Buy the RK-002

Popular uses

  • Change KORG volca Sample control from one MIDI channel and adding chromatic play control.
  • Adds arpeggiator functionality to existing MIDI data.
  • Adds KORG volca FM velocity sensitivity.
  • Add parameter control to Roland Boutique Synths.
  • …and much more…

Here's a video with Sonicstate’s Nick and Gaz having a ball with the RK-002 (mind you the RK-002 now is shipped with a new 3D-printed orange plug end as opposed to the version in the video. Also we have increased the length to 1.5m).

The RK-002 ‘Smart MIDI cable’ has already found it’s way in various setups, not just for the volca Sample. It looks like a +/-1.5m ordinary  male-male MIDI-cable but has a microprocessor on board which ‘bends’ midi data on the fly.

We initially developed the RK-002 to solve the KORG volca Sample’s MIDI behaviour but in the meantime we have brought various other firmware flavours:

  • Arpeggiator firmware
    Adds arpeggiator capabilities to your MIDI
  • KORG volca FM firmware (or Roland Boutiques)
    Actually not only to add velocity data to the volca FM – it’s a more versatile firmware version which is able to add extra controller mapping to key, aftertouch, pitch and modulation. This can come in handy on various MIDI devices.
  • KORG Kaossilator firmware
    This firmware allows you to play the KORG Kaossilator from a regular MIDI keyboard.


The RK002 firmware is updatable via MIDI, you can implement the RK-002’s sysex messages in e.g. a MIDI controller or visit the settings page. In this page it’s also possible to change the parameter mapping.


To keep things portable and solderless we decided to make the RK-002 MIDI-Powered. This means the embedded controller is powered by the MIDI bus and you don’t need an extra power supply. Beware though: Although power consumption is very, very low: Not every MIDI interface or device supports MIDI power! In order to make the RK-002 work in these cases there are multiple options, but if you want to work with what you have at hand; Sometimes looping the RK-002 through another synthesizer’s MIDI-In -> MIDI-Thru port can solve the problem. Our RK-004 MIDI merger/splitter also does the trick.


You can drive the RK-002 via our RK-004 when you set the MIDI port to ‘out mode’. Added bonus on the RK-004 is that you can update the firmware via an audio signal, e.g. people who use the RK-002 with the BeatStep Pro (which filters out our firmware SysEx messages) can now update their RK-002 via a plain and simple MP3 file.

This entry was posted in RK002.