6W+6W Stereo Amplifier Using LA4440

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Here is a simple project of a 6W+6W stereo amplifier using a 14-pin LA4440 IC. This amplifier can deliver an output power of 6W on a 4-ohm speaker (6W each on the left and right channels). The amplifier operates on a 12V power supply.

Except resistors R1 and R2, all the external components used in the circuit are electrolytic capacitors. The author’s prototype is shown in Fig. 1.

Author’s prototypeFig. 1: Author’s prototype

Circuit and working

The circuit diagram of the 6W+6W stereo amplifier is shown in Fig. 2. It is built around LA4440 (IC1), two loudspeakers (LS1 and LS2), and a few other components.

Circuit diagram of the 6W+6W stereo amplifierFig. 2: Circuit diagram of the 6W+6W stereo amplifier

Pin 11 of IC1 is connected to the +12V power supply. The electrolytic capacitor C12 (1000µF/35V) is connected between +12V and ground to act as a filter.

The left speaker (LS1) is connected to pin 10 of IC1 through electrolytic capacitor C8 (220µF/35V). The right speaker (LS2) is connected to pin 12 through electrolytic capacitor C9 (220µF/25V).

A 3-pin connector (CON2) is provided for connecting the audio input signal. The left channel audio input is connected to pin 6 of IC1 through capacitor C1 (4.7µF/35V), and the right channel input is connected to pin 2 of IC1 through capacitor C2 (4.7µF/35V).

Construction and testing

You can assemble the circuit on a 5cm×7cm veroboard or on a PCB whose actual-size layout is shown in Fig. 3 and the components layout in Fig. 4.

PCB layout of the stereo amplifierFig. 3: PCB layout of the stereo amplifier Components layout of the PCBFig. 4: Components layout of the PCB

Download PCB and Component Layout PDFs: click here

First, collect all the components like electrolytic capacitors, resistors, IC LA4440, 3-pin connectors, wires, etc. Then, take a 25-watt soldering iron and solder all the components, as shown in the circuit diagram. Solder a 3-pin connector on the PCB/veroboard for audio input. The middle common terminal of this connector is to be co