Midi retrofit and feature extension for Polysix, Poly-61 and Mono/Poly (aka. Modysix)

Description | Features | User Manual | Installation Manual | Manufacturing | Order online | Poly-61 notes | FAQ | Quotes


The ModyPoly – successor of the Modysix – is an upgrade for the Korg Polysix, Poly-61 and Mono/Poly synthesizers and features various additional play modes, a free definable arpeggiator, midi in/out, a sustain pedal input and various other features.

Main features

  • Midi in + Midi out
  • Sustain Pedal input
  • NEW: Fully polyphonic Portamento (HiRes Upgrade)
  • Additional play modes: 2 Voice, 3 Voice, Polychord, extended unison mode
  • New arpeggiator / sequencer mode: Powerarp
  • NEW: Mirotuning and custom scales (HiRes Upgrade)
  • All functions are easily accessible via buttons: suitable for live use
  • Midi controls arpeggiator clock, triggers the arp, filter, pitch bend * and more
  • Midi output of arpeggiator, chords and powerarp sequences or simple keypresses
  • S/H LFO and fast triangular LFO for filter
  • Midi channels and various other options can be configured without external tools
  • Very easy to install, no soldering required (a bit of soldering if you want midi controlled filter and pitch bend)
  • High quality midi sockets and sustain pedal jack
  • For a complete list of features please refer to the user manual.

* Pitch bend Polysix and Mono/Poly only.

final promo web

Some features in more detail

2 voice and 3 voice

While the original Polysix only features 6-voice polyphonic, unison and chord memory, this mod adds additional play modes.2-voice and 3-voice polyphonic modes are tradeoffs between the maximum fatness of the unison and the maximum number of voices of the polyphonic mode.
The Mono/Poly gets updated with 2-voice and 3-voice modes and two exciting random modes.


Polychord lets you assign a chord consisting of up to 6 notes to any key of the keyboard. This can be done very quickly and is very suitable for playing live. Of course you can combine this feature with the normal arpeggiator or the powerarp (see below). This makes it possible to have a sequenced chord progression in the matter of seconds.

extended unsion mode

The unison mode on the Polysix is basically a monophonic mode, but lacking almost all of the features that most monophonic synths have.The extended unison mode this modification offers changes that.
– legato mode (no envelope retrigger when playing legato)
– key priority up / down / last
(Poly-61 users see Poly-61 notes)



Powerarp is a feature best described as a sequencer or a custom arpeggiator.
You can define a sequence of up to 128 notes, which are then triggered by the arpeggiator clock. Up, down, updown and three different random modes are just a few ways to replay this sequence. You can use this with all play modes including Chord and Polychord, which means you can define complex chord progressions and replay them using the arpeggiator, an external trigger or using midi. You can also add breaks into the sequence which allows rhythmic arpeggiator sequences.


Installation manual

Installation of the ModyPoly is very simple. It is a direct replacement for the “Voice assigner” processor of the Polysix, Poly-61 and Mono/Poly. No soldering is required here. To install the midi and sustain sockets you have to drill a few holes in the back of your synthesizer and if you want the optional midi to filter and pitch bend control you have to solder a cable.

If you don’t want to install the mod yourself, check out our list of synth techs all around the world.

Please read this disclaimer before installing the mod.
Installation manuals can be found here:
ModyPoly rev3 installation manual for Polysix (newest version)
ModyPoly Installation Manual for Korg Polysix (old rev2 version)
Manual de instalación para Polysix en Español (old rev2 version)

ModyPoly Installation Manual for Korg Poly-61

ModyPoly rev3 installation manual for Mono/Poly (newest version)
ModyPoly Installation Manual for Korg Mono/Poly (old rev2 version)

If you install the HiRes version, please read the HiRes installation manual.



The ModyPoly is designed an manufactured in Germany.
Only lead free components and solder are used.

Order online

ModyPoly can be ordered online here in our shop. We ship from Germany with fixed shipping costs worldwide. If you want us to install the mod for you please contact us.

Tubbutec ModyPoly

Midi retrofit and feature extension for Polysix, Poly-61 and Mono/Poly.

Fully assembled retrofit with high quality midi and sustain sockets.
Also includes a stencil for drilling the holes and a sticker for labeling.

Order at Tubbutec Shop

final promo web


Additionally overlays for ModyPoly are available. They serve as an easy lookup table for the internal config menu.
The overlays work for Polysix, Poly-61 and Mono/Poly and are white on black.
For the the Polysix and Mono/Poly the strip fits perfectly on the front lip of the top panel. The Poly-61 version is mounted on the top panel.

Order at Tubbutec Shop

final promo web

Tubbutec ModyPoly installed by us

Midi retrofit and feature extension for Polysix, Poly-61 and Mono/Poly.

