Make a Simple Audio Amplifier




Posted in TechnologyAudio

Introduction: Make a Simple Audio Amplifier

It is my first instructable.Lets see how to make an audio amplifier which you can use with any of your musical instruments like guitar,piano and with ipod and other devices.So Lets begin the journey....

Disclaimer: If following this guide anything damages i shall not be held responsible.Do it at your own risk.

Step 1: Components

You need the following components

1- LM 386 semiconductor (IC)
2- 100 micro Farad capacitor
3- 220 micro Farad capacitor
4- 10 ohm resistor
5- 5 kilo ohm variable resistor
6- 100 ohm variable resistor
7- 0.01 capacitor
8- 0.047 capacitor
9- Wires
10- 9V Battery clip
11- 9V Battery
12- 3.5mm stereo jack male
13- 3.5mm stereo jack female
14- Project board (or you can use dotted board and solder)

You can find these electrical components from your nearest electronics store.These all components are easy to find and are common so you won`t have a hard time to find it.

Step 2: Circuit Diagram

The circuit which we are going to make is.

Thanks to cld000 for schematic drawing.

Step 3: Placing the IC

1- Place the LM 386 in the project board as show in the image.

2-If you pick the IC in front of you (so you can read what is written on it) then the lower left pin is 1 and the pin number increase anticlockwise.Take a wire and join the 3rd pin to 4th pin(GND pin).

Step 4: 0.0.1 Capacitor

Join the one pin of 0.01 capacitor with the 2nd pin of IC. The other pin of the capacitor should be joined with the INPUT.

Step 5: GAIN Controller

4-Now join the 1st pin of IC with the A pin of the 5 k ohm variable resistor.
Join th A pin of this variable resistor with the C pin.Lastly join the 8th pin of IC with the B of this variable resistor.This becomes the GAIN.

Step 6: 100 Micro Farad Capacitor

5-Join the +ve side of the 100 micro Farad capacitor with 6th pin of the IC.The -ve of this capacitor should be joined with GND pin (4th pin of IC).

Step 7: 10 Ohm Resistor & 0.047 Capacitor

6-Join the 5th pin of IC with one side of 10 ohm resistor, the other side of the resistor should be joined with the one pin of 0.047 capacitor. The second pin of the capacitor should be joined with the GND pin (4th pin of IC).

Step 8: Volume Controller

7-Now again join the 5th pin of the IC with the +ve side of 220 micro farad, the -ve side of the pin should be attached with the A of the 100 ohm variable resistor.The B pin of the variable resistor should be connected to the GND pin (4th pin of IC).This becomes the Volume controller.

Step 9: Input and Output

8-Join the +ve pin of the 3.5mm stereo jack female with the C of the 100 ohm variable resistor.And the GND of the female jack should be attached with the GND of the IC (4th pin of IC).

9-Join the +ve of the 3.5 mm stereo jack male with the other side of the 0.01 capacitor and join the GND of the male jack with the GND of the IC.

Step 10: Testing

10- Last but not the least join the +Ve of 9V battery with the 6th pin of IC and -Ve of the battery with the 4th pin of IC.

Congratulation !!! you have made your own simple audio amplifier.

Now the time to check it out.Join the male jack with your mp3 player or musical instrument and female with the speakers.Now adjust the Volume and Gain to get the best and loudest possible sound.I should notify you that with this amplifier only one speaker will work.And do the adjustment from low to high.Do the adjustment carefully or it can damage your speakers.

You can change the input jacks as your requirement.You can add a 220 micro farad variable capacitor instead of simple 220 micro farad capacitor to change the bass.

ENJOY !!!!

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how to know + - input? i make 100w amplifier.. n my speakers is not have sound.. just ear a bippp only.. can help me?

Hello. I made speaker box for my laptop and added two speakers. 25 watt and 3 watt . Sound is low. It needs amp? Can you help me?

I used 2 LM386 chips and did mine on a pcb. At first the sound was soft and easily distorted. I then went to check out the data sheet for LM386 and realized this chip could take 18v max. So I dug around my box of old power bricks and settled for a 14v 3A one and I must say it sounds a million times better!!

5 replies

Can u give me ur circuit design bro?

can you send the part list of the amplifier you made??
i was a student and i want to try how to make a amplifier??

hey dude does it work on an empty PCB like this ? because i don't know how to make printed one

Hey... I like your design... I have 2 speakers 6 ohms each... can you explain your components and your design in detail to me..? I want to make it at home.

Thank you in advance.

Haha what i did here is exactly the same as the instructions mentioned above. The only thing i did different was that i did mine on a PCB and added a few extra components which were then 2 connectors for the speakers, a female stereo 3.5mm audio jack and another connector for power. Since the Lm386 is a mono amp, i used 2 for stereo. I just did the same circuit twice on one PCB and shared the power between the two. The audio input for both circuits is combined into one female stereo 3.5mm audio jack for easy usage. I also bridged alot of connections using the snippings from the components (i try not to use wires) which makes for a nicer looking finished product. Thats pretty much it. Happy building!!

please can I use anything equivalent to the lm IC?is hard getting one here. and also I need pictures of the capacitors showing clearly their writing so that I know them when I go for it.please send it to me on db on KWABENA REUBEN (ZENITH) .search it on fb please I need your help.

I need to make an amplifier for two 4 ohm 3 watt speakers to play audio from my phone.So what are the changes required

Thanks I made using LM386 and remove the distorted noise using mini transformer

I went to an electronic shop and asked for the 5 kilo ohm variable resistor and 100 ohm variable resistor. I got somethings like this (Look at the images attached). Is it really the component needed for this project? Can I make this amplifier using that? Please. Someone help me out.

P_20170118_191005 (FILEminimizer).jpgP_20170118_191052 (FILEminimizer).jpg
4 replies

Yes those will work. The one on the right looks like it's a 22K though, it says it on the bottom of the metal can.

is 22K a problem? Can someone tell how to use this?

It is best to use the 5K Ohm variable resistor. The 22K Ohm would work but is going to change the gain from the IC. Could be good; could be bad.

Can you help on below question
i have make an amplifier for below speakers, which components are required for this?

i have Total 5 speakers

two speaker(8 ohms 30 W) ,two speaker(4 ohms 3 W) & one speaker(15 ohms 3 W)

I have also made but it's not working, please help me.

1 reply

I know this was 3 years ago and you've probably figured it out by now, but it looks like your ground (black negative terminal from 9V battery) isn't connected to anything.

does anyone know if this will work for a 3.4 ohm car speaker