LM386 Audio Amplifier

by krmartin3

334K316186

Intro: 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.

168 Comments

hkeating1122 11 months ago

The schematic drawn has an error. The right side of amplifier is pin 5. This amplifier is an odd one to me personally. My suggestion is get the data sheet from Ti and play around with it to really see how many different ways it can work. There are so many examples online and yet most of them can still be confusing, Best way to see the gain difference is by using a sine wave and an oscilloscope (if your looking for gain), If your looking for quality of any kind, go with a better amplifier. Thats my 2 cents. I would love to see a someone make one with correct schematic and data to explain what size capacitors will increase/ decrease gain and which gain outputs to use and why. And Ive also seen potentiometers placed in several different areas, Ive also seen a capacitor trimmer instead of using a potentiometer. Just to confusing for being such a basic ass amplifier that isnt even that great, at least for sound. Maybe power is the way to go with this one?

JamesJ 2 years ago

It’s not labeled but I’m pretty sure the the line coming off the tip of the triangle (lm386 ) on the circuit diagram has to be pin5 as that’s the output pin as for pin 7 it looks like there is no connection to it although It’s usually connected to earth via a 10 ohm resistor and a 0.1uF capacitor have a look at the data sheet for the amp for more info on that

Joe3502 7 years ago

Can I use an nte823?

Jimbo724 4 years ago

Hi, Joe.

Did you try using the nte823? It's supposed to be a direct replacement for the LM386. Did it work well enough?

--
Jim

deepu9422 7 years ago

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

Zeeshan gohar 7 years ago

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

patrickjane79 7 years ago

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

Quirc 7 years ago

Yes, you can.

Quirc 7 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?

vivster13 8 years ago

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

JGUZMANO 8 years ago

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

trax_e_rev 8 years ago

Pot on the output seemed to work better for me

chris.dwyer.1238 9 years ago

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!

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