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LM386 Audio Amplifier

LM386 is a low voltage audio power amplifier that operates in 4V - 12V or 5V - 22V (depending on package type). It has a controllable gain of 20 to 200 (26dB to 46dB) and an output power of 250mW (at 6V supply and 8 ohm load) or 700mW (at 6V supply and 8 ohm load).

Schematic

Parts List

IC
  U1 = LM386N-1
Resistors
  R1 = 10K potentiometer
  R2 = 1.2K
  R3 = 10 ohms
Capacitors
  C1 = 10uF
  C2 = 0.05uF
  C3 = 250uF electrolytic
Breadboard
Speaker = 8 ohms
Wires (red and black)
Power supply (4-12 V)

Testing

I've tested the amplifier by placing the components in a breadboard and connecting them through jumper wires. It is best to refer to the schematic when connecting the components.

Assembling

Using the provided PCB layout, I've assembled all the components and solder it. A note for placing the components (if you create your own PCB layout) is that components should be placed close to the IC. Here's some photos of the completed LM386 audio amplifier.

Romualdo Dasig's picture