9720 Voltage Controlled Oscillator:
1. Increase range of Pitch knobs. (will now go from subsonic to ultrasonic).
Remove 390k resistors from R17 and R41. Replace with 100k resistors.
2. Stop Modulation from controlling Osc B Pulse Width.
Cut wire connecting J18 to J10. This is the wire between the Modulation out jack and the PW jack.
3. Stop P1 Glide input from controlling Osc B.
Cut wire connecting J5 to "X" on circuit board. J5 is the OSC B, P1 jack.
9730 Voltage Controlled Filter:
1. Increase range of Frequency knobs.
Cut ground wire from pin 3 of pots R86 and R88 ("Freq" knobs). Attach 10k resistors here. Connect other ends of resistors to pin 3 of pots R85 and R87 ("Q" knobs). So, R86 pin 3 resistor to R85 pin 3, R88 pin 3 resistor to R87 pin 3. Be sure to reconnect ground wire for nearby jacks. Then, replace R47 and R48 with 10k resistors.
Note for this mod: with a high cutoff setting, a high control voltage may create a loud noise burst which may freeze the unit and require a power off.
2. Stop Modulation from controlling frequency.
Cut wire that goes from pin 2 of pot R89 (Modulation Output) through 2 resistors on to J9 and J12 ("Fc1") switch lugs. You can remove the resistors if you want.
3. Stop Fc2 of Filter A from controlling Fc2 of Filter B.
Cut wire connecting J10 and J13 ("Fc2").
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