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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.
 
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Step 1: Obtain Parts

Picture of Obtain Parts
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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

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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
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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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rahilgada9 days ago
@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?
NoahH516 days ago

just a question not necessarily related to the topic, but if I needed to solder a left input, ground, and right input, what wire colors correspond to each if I have a black, red, and then the ground wire.?

ClaudeG1 month ago
Can i hook up a sub to the output?
BurakC ClaudeG25 days ago

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

gsilviu1 month ago

Can I use it on a 16 ohm speaker?

BurakC gsilviu25 days ago

Yes, you can use 16 ohm but it will provide you 2 times less volume then 8 ohm.

SreehariM made it!2 months ago

There is one mistake in the above circuit diagram.

Pin 5 is missed out and that is causing a lot of noise problem.

Here is the corrected figure.

-Sree

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I cant open the pic where is pin 5 connected to?
ClaudeG2 months ago
What should i do about pin 5 of the lm386 im hearing littke noise
SreehariM ClaudeG2 months ago

Yes that is causing all the noise problems.

I have uploaded the corrected circuit including the connection to pin 5.

-Sree

SreehariM2 months ago
JohnB711 months ago

Where is a good place to buy capacitors and resistors, every time I google the specs of a capacitor or resistor they all look way different

tclayton JohnB72 months ago
Look up "joe knows electronics" on amazon. He sells kits that have all standRd sizes of caps all labelled and organized in bags , saves all the shopping around
tclayton JohnB72 months ago
Look up "joe knows electronics" on amazon. He sells kits that have all standRd sizes of caps all labelled and organized in bags , saves all the shopping around
mgrandi2 made it!2 months ago

That's the best configuration I've worked out. It sounds nice!!

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mbenavides1 year ago
Just wondering but i got a lot of distortion with this amp, how did you clean it up?

Tantalum cap (10 - 22 uF) across the power rails. Watch polarity on the cap.

sladejas3 months ago

I built this and it works much better than the default version on the TI datasheet. If you are experiencing distortion on the output (either audible or noise on the O-scope), add decoupling caps to the power rails. A 10 - 22 uF tantalum cap from power to gnd (watch polarity of the cap) cleans up the signal very well . Try it if you are getting noise!

nils_pan3 months ago

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

nils_pan3 months ago

hi krmartin, i made this but unfortunately not working, i haven't used R3 Potentiometer 10K Ohm bcoz due to sortage not available locally, can i skip it or use 10 var...

diygeek0073 months ago

pretty simple circuit.good instructable. thank you :)

asimobot4 months ago
Hey, im bout to build this and im new to this kind of thing. when u connect the power output how do u connect both negative and positive to one wire

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!

hi I was wondering if this would work with 2 speakers for left and right or just the one speaker????? If it would work for 2 speakers does anything change or everything stay the same????? would really like the help.

You can do with single output. Take single output and attach to stereo jacket.

For audio wire

Left side - circuit: signal-signal twisted together and ground

Right side- jacket: signal to left pin, signal to right pin jacket and ground to ground pin of jacket

You need audio wire and stereo jacket, ask to electronics vendor what is the ground pin of the 3 the other 2 are indifferent signals

Build 2 circuits and input L & R to individual circuits each having their own speaker.

pbardolet1 year ago

I've built the amp, and the music can be heard through the speaker, but in a very low volume, like if it's not being amplificated. Can anyone help me with that? I don't know what's happening.

Thanks.

Adjust you input potentiometer.

vinu mystify10 months ago

where is the pot in the circuit?

its R3, but i dont think it is in his build

16401012417 months ago
ricardov18 months ago

Cool, it really works, but i have a doubt about the components and about calculating scaling, Could you help me?

apuzari8 months ago
Worked like a charm!!!
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shekzz.rock9 months ago
Can I connect 2 8 ohms 3 watts speaker to dis amp..?
erik4049 months ago

Is it possible to swap the speaker for a mono jack output and connect the circuit to a mixing desk or even a audio input on a soundcard?

gpfanatic erik4049 months ago

I think so. Important Rout of this circuit is low how should to be and Rin audio card is high as usual

gpfanatic9 months ago

In this project is lacking output impedence versus speaker inductive component. In parallel to speaker is needed a RC circuit to balance inductive component of speaker. If you need to understand more on audio amplifier ask for my electronics website in PM

ktomar11 year ago
Which volts capasitors used in this.. ?
gpfanatic ktomar19 months ago

16 V works fine

Any capacitors with larger volts that power source voltage.

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