Control voltage
The Control Voltage , German control voltage , is used in analog synthesizers and especially the modular synthesizers to control the various parameters of a sound. The technology, also known by the abbreviation CV / Gate , is used to control, for example, on / off, pitch, volume and the degree or quality of the filtering.
This principle was systematically introduced and successfully disseminated with the sale of Robert Moog's synthesizers . But numerous other devices such as Arp synthesizers, Korg MS10 / 20, EMS and Crumar are also proficient in this technology. With patchbays you could freely interconnect everything with some devices.
In the 1980s, this analog control method was largely replaced by the introduction of the MIDI protocol. With the advent of digitalization, the corresponding musical instruments disappeared for the time being, but received a brief revival in the techno era in the 1990s. Here in particular through the Roland TB-303 . Various stage lights could also be controlled via CV / Gate, such as stroboscopic lights.
A big advantage of the analog control is the high resolution. While MIDI with 7 bits only offers a resolution in 128 steps, an analog resolution is almost infinite. Another big difference is that the control voltage does not differentiate between control and audio signals. Audio signals can thus be used as control voltage and vice versa. Under MIDI, these are divided into separate worlds.
Nowadays, modern software synthesizers such as Reason make it possible to simulate analog control of virtual modules, for example in order not only to switch a note on and off, but also to determine the velocity.
In 2009, Mark of the Unicorn (MOTU) released Volta, a virtual instrument as a plug-in that enables precise control of voltage-controlled instruments via music software .