Midi interface for Organs, String Machines and Polyphonic Synthesizers

Description | Machines and manuals | Configurator | Order online


OrganDonor is a universal midi interface for electronic organs, string machines and polyphonic synthesizers. It can be used to midify machines where other approaches fail. OrganDonor uses analogue switches to directly simulate keyboard presses. A large voltage range of up to +-20V allows interfacing even the most vintage machines.
In addition, parameters such as filter cutoff, glide or preset selection switches can often be interfaced as well.
The modular approach lets you add as many analogue switches as needed. This allows even large polyphonic synthesizers or organs with several manuals to be interfaced.


We offer OrganDonor as customized versions for particular synthesizers. We are working on expanding the portfolio and creating more installation manuals. Contact us if your synth is not on the list yet, or if you want OrganDonor installed in your synth by us.

Additionally, the behaviour of OrganDonor is fully customizable via the OrganDonor configurator. This is a browser based tool that allows you to create midi assignments to analogue switches, digital outputs, PWM outputs and CV/Gate output (special OrganDonor version needed for CV-out). User manual here.

organDonor installed in a Roland RS-202

List of machines and Installation manuals

Click on a Link to get to the specific installation manual. If there is no link, we think OrganDonor will work with this machine, but were not able to try it yet.
Your synth is not on the list at all? Contact us!


Korg PE-1000
Korg PE-2000
Korg Lamda ES-50
Korg Delta DL-50 (Handled by Lalaland Kit)
Korg VC-10
Korg PS-3100
Korg PS-3200
Korg PS-3300


Roland RS-09
Roland RS-101
Roland RS-202
Roland RS-505
Roland VP-330
Roland VK-1


Yamaha SK-10
Yamaha SS-30

Yamaha SK-15 (covered by TM62100)
Yamaha SK-20 (covered by TM62100)
Yamaha SK-30 (covered by TM62100)
Yamaha SK-50D (covered by TM62100)


ARP / Eminent Solina String Ensemble
Arp Solina String Synthesizer(manual incoming)
Arp Omni
Arp Quartet
Arp Quadra (not supported due to SPDT key contacts)


Elka Rhapsody 490
ELKA Rhapsody 610
ELKA Solist 505


Moog Opus 3
Moog Polymoog (not supported due to SPDT key contacts)


Crumar Performer
Multiman (not supported due to SPDT key contacts)
Crumar Road Racer (not supported without removing the keyboard due to SPDT key contacts)


Hohner/Logan String Melody
Hohner Stringer /Elka K4 / Elex K4
Hohner Basset (Uses normally closed switches, can only be controlled when removing the original keyboard)
Hohner Basset
Hohner Bass and Bass 2


Vermona Strings
Vermona Piano Strings

Siel Cruise
Siel Orchestra
Siel Orchestra 2


Oberheim 4-/8-Voice FVS-1


Kawai SX-210