LM386 Audio Amplifier Circuit with Proteus Simulation

LM386 Audio Amplifier circuit is used in small battery operated audio devices like radio, audio players, etc. It is manufactured and design by Texas Instruments. LM386 is widely used for audio amplifier as it is specifically designed for low power applications. We will simulate the LM386 audio amplifier circuit using proteus simulation software. The circuit provided is tested and can be easily implemented. LM386 provides adjustable gain (a volume changing button) which helps to adjust amplification factor.

Know more about LM386 in Datasheet.

Internal Diagram of LM386 Audio Amplifier:

LM386 Audio Amplifier internal diagram
LM386 Audio Amplifier internal diagram

The default gain of the LM386 Audio Amplifier is 20 because of the 1.35K resistor attached internally between the 1st and 8th pin. The gain can be adjusted between 20 to 200 by connecting a RC circuit between the 1st and 8th pin.

Typical diagram of LM386 Audio Amplifier.

LM386 Audio Amplifier typical diagram
LM386 Audio Amplifier typical diagram

This is a basic diagram for the gain 20. Nothing is connected between 1st and 8th pin.

Complete Circuit Diagram of LM386 Audio Amplifier.

LM386 Audio Amplifier Complete diagram
LM386 Audio Amplifier Complete diagram


  • LM386 supply
  • 10K Pot
  • Speaker
  • 1uf Capacitor
  • 47nf capacitor
  • 10K resistors
  • Powersupply
  • Proteus Components Snap:

Select the below components in proteus.

Audio Amplifier Components
Audio Amplifier Components

Important Connections in proteus.

  • At input select Generator from left panel and Select Audio and connect it.
  • At output we have connected a speaker
  • From left panel select the probe and connect at input and output sides.
  • From left panel select graph and select Audio. Drag in the main screen.
  • Select two graphs as we will require for input as well as output.
  • Right click on graphs and click on Add traces. Select probe for each graphs respectively.
  • At input audio right click and choose your .wav file. I have used bird.wav file. You can download from here: Bird.wav

Final Simulation of LM386 Audio Amplifier circuit.

  • Right click on first graph and click run simulation. You will see a graph of your input audio waveform
  • Right click on second graph and click run simulation. You will see a graph of your amplified output waveform. 

Output Graphs:

Input Audio:

LM386 Audio Amplifier Input Audio waveform
Input Audio waveform

Amplified Audio output:

LM386 Audio Amplifier Amplified Audio output window
Amplified Audio output window

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  1. Hello, I am trying to simulate a simple 3-band graphic equalizer circuit in Proteus 8 Professional.
    There are no errors in the circuit, but all I get at the output speaker is Burst Noise. A warning also pops up saying that Simulation is not working in real time due to excess CPU load, although the CPU load is only 3% to 4%. Can you please help? Thanks! The speaker I have used is
    Device- SPEAKER, Library- ACTIVE, Description – Loudspeaker Model (Analog – Outputs via Sound Card).
    Thanks! 🙂

    • Hi Parth, sometimes Proteus and other simulations doesn’t work properly as they move into unconditional area due to complexity of the circuit. If you are sure with your design you can go ahead with your circuit implementation. You can share the proteus file and circuit schematic so I can moderate it and get back to you. Share at elexfocus@gmail.com


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