controlvoltage

Control voltage (CV) is an electrical signal used to control parameters of electronic musical equipment, most notably synthesizers. Unlike audio signals, CV encodes control information as a voltage level, allowing real-time modulation of pitch, timbre, dynamics, and other characteristics. In modular and many semi-modular synthesizers, CV lines run alongside audio paths and are combined in dedicated modules to shape sound.

Pitch CV is the most common use. The standard most often associated with it is 1 volt per octave (1V/Oct). In this scheme, increasing the control voltage by 1 V raises the oscillator’s pitch by one octave. Other scales exist, such as 1.2V/Oct or 2V/Oct, and some vintage gear uses different calibrations. In addition to pitch, CV ranges typically cover non-pitch parameters like filter cutoff, resonance, amplitude, and envelope depth, commonly implemented in ranges such as 0–5 V or 0–10 V. Some systems also support bipolar ranges (for example −5 V to +5 V) for more expressive control. There is no universal standard, which is why many modules include attenuators, offsets, or CV mixers to interface diverse gear.

CV sources include keyboard controllers, sequencers, LFOs, envelope generators, and sample-and-hold circuits. Gate or trigger signals indicate note events, while CV provides the continuous control values. Modern setups often use MIDI-to-CV converters or USB-based interfaces to bridge digital workflows with analog CV equipment.

In contemporary practice CV remains central to modular synthesis, enabling flexible performance and sound design. Effective use relies on calibration and awareness of each device’s input ranges, with protective measures to prevent overloading components.