All audio amplifiers have some mechanism to increase and decrease volume. Most such mechanisms involve mechanical parts like a potentiometer. Here this project is to create an audio controller that works digitally. This is a very simple project which uses two switches and an IC to electronically control the audio output from an amplifier.

Digital Volume Control Circuit

This is the circuit diagram of a digital volume controller for any sort of audio amplifiers or almost any circuit where a mechanical potentiometer is there(conditions apply). Simple and low cost, the heart of the circuit is DS 1669 digital potentiometer IC from Dallas Semiconductors. The circuit has no external components other than two pushbutton switches and a capacitor.


S 1 increases the volume & S2 decreases.

The input audio signal must be not less than -0.2 Volts.

If some clipping problem occurs, use a dual power supply of +5 & -5V.( Not shown in the figure).In this situation connect +5V to pin 8 & -5V to pin5 of IC DS1669.

If you like to build other audio circuits, you may try our 3 channel audio splitter circuit. Another circuit I can recommend is a stereo sound level indicator. You may also try to build this active crossover circuit.

Volume controller Circuit Diagram

Volume Control Circuit

Pin assignment & description of DS1669

DS1669 IC Pin Configuration

Audio circuits are very important in learning communication engineering. You gotta learn how filters work, noise reductions, application process and successfully transmitting the audio signals over a network. Learning audio circuits requires good patience. You may not get the first few projects in the right way. What I suggest is, you just keep going. Eventually, you will learn the fundamentals and get everything right.




    What is the layman’s value of the capacitor and show the simple discription

  2. saritha p a

    a single pulse width input over the UC Dc and D terminals will cause the wiper position to move 1/64 of the total when we connect swich in tha UC and DC terminals ,we have to press 64 times to reduce the volume to min and vice versa… how can we reduce this much delay in incerasing and decresing the volume…?????