LM386 Audio Amplifier





Introduction: LM386 Audio Amplifier

I wanted to design an audio amplification circuit for a future project so i just wanted to design this one for now so i get an understanding of how it works. This is a very basic circuit that you can find all over using an LM386 integrated circuit i got from RadioShack.

Step 1: Obtain Parts

All Components can be found at RadioShack.

Multipurpose PCB with 417 Holes
5-15 Volt DC power supply (4 AA or 1 9v Battery)
8 Ohm Speaker
Audio Source e.g. iPod
8-Pin Retention Contact
IC1    IC                           LM386 Audio Amp IC
R1     Resistor               10 Ohm
R2     Resistor               1K Ohm
R3     Potentiometer     10K Ohm
R4     Resistor               10 Ohm
C1     Capacitor             220 Micro Farad
C2     Capacitor             10 Micro Farad
C3     Capacitor             220 Micro Farad

Step 2: Place Components

Arrange components the best you can using the wiring diagram. i placed them as close together as i could, but it may be easier to spread them out a little more or breadboard this circuit first.  I highly suggest breadboarding first just to get a feel of the arrangement, prior to soldering.

Step 3: Observe Diagram

Look through the wiring diagram to see what components need to be connected to what prior to soldering.  This is a basic wiring diagram, one of a hundred I found online, very basic. The one i used was from this website http://www.rason.org/Projects/icamps/icamps.htm.

Step 4: Solder Components

Solder components carefully to ensure there are no shorts, also ensure all connections are made at all points.

Step 5: Clean Up and Test

Trim component leads and clean solder joints. Be sure to double check connections to make sure a connection isn't left out.  Hook up a 5-15 Volt DC power supply, your audio source, and 8 Ohm speaker and test it out.  Be sure to ground out the audio sources audio low line and ground out the speakers ground wire to the circuits ground.

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167 Discussions

How do i make it for 2 speakers(L & R) ,Do I have to make 2 of them?

c1 220 uF with batery ,,what is the function ??

Can I use an nte823?

hii ..can you suggest a different ic tht can produce a 1-2 watt output


2 years ago

Just a little question, the R4 resistor wasn't supposed to be placed before C3? I mean, at some point, the 220uF electrolytic will charge and won't allow the current to flow, right?

This may be a dumb question but where do i connect the battery's positive and negative terminals specifically?

1 reply

great and simple amp. Thanks for sharing. Room for probably a stupid and repeated question? How much current / power could this amp drive?

Pot on the output seemed to work better for me

Quick question, and hopefully not a stupid one. How do I connect the audio input to this circuit? What kind of cord should I use? I have tried using a 2-wire cord and grounded the black cord, using the red as the input. That gave me some sound with lots of garbage. I spliced a set of earbuds and have a red, black, and green wire. Would this work? Please somebody help!

1 reply

green is left red is Right black is grond.

Connect green and red to the input pin and black to ground and that should work

I think it'll work, but it'll draw more current than 8 ohm speakers for the same volume, since this amp is made for the latter

I actually have an application for the noise. Please tell me how to use pin 5 to aggravate the noise.