Simple Stereo Amplifier

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Introduction: Simple Stereo Amplifier

Though it may not look like it, the circuit in this instructable is so easy anyone with even incredibly basic electronic skills can do this.  The circuit shown below is actually 2 mono amplifiers (mono is single channel, for those who don't know).  You don't even need to know how to solder and almost all the parts can be purchased at the nearest Radioshack. 


P.S.  The camera that I am using is old and close-up pictures are blurry.  Also the microphone on the camera sucks so the circuit will appear to be horrible-sounding, but it actually sounds good when you play it in your room or wherever.

Step 1: Gather Parts

What you'll need:

2-  LM386 audio amplifier IC
2-  220uf of greater capacitors
2-  0.1uf polyester capacitors
6-  jumper wires
1-  1/8" stereo headset jack
2-  speakers
1-  9 to15 volt battery
1-  connector for battery
1-  breadboard

Step 2: The Diagram and Pre-Build Info

This is the schematics for one of the channels.  Build two of these.  On your jack you will need to know which are your signal wires and which are your grounds.  On the next step I will try to show you where to make your connections (how to breadboard the circuit).

Step 3: Build!

Assemble.  Use the pictures as i put the notes on them:

1) Put the chips in.
2) Put in the polyester caps as shown.
3) Plug in the jumpers from pin 2 to pin 4 on each chip.
4) Attach jumpers from pin 6 to the positive side of your power supply.
5) Attach the 220uf caps as shown.
6) Connect the headset jack connections.
7) Top view of previous picture.
8) Hook up a jumper from pin 4 to the negative side of your power supply on each chip.
9)Add your battery connector observing polarity.
10) Connect your speakers.
11) Add battery and double check connections
12) Yay! You're done.

Step 4: Have Fun

Here is a video of the circuit in action.  Like i said in the beginning of this instrctables, the mic on my camera sucks so the sound quality of the video will be horrible as well, but in real life the sound quality of this circuit is pretty good.

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    79 Comments

    This is sooo simple to build and it sounds good

    i've built half of it (only had one IC) but when i use it the IC heats up. Where should I add the resistors? Thanks for thegreat instructable

    For people asking about volume control, I added a 10k pot from pin 8 to a 10µf cap to pin 1. With the pot I have one in the middle and one on the outside. It seems the range is small after I go pass the mid point of the pot, could be the pot or whatever but that's what worked for me.

    7 is left alone, if you put a 10µf cap between 8 and 1, + on the 1 pin side, it will boost gain.

    i don't understand why in the diagram there is only 1 input shown ?? what about the other

    and the value of ceramic is .01uf

    how about if ceramic capacitor I use

    ?

    is it Okey

    can i power it buy laptop usb connection

    how will we supply volt to both ic's????should we join both the ground and positive wire with each other from both the ic's and then supply it with 12v???????????

    1 reply

    Exactly. Also, depending on what you use as a power supply, you may need to filter the supply rails. If you're using a battery or a regulated power supply though, don't worry about it.

    What Class of amplifier is this? Please respond. Thank you :)

    im salvaging a samsung speaker system. left and right channel has 2x8 ohms speakers and a tweeter. the center channel has 2x4 ohms in parallel. i want to know how to integrate that to an existing stereo amp from an ihome cube speaker. is there any way to make it work? i have solderless breadboard and thinking of copying the parts layout there to test fit all components.

    If I wanted to add several speakers or use bigger speakers, what modifications would I have to make? Is it just as simple as adding speakers symmetrically to each amp and upping the battery power while making sure that the components can still handle the voltage?

    I want to add a volume control to this circuit. What should I do? Thanks in advance...

    1 reply

    If I'm correct all you need is to wire a potentiometer to the circuit. All volume controllers are potentiometers that control how much power can go through it.

    The capacitors filter out DC signals from the output, so in a way, yea.

    great instructable, wat is the output in watts and can i use the small 8ohm speakers

    what ohm are the speakers