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Roland Juno-6 MIDI Retrofit

Roland Juno 6 MIDI retrofit

Note: as this is a very old article, some links are unfortunately broken but I leave them here in case someone wants to investigate.

Presentation of the retrofit


Mungo Enterprises Juno Midi Retrofit is placed between the Juno’s keyboard and main board, and basically translates MIDI data into keyboard messages. It works as if the MIDI sequences were played on the Juno’s keyboard :)


It also adds the possibility to sync the Juno’s arpeggio to MIDI clock, but I did not installed it, it is optional and I don’t really need that (arpeggios are written in my DAW).


This retrofit does not allow to control filters (or other params) via MIDI like the Kenton one, but it is way cheaper! The Kenton costs £330 if you install it by yourself, while the Mungo is $99AUD (+some components you will buy at your local dealer).



This article is here to give you some help with pictures


If you plan to install the Mungo retrofit to your Juno (it also works with other synths), these pics may help you, as an add-on to the provided instructions pdf.


This blog by Andrew Martens may also be very helpful.

1) Getting started
2) Board B - Top view

Before soldering power and keyboard cables

3) Board B - Bottom view

Before soldering power and keyboard cables

4) Board B - Top view

With all cables, when retrofit is installed

5) Soldering the chips on board A
6) Board A - Top view
7) Connecting MIDI cables

You don’t need the switches, and don’t want to drill your Juno?


You don’t have to drill the Juno’s desk to make the midi wires go out of the synth. I used 2 holes that were already here and it did the trick without any harm on the Juno’s structure :) It is certainly not very sexy, but if you don’t want to drill this is the trick.

8) Keyboard connectors

The retrofit does its magic between the Juno’s keyboard and main board, emulating keyboard messages.

9) Powering the retrofit
10) Job done !

You can now put the retrofit in its dedicated place, and enjoy your fresh MIDI-POWERED JUNO-6 :)

Troubleshooting and support


Support from Mungo (John) has been very helpful when I had some issues making the retrofit work as expected.

Here are some tips I can give:


- if you have the Juno’s keyboard working perfectly thru the retrofit but no action when receiving MIDI, try switching the 2 keyboard connectors, on both the retrofit and the Juno’s main board

- if you have the Juno’s keyboard not working at all, try switching the connectors

- if you have just one or two notes not playing correctly, check carefully the chips soldering

- if you have a range of notes not working at all, check the keyboard cables soldering on retrofit


Hope this has helped you out,



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