly appreciate it

  2. Tom says:

    I have the Monotron Duo. I see the solder pad marked “cutoff”. Which other solder pad do I need to solder onto to control the filter cutoff frequency with a control voltage from my Korg SQ1?

Leave a Reply