Wide dynamic range gain control amplifier circuit diagram

The wide dynamic range gain control amplifier circuit is shown in the figure below. Experience has proven that when using FET as a variable resistor to control the gain of the amplifier, when the input signal is 1% of the pinch-off voltage, there will be 1% distortion. If two resistors and a field effect tube are used to form a T-shaped network in the feedback loop, the signal is attenuated by R1 and R2 and then added to the field effect tube, so a considerable signal can be controlled.

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