F_DRAWCV – Drawable Control Voltage Generator

F_DRAWCV is a trigger-based control voltage generator that lets you draw your own modulation shape. It is designed for creating custom CV movements for filters, pitch, amplitude, effects, stereo movement, ducking, rhythmic modulation, and experimental patch control. Unlike an audio waveform drawing module, F_DRAWCV does not generate audio directly. It generates control voltage based on a user-drawn shape.

Basic Operation

Connect a gate or trigger signal to the TRIG input. Each rising trigger starts playback of the drawn shape from the beginning. The shape is played once over the time set by the LENGTH control. While the shape is playing, OUT A follows the drawn curve and OUT B follows the inverse of the curve. Both outputs have their own bipolar level controls, so each output can be scaled positively or negatively.

Canvas Editing

The large display area is the editable CV shape canvas. The horizontal axis represents time. The vertical axis represents CV value before output scaling. Higher points create higher internal curve values, and lower points create lower internal curve values. The curve itself is always stored as a normalized shape, then converted to voltage by the LEVEL A and LEVEL B controls.

Edit Modes

The EDIT switch selects how the canvas is edited.

• Draw: Drag directly on the canvas to freely draw the CV shape.
• Points: Click to add or move anchor points. The curve is made from straight lines between the points.
• Curve: Click to add or move anchor points and use the square control handles to bend the curve between points.

In Points and Curve modes, double-click an anchor point to delete it. The first and last points cannot be deleted, because they define the start and end of the shape.

Controls

LENGTH sets how long one playback of the shape takes after a trigger. The range goes from very short rhythmic shapes to long slow movements.

SMTH smooths the output voltage. Low values keep the shape sharp and responsive. Higher values round off fast jumps and can make filter or amplitude modulation smoother. For pitch modulation, use low smoothing if you want accurate pitch steps.

LVL A sets the voltage range and polarity of OUT A. Positive values output the drawn curve as positive CV. Negative values invert the voltage direction.

LVL B sets the voltage range and polarity of OUT B. OUT B follows the inverse of the drawn curve before level scaling. This is useful for opposite modulation, such as closing a VCA while opening a filter.

RST resets the editable shape to the default curve.

Inputs and Outputs

TRIG starts playback of the drawn CV shape. A rising signal above the trigger threshold restarts the shape from the beginning.

OUT A outputs the drawn curve multiplied by LEVEL A.

OUT B outputs the inverse of the drawn curve multiplied by LEVEL B.

Typical Uses

• Draw custom filter sweeps.
• Create sidechain-style ducking shapes.
• Generate pitch movement or pitch bends.
• Send opposite modulation to two destinations at once.
• Create rhythmic CV gestures from trigger patterns.
• Use Curve mode for smooth modulation shapes.
• Use Points mode for stepped or angular movement.
• Use Draw mode for quick freehand modulation.

Patch Ideas

Patch a clock, trigger sequencer, or rhythm generator into TRIG. Send OUT A to a filter cutoff and OUT B to a VCA level. With LEVEL A positive and LEVEL B negative, the filter can open while the amplitude ducks, creating strong rhythmic motion.

Patch OUT A to oscillator pitch with a low LEVEL A setting for subtle movement, or a higher setting for dramatic pitch sweeps. Keep SMTH low for accurate pitch shapes, or raise it for glide-like motion.

Use KLIKZ or another trigger pattern module to fire F_DRAWCV rhythmically. This turns the drawn shape into a custom modulation groove.

Notes

F_DRAWCV is meant for control voltage, not audio-rate waveform generation. For drawing audio waveforms, use F_DRAWWAVE. For traditional multi-segment envelopes, use F_MSEG. F_DRAWCV sits between those ideas: it is a drawable, trigger-based CV shape generator for modular modulation.