Tubbutec ModyPoly User manual

Tubbutec ModyPoly
Midi retrofit and feature extension Rev.3
Installation Manual for Korg Polysix
http://tubbutec.de
N TE: this is the installation manual for ModyPoly Rev.3.
You can find the text ’rev3’ on the bottom of the ModyPoly
chip!
Tools you will need:
•Soldering iron
•Metal drill 3.2mm (or similar)
•Metal drill for a 15mm hole (stepping drill for example)
•Center punch
•Screw driver
Included in the kit:
•ModyPoly chip
•34K and 68K resistors
•Midi socket drill guide
•4x M3 bolt, 4xM3 nut for midi sockets
•Sticker for midi socket labelling

Installation
The ModyPoly is a drop in replacement for the ”key assigner” IC and thus
very easy to install. Just plug and play basically. Three holes for the midi
sockets and the sustain pedal jack have to be drilled in the back of the
Polysix and if you want to be able to control the filter via midi there is
one cable to solder. Midi pitch bend requires soldering of two resistors.
Important: Before doing any of the steps below unplug the Polysix´s
power chord!
Opening the Polysix
In order to open the Polysix you have to take out the four screws in the
corners of the front panel and four screws on the underside of the synth.
You can then open the front panel.
Installing the jacks
Use the stencil provided to mark the location of the seven holes for the
midi connectors and the sustain jack. You can choose any location for
these holes. We recommend to remove the serial plate beside the power
connector and drill the holes there. This way, if you ever want to remove
the connectors for some reason, you can cover the holes with the plate.
Alternatively we offer a new rear panel for the Polysix which has the
holes for the jacks already drilled. It also has a C14 power cable
connector to get rid of the non-detachable power cable.
The DIN connector with three cables is for midi out, the one with two for
midi in and the jack for the sustain pedal. A drill aid for the connectors
and a sticker comes with the kit. Use the four black M3 screws and nuts
provided to mount the midi sockets. The recommended way to do this is
from behind, so you do not have to resolder the wires.

Installing the ModyPoly chip
First remove the keyboard to access the key assigner IC. To do so,
unplug the connector coming from the keyboard, then remove the
screws on the bottom of the Polysix and remove the keyboard.
In order to install the processor board you have to remove the existing
processor (IC6 D8049C 217) and replace it with the ModyPoly chip. You
can use a small screw driver to carefully lift the processor out of its
socket. When putting the ModyPoly chip into the socket, mind the
orientation (cables are on the right side) and be careful not to bend any
pins.

Soldering the filter wire
If you want to be able to control the filter via midi, you will have to
solder one cable to the leg of a resistor (R51) on the back of the voice
board (KLM-366B) as shown in the picture. The cable is the orange wire
coming from the ModyPoly board.

Soldering the pitch bend wire
In order to add midi controlled pitch bend to your Polysix you need two
resistors, one 68k one 34k. ther values are also possible, as long as
one has double the value of the other. This will change the maximum
pitch bend range. Smaller values will increase the range. The resistors
need to be soldered onto board KLM-367A as shown in the picture.
Solder the red wire to the free leg of the 34k resistor. Some heat shrink
is recommended here.
Pitch bend calibration
After installing the pitch bend resistors, the pitch bend CV needs to be
calibrated due to part tolerances. To perform pitch bend calibration set
the tune knob to the center position, make sure the pitch bend wheel is
at center and then use midi to send midi pitch bend messages until the
synth is in tune. While it is in tune switch into the config menu (press
H LD until it starts blinking) and press ’pitch bend cal’ (The second
hightest key on the keyboard) to save the current setting as the new
pitch bend center position. Exit the config menu by pressing H LD again.
That’s it. Have fun.