A Simple Audio Amplifier With Dual Power Source


This simple audio amplifier can be built at home with just a few components. You can use it at home or in a car with a 12V car battery as the power source. The author’s prototype is shown in Fig. 1 while the circuit diagram is shown in Fig. 2.

fig.  1: Author's prototype of a breadboard
fig 1 Authors prototype of a breadboard

The circuit consists of step-down transformer X1, bridge rectifier BR1, 12V voltage regulator IC LM7812, amplifier IC LA4440, 20W loudspeaker LS1, and other components. Capacitors C1 and C7 connected to the supply terminals are used to reduce signal ripples / noise.

Download PCB and Component Layout PDFs: click here

This project will be published in a few weeks. If you want to access it now, check out Electronics For You’s December 2022 Issue–print or ezine edition.

SC Dwivedi is an electronics enthusiast and circuit designer of EFY


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