A voltage-controlled amplifier is an electronic amplifier that varies its gain depending on a control voltage (often abbreviated CV). An electronic amplifier is a device for increasing the power of a signal. ... Electronics In electronics, gain is usually taken to meaning the ratio of the signal output of a system to the signal input of the system. ...
They have many applications, including audio level compression, synthesizers, and amplitude modulation. Note: This article is about audio level compression, which reduces the dynamic range of audio signals. ... The term synthesiser is also used to mean frequency synthesiser, an electronic system found in communications. ... Amplitude modulation (AM) is a form of modulation in which the amplitude of a carrier wave is varied in direct proportion to that of a modulating signal. ...
A crude example is a typical invertingop-amp configuration with a light-dependent resistor in the feedback loop. The gain of the amplifier then depends on the light hitting the resistor, which is provided by an optocoupled LED. The gain is then controllable by the constant current through the LED. This is the type of circuit used in "optical" audio compressors. An operational amplifier or op-amp is an electronic circuit module (normally built as an integrated circuit, but occasionally with discrete transistors or vacuum tubes) which has a non-inverting input (+), an inverting input (-) and one output. ... An operational amplifier or op-amp is an electronic circuit module (normally built as an integrated circuit, but occasionally with discrete transistors or vacuum tubes) which has a non-inverting input (+), an inverting input (-) and one output. ... A photoresistor is an electronic component whose resistance decreases with increasing incident light intensity. ... Various light-emitting diodes (5 mm reds, 3 mm greens and yellows) A light-emitting diode (LED) is a semiconductor device that emits incoherent monochromatic light when electrically biased in the forward direction. ...
External links
Examples of non-optical VCAs (http://www.uni-bonn.de/~uzs159/vca.html)
Has some schematics for VCAs (http://www5b.biglobe.ne.jp/~houshu/synth/)
The amplifier is programmably adaptable through the use of a monolithic programmable switch array using, for example, semiconductor fuseable link technology to preset digital-to-analog converters voltagecontrollable levels of the amplifiers and compressors of each channel according to a digital control input.
The outputs of the second voltagecontrolledamplifier 88 are mixed into a single channel, for example, at the input to a buffer amplifier 90, and fed through an output line 56 to the output amplifier 14 and thereafter to a speaker 16.
The voltage signals for controlling the amplifiers 80 and 88 and the compressor 84 are generated by the coefficient selector 34.
Feeds |
Contact