User manual

Square wave output. It has a level of +/-5 volts centred around 0v. The duty cycle

(amount of time the waveform is “high” against “low”) can be varied with the Manual

PWM control (15) or under voltage control (16). The output impedance is 1Kohm.

A control voltage can be applied to the PWM CV Input to vary the PWM duty cycle. The

control voltage range should be between +/- 5volts and the intensity can be controlled

between 0% to 100% with the PWM CV rotary control knob. A low frequency triangle

wave to the PWM CV Input will give the classic sweeping PWM eect. The PWM Shape

Control is still eective when using PWM CV and it changes the oset level.

Power Cable

A Tune Adjust :

Sets the default frequency for the VCO. This is a multi-turn trimmer that should be

adjusted with a ne jeweller’s screwdriver. Turn counter clockwise to increase VCO pitch

and clockwise to reduce the pitch. Adjusting this trimmer will not aect the scaling.

B Scale Adjust :

C Octave Adjust :

D HFT Adjust :

FOR MANUFACTURER ADJUSTMENT ONLY. Specialist test equipment is needed to

calibrate this trimmer correctly.

E Shape Adjust :

FOR MANUFACTURER ADJUSTMENT ONLY. This sets the current level through the

P-FET transistor buer and incorrect adjustment can halt the Oscillator completely, so

NO ATTEMPT should be made to adjust this trimmer.

Note:

This information is given for completeness, the MiniMod VCO is calibrated after manufacture

and under normal circumstances should not require any user adjustment.

Adjustment and Calibration

C Octave Adjust HFT Adjust D

Shape Adjust E

Red Stripe aligns with -12V as shown

Scale Adjust B

A Tune Adjust

If you need any help using this module or have any technical questions please feel free to

FOR MANUFACTURER ADJUSTMENT ONLY. Sets the span for the Octave Select Switch.

Specialist test equipment is needed to calibrate this trimmer correctly.

FOR MANUFACTURER ADJUSTMENT ONLY. Sets the V/Oct scaling for the VCO. Specialist

test equipment is needed to calibrate this trimmer correctly.