Voltage Controlled Amplifier

At some voltage level the entire signal is let through.

Voltage controlled amplifier.

The word amplifier is somewhat misleading in this usage. A voltage controlled amplifier vca has two kinds of inputs. Get it as soon as tue jul 7. A vca or voltage controlled amplifier lets you use a voltage to control the amount of another signal that is allowed through to the output of the module.

Most vca circuits do not exceed a gain ratio of 1 meaning that they attentuate rather than amplifying in many synthesizers a vca or a digital equivalent is the last functional block that a signal goes through. This voltage controlled amplifier circuit is simply an op amp having an additional input at pin 5. A voltage controlled amplifier or vca is an amplifier whose gain is set by the voltage level of a control signal. Like it s name suggests it is an amplifier whose amplification or gain is controlled by a voltage.

Carrier signal input this is the input where a bipolar signal comes in. The vca810 is a dc coupled wideband continuously variable voltage controlled gain amplifier. The op amp will use this drop voltage and get the desired 1v feedback. A simple linear voltage controlled amplifier can be constructed with one op amp and two jfets see the figure.

A current ilsc is inserted into this input which controls the gain of the device linerly. Subsequently it is the main signal and all the alterations are made to this signal. Thus by inserting an audio signal 10 mv within pin 2 and 3 and with controlling the current on pin 5 the amount of the signal output pin 6 is controlled. Vcas have many applications including audio level compression synthesizers and amplitude modulation.

Now if we connect a load that requires current control for operation we can use this circuit and place the load at an appropriate location. The amplifier can achieve an 80 db dynamic control range with less than 0 2. Roland 500 series dual voltage controlled amplifier sys 530 tiptop audio voltage controlled amplifier. What is a voltage controlled amplifier.

The device provides a differential input to single ended output conversion with a high impedance gain control input used to vary the gain over a 40 db to 40 db range linear in db v. The detailed circuit diagram for op amp voltage controlled current source can be found in the below image construction. By varying a voltage input we can change the amplitude of a signal making it quieter and louder by supplying a smaller or larger voltage as a control signal. A variable gain or voltage controlled amplifier is an electronic amplifier that varies its gain depending on a control voltage often abbreviated cv.