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.

Comments

[Dunne111]

How could you add a led and switch and maby a USB for an iPod?

[Dunne111]

Would it work if you used 12v power supply instead of a 9v supply?

[PoLoMoTo]

Unfortunately this is a mono amp, stereo would require two LM386's

[samaddon]

I HAVE A QUESTION !
Can i use a 1000 uF capacitor instead of a 220 uF capacitor to increase bass ??

[samaddon]

I HAVE A QUESTION !
Can i use a 1000 uF capacitor instead of a 220 uF capacitor to increase bass ??

[rgupta34]

plzzzzzzzzzzz help me ........how to use those variable resistors??? and i have used 4k7 instead of 5 kilo ohm resistor ... is it ok ...
help me its not working ... i connected a jack from my guitar to input ...
its giving hisss sound only .... :(

[rgupta34]

i have used a guitar jack ,,,,, ????

[Dowaine]

if i hooked up a mic to the spot labeled in would that work

[shady24]

hey i am almost on a verge of making this ....all i need to ask is that,can i use 10k ohm potentiometer insted of a 5k ohm potentiometer

[vernkle]

that should work, but it may effect the volume and sound quality.

[nedstark]

does my speakers have to have its own power supply, i mean, i want to use the speakers for pc, which of the two do i use? will i be okay if the detachable one? thanks

[astrogotnext]

hey what electronic device carries the lm 386 chip? what other chip could i use instead and where to get it out of.......

[Insonicbloom]

Iif you want an amp with a bit more power go here I designed a quite powerful guitar amp using the TDA2030 on stripboard - there are soundsamples too it is quite simple and as per most of my designs I try to use parts I've salvaged, in this case most of the parts probably came from the same PCB as the TDA2030 - people were so impressed I had a few local players pay me to make them one.

[mrmitchell1012]

Can I make multiple amps and join them together in series or parallel them?

[nodoubtman]

5 k ohm Potentiometer not resistor
thanks! :)

[sadilrox]

IS this suitable for 100watt speakers

[djbogdy43]

I REALLY NEED YOUR HELP!
In my town I can find only LM386N..It will work?

[aplustv]

Yes you can use it! they are the same....

[tom g.]

What is the wattage of the speaker that would match this set up?

[tom g.]

Is the 10 ohms resistor 1/4w?

[rush2sk8]

can i use a potentiometer insted of a variable resistor

[nodoubtman]

its the same thing! :)

[bacha5067]

Hey can anyone give me the circuit diagram for the.... the image is not so clear..

[hrimiller]

Has anyone tried this with an ipod? i have a nano chromatic and it is really quiet with my headphones.

[JayKnight1990]

Hello everyone, I'm new to this website. I'm going to school for electronics so I will be on this site a lot. I'm also kind of a noob to everything as well so pardon me If I asked stupid questions.
I am trying to build something just like this for my class. My question is, what if I want to use a small 8 ohm 0.5 W speaker that has a red and black cable connected to it. Would I just replace the female 3.5 mm jack with this speaker?

[Ririshi]

Yes, indeed. You should connect the black to the ground and red to the signal +. I have read this chip is made to put out 0.7 Watts, so maybe you shouldn't put the amplifier on full power, or you can damage the speakers.

[bmin2709]

yes you would :)

[stupidkartik]

does anyone know what voltage capacitors to install?

[Ririshi]

I'd choose 10v or higher. Just make sure it's higher than the 9v or it'll explode =D

[Logicdustbin]

as I understand, it just needs to be larger then the supply voltage.

[D_David]

hey do i need the ic? i cant seem to fimd that ic but i found a 'TEA2025b' can that work? plz reply asap thanks

[Mark_L]

Hey do you know how i could build a amplifier for a car audio system? if you have a link to a different website or something that would be great.

[seriusbeswax]

thanks for the demo dude it works fine gonna use the design to build a more powerful one i will let u know how it went. peace

[kafi023]

hi i am kafi i want to make this amplifier i do not know anything plz help me and tag a video footage......................................

[zzmm89zz]

great job! is there any way to increase the quality? perhaps a bandwidth filter?

[rajat kosh]

I recommend you TDA IC or go to http://www.hobby-hour.com/electronics/power-audio-amplifier-ic.php for your quality amplifier

[=haineux=]

The LM386 is not an audiophile part. It also will not output a lot of power.

