Optional Modifications - Korg POLYSIX M Owner's Manual

3) OPTIONAL MODIFICATIONS

Besides MIDI there are following features on the MIDI pcb:
A) White Noise generator (programmable level):
• Solder the free ends of cable drawing no. PS 6M 00 05 003 to the "upper" end of R150 of each unit on KLM-
366 (refer to drawing). It is possible that noise is enabled in your patches. It is disabled when waveform PWM
is selected or when PWM SPEED setting at '0'.
B) Waveforms Sawtooth and Pulse appearing simultaneously:
• Remove D1 from KLM-366.
Note: When Saw is selected the pulse wave is generated, too. To switch off the pulse wave turn the PW knob
fully clockwise ('10'). You have to check and reprogram your patches after this modification.
C) Programmable BEND wheel (selectable VCO or VCF bending).
On KLM-370 the EFFECTS MODE switch (OFF/CH/PH/EN) has to be coded onto two data bits:
• Remove D3.
• Mount two diodes (1N4148, supplied):
• D3A: anode to D1/anode; cathode to former D3/cathode
• D3B: anode to D2/anode; cathode to former D3/cathode
(cathode side is marked with a black ring).
Obtain signals from KLM-367 for decoding EFFECTS MODE:
• Desolder IC34 (4042) an replace with supplied DIL16 IC socket. Desoldering in best done by cutting each leg
of the IC and then removing each leg separately.
• On the wheel panel (e.g. above BEND Wheel) mount BEND Mode switch:
• Drill a hole (6.5mm / 1/2") and mount switch connected to cable PS 6M 00 05 005.
On the jack panel (at the rear):
• Disconnect orange wire from fcM In jack (you will loose this input in this case; it can be used for a modulation
pedal input, see below). Solder a single pin onto the end of this wire and put a piece of shrinking tube over it.
This single pin will be used to connect to the orange wire of cable PS 6M 00 05 005, which has a single
receptacle on its orange wire.
On KLM-366:
• Remove R50 (100k), R51 (150k), and C58 (0.01u).
• Cut pcb trace IC10/pin1 to (former) R50.
• Connect former R50/"upper" pin to former R51/"upper" pin.
Note: If you want to keep the fcM input, you have to connect the orange wire of cable PS 6M 00 05 005 via an
additional 33k resistor to KLM-366/IC13/pin2 instead (this is the summing node of the VCF cutoff frequency
control voltages). Additionally do not remove R50, R51, and C58 from KLM-366.
You will have to check and maybe reprogram the EFFECTS MODE setting of your patches.
If you do not want the BEND Wheel be programmable and leave the EFFECTS MODE as it is, do not
perform any of these modifications. Instead you have to remove the connection pins labeled J6 from the MIDI
pcb (solder side).
D) Modulation Pedal In jack:
On jack panel assembly:
• Replace the fcM In jack (see above) with supplied stereo jack connected to cable PS 6M 00 05 006 (you will
loose the fcM In function).
• Connect GND wire to neighboring jack (Arpeggio Trig In).
E) Make the BANK LEDs A-D equally bright when more than one LED is on:
On KLM-371:
• Remove R14 (470 Ohm), J12, J13, J16 (0 Ohm)
• Mount 0 Ohm or wire bridge into R14 location.
• Mount 470 Ohm into J12 location.
• Mount 470 Ohm into J13 location.
• Mount 470 Ohm into J16 location.
F) If you experienced the headphones being too loud you may replace KLM-368/R4 and R8 (1k) by 3k3.
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