| Voltage Controlled Amplifier (VCA) | |
| A voltage controlled amplifier accepts a voltage at its input and outputs an increased voltage proportional to its gain setting. | If an amplifier accepts a control signal which alters its amplification characteristics it is a voltage controlled amplifier (VCA). |
| An
amplifier in an analogue synthesizer which changes its amplification according
to the size of a control voltage.
For
example
A transient envelope is often the source of the control voltage. |
| A
varying signal can be used as a control signal for a VCA to acheive amplitude
modulation.
A special case of amplitude modulation is achieved by use of a device which generates a complex function which starts at zero and passes through a sequence of levels at some rate and ends in zero again. When this control signal is applied to a VCA the resulting combination is useful in envelope shaping applications. |