Introduction: LM386 Audio Amplifier

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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.

Comments

KevinH294 made it! (author)2016-10-10

Really nice proyect! It worked.

I've used 9v but hasn't checked other voltages.

I leave you guys here a photo of the circuit and the lay out i've made (the terminals of the trimpot are not placed in the same place as the lay out but i've adapted it).

S73L105 (author)KevinH2942017-06-16

The volume controller i have has 6 prongs. How would I wire that in?

KevinH294 (author)S73L1052017-06-19

Hi! You need to look for the datasheet of that volume controller. I'm sure that is disposed in two rows of three pins, right? If that's the case, i think you can connect the volume controller with one row of three pins like i do.

SirCooksalot (author)KevinH2942016-11-30

Hi, can you please help me? Couple of questions: What does the pot adjust? And, what are the pins for? (You have a 2-pin [far left] and 4-pin [far right] jumper). Thanks for everything!

KevinH294 (author)SirCooksalot2017-02-23

Hi SirCooksalot.
The pot adjusts the signal voltage that enters into the circuit. In other words, adjusts the volume.
The 2-pin is the power and the 4-pin is the input+output. You can see i put the names on it.

KevinH294 (author)SirCooksalot2016-11-30

The pot adjusts the volume. In the lay out says what are the pins for. You just need to rotate 180 degrees! The 2 pin are the power input and the 4 pin are for input and output signal!
Cheers.

RobotsMaking (author)KevinH2942017-02-23

I have one question about your circuit diagram: you have green circles and green circles in squares in your diagram, what is positive and wat is negative?

KevinH294 (author)RobotsMaking2017-02-23

Hi RobotsMaking.
Commonly in the diagrams the squares means the GROUND. You can see in the electrolitic capacitor you have the "-" sign with the square ones.

deepu9422 (author)2017-01-15

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

Zeeshan gohar (author)2016-12-29

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

Joe3502 (author)2016-10-22

Can I use an nte823?

patrickjane79 (author)2016-10-07

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

pruthvi-in-instructs (author)2016-03-22

can I use a 2W speaker?

Yes, you can.

Quirc (author)2016-06-30

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?

kohellus made it! (author)2016-03-30

Great instructable, works nicely and easy to make for a newbie like me. thanks alot!

vivster13 (author)2016-03-15

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

to pin 4 or 2 any ony might work

pruthvi-in-instructs (author)2016-03-22

can I use a 2W speaker?

pruthvi-in-instructs (author)2016-03-22

can I use a 2W speaker?

JGUZMANO (author)2016-03-07

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

Dulexy made it! (author)2016-02-27

Thank you.. Nice sound quality. :D

Umair.360installer (author)2015-10-07

Capacitor 220 mF 25v?

yep any volts

trax_e_rev (author)2016-01-03

Pot on the output seemed to work better for me

chris.dwyer.1238 (author)2015-03-30

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!

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

r4rony (author)2015-09-28

can i use a 4 ohm speaker ???

HighEndMe (author)r4rony2015-12-14

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

ClaytonB8 (author)2015-12-09

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

jalen01976 (author)2015-11-22

What causes too noise when i volume up. Cant even understand the music?
But it is good in very low volume. Can somebody help me? Author?
Bdw. Thanz for the diagram ?
I made it but has a little prob.

Same with me :(

nils_pan (author)2015-04-19

hi krmartin, i made it and working fine in 3 volts 4.5 volts also, thanks .....

DubMonster (author)nils_pan2015-11-28

how much watts

ClaudeG (author)2015-06-09

Can i hook up a sub to the output?

BurakC (author)ClaudeG2015-07-09

Subs need higher amps than a small 8 ohm speaker so, probably you will get lower volume.

DubMonster (author)BurakC2015-11-28

yes you can plug it, but there is not specific channel for it, and it will just play same sound as stereo, if you know what i mean

SamS60 (author)2015-09-01

wil this work if i have 2 8ohm speakers coming off of it

DubMonster (author)SamS602015-11-28

yes

VamshiR (author)2015-09-22

can we use a microphone to give our voice signal as the input to amplifier

DubMonster (author)VamshiR2015-11-28

maybe

DubMonster (author)2015-11-28

how much watts on 3v batterypack

fortney (author)2015-10-24

Hi--What is the purpose of R1? Thans

Umair.360installer (author)2015-10-07

Capacitor 220 mF how much voltage

that capacitor needs to be 16v min . 25v, 35v, are also good. Depends upon the voltage you're supplying.

VamshiR (author)2015-09-22

DonJoF (author)2015-09-08

What are the voltages of the capacitor?
Wattage of resistor? Need asap

EliB2 (author)2015-08-26

Hey cant see what your 5th pin is connected to and cant view picture in previous comments

tortiz-potter made it! (author)2015-08-18

Easy circuit to put together, idk how the potentiometer works in the circuit, when I adjust it, nothing happens.The music gets distorted after half volume.

rahilgada (author)2015-07-25

@krmartin Hi !Thanks for uploading this circuit. I tried making the same amplifier but I am facing problem the speaker doesn't give me sound. I m give giving an 12v 1Amp dc supply from adaptor,is that fine?

About This Instructable

318,339views

302favorites

License:

More by krmartin3:Portable SpeakerLM386 Audio AmplifierFull Spectrum Flashlight
Add instructable to: