Midipoly, a new MIDI retrofit for Korg Monopoly

One of my personal favourite is Korg Monopoly. Good filter, outstanding oscillator possibilites.
With the release of Midipoly retrofit kit, this synth become a serious sonic weapon and not just a vintage classic.
Addition to MIDI control over the keyboard, cutoff, pitch bend and portamento, the 4 oscillators can be triggered individually with MIDI velocity. The fun begins with the installation which is very easy.

Installation Manual

During the development I spent many hours with just sequencing and tweaking tunes on Monopoly like this


Kicron preliminary info

This upcoming project is called Kicron. Only one voice but that voice kick your body up in your mind...
Kicron is a state-of-the-art analog kick drum generator based on 909 and 808 circuits and concepts.
More than 20 programmable parameters and total MIDI control in a compact form.
Scheduled release in October.


Double kit release on 28/3

Minerva, the ultimate Juno 60 MIDI retrofit is released on 28th of March along with the improved version of Io, the Jupiter 4 retrofit.

Minerva highlights
- Internal non-destructive retrofit, no-drilling installation
- Replaces the patch programmer processor without removing the original CPU
- Full MIDI on keyboard, all programmable sliders and switches back and forth
- MIDI control for pitch bend and arpeggio rate
- Flexible extra LFO, routable to several parameters
- Velocity assignable to VCA or VCF
- Dedicated mono ADSR for the VCF
- Memory upgrade to 80 patches
- Patch dump and controller snapshot for easy sound management
- Price is 129 EUR + 10 EUR shipping fee

Minervadeep by covariance

Io highlights
- Easy to install, modular internal retrofit
- Seperate boards for patch programmer and keyboard assigner extension
- Full MIDI on keyboard, all programmable sliders and switches back and forth
- MIDI control for pitch bend, VCF, VCA, Portamento and arpeggio rate
- Two extra LFOs on pitch bend and VCF
- Memory upgrade to 64 patches
- Price is 129 EUR for the keyboard assigner board and 99 EUR for the patch programmer board

The new version adds master keyboard functionality to Jupiter like it sends note data not just receives.
Old version kits are still available for 99 EUR if you do not need the note sending.


New kits on the block

It's called Minerva and is a very sophisticated add-on for the Roland Juno 60. Planned feature list:

  • MIDI control for all the sliders, switches and the keyboard back and force
  • Memory upgrade to 80 programs
  • Pitch bend and Arpeggio Clock under MIDI control
  • Assignable extra LFO and an extra mono ADSR for the filter
  • Mono mode, Unision mode
  • MIDI Program Change, SysEx dump for the programs
  • Internal retrofit, no drilling installation,

Available from March for 129 EUR.


Noise level mod and more updates

Now noise level can be adjusted as a simple patch parameter which also stored and restored.  Just like on a Juno! Also added a new memory dump function that lets import and export of the whole patch memory. For more convenience the MIDI Thru can be switched off to ease recording multiple takes.  Manual is updated according to these changes.



New chips at my hand. The new Io series will be equipped with fresh Atmel ATTiny4313 micro-controllers.