Voltage Controlled Amplifier – VCA

This  is a Voltage Controlled Amplifier (VCA). A VCA board helps users control the Audio Level from a remote potentiometer. It requires a single-ended audio signal in the input. Gain control voltage can be adjusted through an on-board potentiometer or use an external potentiometer connected to CN4. The project works with a dual ±15V power supply. Screw terminal connectors are provided for signal input and signal output. The project is built using THAT2181LA chip, a VCA that is designed for high-performance audio-frequency applications requiring exponential gain control, low distortion, wide dynamic range, and low control-voltage feedthrough. These parts control gain by converting an input current signal to a bipolar logged voltage, adding a DC control voltage, and re-converting the summed voltage back to a current through a bipolar antilog circuit. Stereo control of VCA with a single potentiometer is possible.