Video showing midi to coil

Here is a video showing a custom midi interface developed by Tubbutec for analogue drum machines such as Korg Minipops, AceTone RythmAce, Maestro Rhythm King MRK-2, Roland TR77,…

It has the following features:

  • 16 pulse out channels + Guiro output and pitch control
  • Outputs selectable between +5V..+12V and -12V
  • Fully velocity sensitive
  • Adjustable pulse length between 0.3 and 1.3 ms
  • Midi learn


Midified CR78 and TR606 sound demos

Here are two sound demos of a TR606 and a CR78 I midified.

Note the full velocity sensitivity capability of the 606 and the pseudo-velocity sensitivity of the CR78.



Some more infos about the CR78 mod:

Depending on the midi velocity sent to the device, the master volume is adjusted. That is of course not the same as full velocity sensitivity, but gives you a surprisingly great amount of flexibility. Think of the 808 for example which has one accent track – this is similar, but you can adjust the accent on the fly.

4x Midi CV Interface rev.2

While waiting for my Polysix mod PCB, I am working on rev. 2 of my midi to cv interface. Rev 1 was working well, but I realized I wanted some more features.


The new one will have:

  • 4 x CV out, 12 bit precision each
  • 4x Gate
  • Glide / portamento control for CV outs
  • For each CV you can switch glide mode between (on/auto/off)
  • For CV 3/4 you can choose individually whether they output midi notes or midi velocity from CV 1/2
  • Each CV can be controlled by midi notes and midi controller
  • FM in
  • Midi learn
  • Leds for gate and CV out
  • Doesn’t use smd parts an can be built by everyone

This basically enables you to have 4x polyphony with a modular synthesizer !…..and much more 🙂


Developing a midi interface for Elektor Formant

Elektor Formant Midi Interface (6)

I am currently working on a midi interface for the Elektor Formant. Of course it is possible to use any midi to CV interface since it is a modular synthesizer, but I wanted to add some features only possible with a custom interface. With this interface it is even possible to have 3 voice polyphony !!!

Features so far:

  • 4 individual CV outs. 2×12 bit high precision, 2×8 bit
  • Glide and master pitch controls
  • FM input
  • CVs are controllable by midi notes or controller messages
  • Leds for CVs and Gate
  • Switch between standard kexboard and midi interface

Planned features:

  • Analog gates
  • auto glide (switch glide on and off)
  • nice front panel

This is the prototype PCB:

elektor formant midi interface

I am going to sell PCBs (much nicer ones than the one on the left of course) as kits if there is enough interest in the interface…so drop me a message