We install the ModyPoly for you. We are based in Berlin and you can either bring or send us your Synth.

Contact us

Polysix Push button replacement

A lot of Polysix’s I worked with had worn or even broken push buttons. As the ModyPoly mod makes use of five Polysix buttons (POLY, UNI, CHORD, HOLD, ARP), the workflow will also be dependent on the quality of these. If your buttons are sticky or very hard to push, I recommend replacing them.

Replacing is fairly easy but requires some soldering. Multiple how-to’s are available in the net.

Replacement buttons can be ordered in the Tubbutec Shop


Poly-61 notes

The ModyPoly works identically for the Polysix and the Poly-61, however due to the Poly-61 beeing DCO based there is no detuning between the six voices. For this reason it did not make sense for Korg to implement a unison mode into the Poly-61 and consequently it does not have a unison button.

As a result it is not possible to select unison, 2 voice and 3 voice mode by using the synthesizer’s interface. Even though it does not make sense to use 2 voice and 3 voice modes with a DCO based synthesizer (you just get less voices, but not the advantage of a ‘fatter’ sound), the extended unison mode offered by the ModyPoly might be interesting for some users for its emulation of classic monophonic synthesizers.

There are three ways to still use the unison mode with a Korg Poly-61:
– Use chord memory with up to six layered oscillators instead: Press hold ans play the same note multiple times. Then use it as Chord Memory.
– Select unison play mode by using midi (See the manual for how to do this)
– Install a unison button (and led). See manual here.


Photos by Krunwerke


  • Q: Do you lose any features by installing the mod ?
  • A: No, great care has been taken to maintain and emulate the behaviour of the original synths. All added features are additional to the existing ones.
  • Q: I know some electronics and I want more features!
  • A: Check out the Mod-Modysix post in our blog. There are some instructions for advanced users who can’t get enough of their ModyPoly
  • Q: Does this have midi controlled pitch bend?
  • A: Yes. but you need to solder some components, see the construction manual for details
  • Q: Does this work for the Poly-61M?
  • A: Yes, see Poly-61M installation guide for details

If you have any questions, do not hesitate to contact us.


Für den Preis ist [Modysix] sicher die beste Erweiterung, die man dem Polysix schenken kann.
Translation: For the given price [Modysix] is certainly the best extension one can give the Polysix. [Synthmag #46, Sept/2014]

Wer einen Polysix hat und ihn liebt, sollte mindestens über Modysix nicht nachdenken, sondern sofort einbauen.
Translation: Anyone who owns a Polysix and loves it should at least not think about the Modysix, but install it.[Synthmag #46, Sept/2014]

I’ve purchased the Modysix for my 61. Shipping was inredibly fast. The customer advisory service was quick and very helpful and most of all particularly fair in exposing the pros and cons of the product. Modysix costs more than one competitive product and less than another, but to my opinion it is worth every cent of its price. The built in features seem to be designed with regard to the musician’s actual needs. Grandpa 61 got its rejunenation and he now plays major leaque again, along with nowadways flagships, at least in my opinion and my ears. No desire for Andromeda or Prophet ’08 anymore.[Markus Hahn, Tubbutec Blog]

Alle Geräte aus! Nur den Polysix und gemütlich bei einer Tasse Tee einen kompletten Song schreiben _und_ programmieren.
Ich liebe es wenn man mit einem elektronischen Instrument so ‘privat’ arbeiten und dabei trotzdem voll ausholen kann.
Translation: All gear off! Writing _and_ programming a whole song cosily with Polysix only and a cup of tea.
I love it when one can work with an instrument in such a ‘private’ way still can go over the top
[Norman Hecht, Nachtzug (Polysix and Poly-61)]

All well installed, was extremely easy to do. From the manual I had already appreciated the thoughtfullness that went into this modification, and now that I can use it I can only say: what an amazing creative expansion of the great Polysix! That mega powerarp alone would be worth it already, blows all other synths away! Big thanks!![mail from customer]

… I highly recommend it. Reasonably priced and you can install it yourself with little technical knowledge. The midi alone is worth the price but you also get super cool sequencer features for the arp and more. The designer/seller was very friendly and helpful …[Electronaut Forum]

I’ve got the Modysix installed and running in my Polysix. Absolutely brilliant kit with a very easy and elegant install (the hardest part was drilling the holes). The Polychord and Powerarp features are my favorite features as I enjoy trigger based sequencing (ala SH-101 and JX-3P). This is going to expand the usefulness of the synth so much in my studio.[mail from customer]

All well installed, was extremely easy to do. From the manual I had already appreciated the thoughtfullness that went into this modification, and now that I can use it I can only say: what an amazing creative expansion of the great Polysix! That mega powerarp alone would be worth it already, blows all other synths away! Big thanks!![mail from customer]