You need to find a different circuit. Try searching for one using a Tripath Class T chip.

[dan1023]

Hey, if you built this, what voltage capacitors did you use? Really need some help with this. Hope ur reply comes soon : )

[zzmm89zz]

Hi, you need to use the capacitors listed in this instructable, which are: 220 uF 100 uF .01 uF .047 uF Maybe these last two confused you since the author didn't include the units. All of these capacitors should be in microfarads. Also, make sure the voltage rating is at least 9V (since the battery is 9V). My capacitors were rated up to 16V and worked fine.

[ajervis]

do i have to get the 0.047? i cant seem to find it

[rajat kosh]

No its not necessary you have to only get the approximate value nearer 0.047

[ankitgarg2005]

with 12v 4.5A battery lm386 becomes 'Red Hot '.

[rajat kosh]

lm386 is a descent IC so it can only works with 6-10 v (few micro/milli amperes)
but it will give alot of noise & distortion so don't expect a high quality sound
Rather i will refer you a UPC 1288v IC according to your power supply

[Bennett9831]

How many watts of output does this provide

[Bennett9831]

I have two questions: 1 Is their a way to add a clip indicator light? 2 Can I have multiple signals coming in at the same time?

[junaid646]

frens san ny one tell abt dat 0.01mf and 0.047 wch z the positv terminal in dat..... and frens......wat abt LM386 ic pin numbr 7.... y it z left blank.... no connction itslf or wat??

[shawntherobot]

those caps don't have a polarity

[ankitgarg2005]

7th pin should be left black OK.

[ajervis]

um can i remove the 0.047? i got everything but that and i cant find it. Also how loud will this amp make 4 speakers play? with and without the 0.047

[shawntherobot]

you can remove it but the sound quality will be pretty bad

[jknig005]

what kind of speakers can i use this is my first time trying to set this up?

[Pranjal Joshi]

can i use 10 k varable resistor or 5k pot instead 5k var resistance??
wat is actual function of amplifire??
plz rply

[emersonc]

an amplifier increases the output of the speaker not by adding voltage ( that will fry your speaker without increasing sound) but increasing the input ( your ipod or other mp3 Player)

[ansarbalkhi]

Can we use OPA227 Series IC instead of LM 386 semiconductor IC?

[prarthana]

how to connect potentiometer ?

[whady]

can I use a jack 6.5 on this amplifier?

[IronWill]

Any jack should work, as they are just means of input.

[aherkendaal]

Can this type of thing power a small car speaker? its an old Sony and it'll take 25 watts, no more.

[vrejiraj]

where should i connect my speakers?

[jhutton]

im lookin at running this with an adaptor, what amount of amps will i need?

[rsantös10]

where can i put the speaker? and the volume tunner?

[ajervis]

can i use 10v capicitors?

[akumar39]

thanks buddy....................my amplifire is working ......................cool.

[asatheesh]

i'm having two 3 ohm speskers how can make amplifier for that speakers

[hiyo123098]

hay um how would i get more bass wit out the var capacitor??
cus i cnt find one...

[galmohaimen]

what is the voltage of those capacitors..?

[tevinp]

how much volts "0.01 capacitor" and how much pin "100 ohm variable resistor"?

[vpandit]

hey .............. wat if i use the source as direct elecricity instead of battery ......... will still the capacitors nd resistors remain the same ???????........... plzzz help ....

[Karlisz]

How much W does it output? I want to power 2x 2W 8ohm speakers ! Will it be ok?
Thanks!

[=haineux=]

It will drive the speakers, but won't run them at maximum power. It might be loud enough, but that's for you to decide.

[kamrul83]

what will be tha watt of the speakers?plz help

[=haineux=]

Like half a watt. The max the chip can do is about 1 watt, and at that power, it won't sound too clean.

[survivorwolf]

will a Lm393 ic work?

[=haineux=]

That is a completely different chip which cannot drive speakers. Sorry. You can google "LM393" and read the data sheets to find circuits to use that chip.

[101yummYYummy101]

I dont know what I freaking did wrong... I made it exactly as shown, but it doesnt play any sound from my ipod. Instead, if I touch the wire connecting the input to the 0.01 capacitor and that capacitor, and the 220 uf capacitor all at the same time, I can hear AM 1600 radiostation playing country music (At least it was amplified) How do i fix this?

