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

Pot on the output seemed to work better for me
<p>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!</p>
<p>green is left red is Right black is grond.</p><p>Connect green and red to the input pin and black to ground and that should work</p>
<p>can i use a 4 ohm speaker ??? </p>
<p>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</p>
<p>I actually have an application for the noise. Please tell me how to use pin 5 to aggravate the noise. </p>
What causes too noise when i volume up. Cant even understand the music?<br>But it is good in very low volume. Can somebody help me? Author?<br>Bdw. Thanz for the diagram ?<br>I made it but has a little prob.
<p>Same with me :(</p>
<p>hi krmartin, i made it and working fine in 3 volts 4.5 volts also, thanks .....</p>
<p>how much watts</p>
Can i hook up a sub to the output?
<p>Subs need higher amps than a small 8 ohm speaker so, probably you will get lower volume.</p>
<p>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</p>
<p>wil this work if i have 2 8ohm speakers coming off of it</p>
<p>can we use a microphone to give our voice signal as the input to amplifier</p>
<p>how much watts on 3v batterypack</p>
<p>Hi--What is the purpose of R1? Thans</p>
<p>Capacitor 220 mF how much voltage </p>
<p>that capacitor needs to be 16v min . 25v, 35v, are also good. Depends upon the voltage you're supplying.</p>
<p>Capacitor 220 mF 25v?</p>
What are the voltages of the capacitor?<br>Wattage of resistor? Need asap
Hey cant see what your 5th pin is connected to and cant view picture in previous comments
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.
@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?
<p>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.?</p>
<p>Can I use it on a 16 ohm speaker?</p>
<p>Yes, you can use 16 ohm but it will provide you 2 times less volume then 8 ohm.</p>
<p>There is one mistake in the above circuit diagram.</p><p>Pin 5 is missed out and that is causing a lot of noise problem.</p><p>Here is the corrected figure.</p><p>-Sree</p>
I cant open the pic where is pin 5 connected to?
What should i do about pin 5 of the lm386 im hearing littke noise
<p>Yes that is causing all the noise problems.</p><p>I have uploaded the corrected circuit including the connection to pin 5.</p><p>-Sree</p>
<p>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</p>
Look up &quot;joe knows electronics&quot; on amazon. He sells kits that have all standRd sizes of caps all labelled and organized in bags , saves all the shopping around
Look up &quot;joe knows electronics&quot; on amazon. He sells kits that have all standRd sizes of caps all labelled and organized in bags , saves all the shopping around
<p>That's the best configuration I've worked out. It sounds nice!! </p>
Just wondering but i got a lot of distortion with this amp, how did you clean it up?
<p>Tantalum cap (10 - 22 uF) across the power rails. Watch polarity on the cap. </p>
<p>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!</p>
<p>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...</p>
<p>pretty simple circuit.good instructable. thank you :)</p>
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 <br>
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.
<p>You can do with single output. Take single output and attach to stereo jacket. </p><p>For audio wire</p><p>Left side - circuit: signal-signal twisted together and ground</p><p>Right side- jacket: signal to left pin, signal to right pin jacket and ground to ground pin of jacket</p><p>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</p>
<p>Build 2 circuits and input L &amp; R to individual circuits each having their own speaker.</p>
<p>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.</p><p>Thanks.</p>
<p>Adjust you input potentiometer.</p>

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