vca

vca · utilities · schema v1

Voltage-controlled amplifier. Multiplies the audio input by base + (cv * cvAmount).

A voltage-controlled amplifier that multiplies an input audio signal by a gain factor computed from a base DC offset and CV control voltage scaled by the cvAmount parameter. Mental model: the VCA's output amplitude is set by patching a CV signal into the CV input (typically an envelope or LFO) and tuning the base knob for silent-when-unpatched (0) or passing audio-through at unity (1). A phase-inverted copy of the output is always available on the audio_inv port for stereo widening, sidechain processing, or mid/side decomposition without needing a separate inverter module.

the faceplate

2 inputs · 2 outputs · 2 params

inputs

id	cable	what it does
`audio`	audio	The audio signal to be amplified or gated; typically a voice from an oscillator, sampler, or other sound source. audio signal
`cv`	cv	Control voltage that modulates the gain amount; combined with the base parameter and scaled by cvAmount to set the overall amplitude. Typical sources are envelope generators (ADSR), LFOs, sequencer CV outputs, or other modulation sources. control voltage (CV)

outputs

id	cable	what it does
`audio`	audio	The amplified audio signal, computed as audio × (base + cv × cvAmount). When base=0 and nothing is patched into CV, the output is silent; with base=1 and cv=1 (unity gain), the signal passes through unchanged. audio signal
`audio_inv`	audio	A phase-inverted (180° flipped) copy of the audio output, useful for stereo width techniques, preventing feedback in sidechain chains, or mid/side processing. audio signal

params

id	label	range	default	curve
`base`	Base	0..1	0	linear
`cvAmount`	CV	-1..1	1	linear

controls

control	what it does
Base	A static DC offset added to the CV signal (linear 0 to 1, default 0). Set to 0 for silent when unpatched; set to 1 for unity gain. Typically used as a quick volume control or to set the VCA's baseline attenuation.
CV	Controls the scale and sign of the CV input (linear −1 to 1, default 1). Positive values amplify normally; negative values invert the CV so a high incoming signal produces low gain. Useful for inverting modulation or creating sidechain-style ducking effects.

source

vca.ts on GitHub.