Introduction: Simple Audio Amplifier With LM386

About: Electronics Enthusiast and a Software Engineer

The LM386 is quite a versatile chip. Only a couple resistors and capacitors are needed to make a simple audio amplifier. The chip has functions for gain control and bass boost, and it can also be turned into an oscillator capable of outputting sine waves or square waves.

The LM386 is a type of operational amplifier (Op-Amp). Operational amplifiers have a basic task. They take an input potential (voltage) and produce an output potential that is tens, hundreds, or thousands of times the magnitude of the input potential. In this circuit, the LM386 takes an audio input signal and increases its potential anywhere from 20 to 200 times. That amplification is what is known as the voltage gain.

Step 1: Components Required

Power supply(9v)

resistor - 10 ohm

capacitors - 0.1uf , 1000uf

LM386 IC

Potentiometer (variable resistor) -10k ohm



Battery snap

Step 2: Circuit

Step 3: Implementation

Place LM386 ic on breadboard .

Connect battery snap to bread board.

Connect pin2 and pin4 of lm386 to ground

Connect a 10ohm resistor to pin5.

Connect another terminal of 10ohm resistor to 0.1uf capacitor and another terminal of 0.1uf capacitor to +ve terminal of 9v battery.

Connect +ve terminal of 1000uf capactor in between 10ohm resistor and 0.1uf capacitor.

Place potentiometer on bread board.

connect pin3 of lm386 to middile pin of potentiometer.

connect third terminal of potentiometre to ground.

Now connect 3.5mm audio jack L/R pin to first pin of potentiometer.

Ground terminal of 3.5mm jack to circuit ground.

connect +ve termnal of speaker to -ve terminal of 1000uf capacitor and -ve terminal of speaker to ground.

short pin1 and pin8 of lm386.

connect pin6 of lm386 to +ve terminal of the battery.


For more info about circuit you can go through the video below.

Step 4: Datasheet

Step 5: Circuit Demonstration and Testing

Maker Olympics Contest 2016

Participated in the
Maker Olympics Contest 2016