[=haineux=]

You need to find a friend who has built circuits before, to help you figure this out.

When you touch parts of the circuit, your body is acting as an antenna and feeding the radio signal into the amplifier, where it's somehow getting converted from radio frequencies down to audio, and amplified.

Given that, it's likely you didn't ruin anything, and most of the circuit is working fine.

As a wild guess, I'm going to bet your input jack is either busted, or wired up wrong. Or the cable you're connecting the iPod to the circuit with.

[mwaris]

is this belong to class D audio amplifier??

[=haineux=]

No, actually, it's Class B.

It's basically a simple transistor amplifier circuit, designed to be flexible and require minimal external parts, shrunk into an 8 pin IC.

I think the LM386 was originally designed in the Seventies.

[hasnain101]

:@:@:@:@:@: ZABI RAuf PLzzz Tell ME Where U GEt tHIS ic (lm386) ..........................................

[=haineux=]

Radio Shack, Amazon, DigiKey, Mouser, MCM, Octopart.com

[zabi_rauf]

I got it from the electronics store in my area.

[hasnain101]

Are U pakistani


But In My Are electric store Did not Have This Ic.Can U Give ME this Ic


WHERE DO U LIVE ?

PLZ TELL ME

[zabi_rauf]

Yes i am. And im in lhr

[hasnainahmed101]

plz give me your number Or add me on facebook


[e-mail]

[Rhamkota]

I f I use a higher voltage (most likely won't work) will it be louder? also what can I do to produce high decibels? I would also, if you know this, how high of quality will the sound be (pretty much does it degrade quality)?

[sisisisi25]

Maybe 12V or something?
I wanna know too, because I wanna use it in my car.

[=haineux=]

MOST LM386 chips can run off 12V, and that would make it louder, but the maximum output will be less than 1 watt per channel, even if you drive it like crazy and it distorts a lot.

For a car, the simplest/cheapest solution is to buy a car amp box, because they are like $20.

If you want to build your own circuit, look into the TDA2005 or, if you want maximum fidelity, the Tripath chips.

[stupidkartik]

could someone help me out i really need to know what voltage capacitors i need

[TheJ0y]

you will use 9 volt battery... so 16 volt (like 100uF 16V) would be enough but you can still go higer... just dont go lower ;)

[ktalex]

these are all the materials. 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)

[thicks-1]

I am trying to get the 3.5mm male and female jack cables just like the pictures on here. Anyone know how or where I can get those cables?

[7654321]

try radioshack

[Md Wajahat]

Hi, i just went through the article and looks great, can i get a stereo ouput from the circuit ? I want to connect two speakers that should behave in stereo manner...

Please Help...

Thanks

[zabi_rauf]

This guide is for mono

[max1919]

make 2x this... each one for each speaker

[Md Wajahat]

Thanks for the updates...

lets say the output coming from ipod give three outputs like 1 2 and 3, output 1 is common for both, and the output 2 for first speaker and the output 3 for second speaker...

Just wondering, if i use pair of 1&2 and conect to this circuit and play one speaker, and create another similar circuit and connect output 1&3 to play another speaker...

Lets say the above scenario worked fine, question is whether the sound will get distributed? like i want stereo output on two different speakers as similar to my left and right ear beats change...

Thanks

[max1919]

Great instructions, thank you!
It works great with 12ohm 0.5W speaker... gain is big and sound is clear.

[ankitgarg2005]

Circuit shown works fine with high output. man u rock....

[Moonlight27]

Where does it get power? Can you make one that can be powered by an AC outlet?

[ankitgarg2005]

use AC to DC adaptor .

[zabi_rauf]

It gets the power from the 9V battery.

[Moonlight27]

Can I use it on my diy speakers?

[ankitgarg2005]

absolutely YES

[zabi_rauf]

Yes you can use it with any Speaker.

[OXI2vasyl]

help me !
i did all circuit and its works but GAIN doesnt work T_T!
my resistors are ok, i dont now what problem is happening.

[ankitgarg2005]

I also made the same circuit it worked fine for me with high GAIN. may be ur IC is damaged.

[zabi_rauf]

Maybe you have connected them wrong

[frayne999]

can i use a 9v adaptor instead of 9v battery?
Do the resistors have to be variable?

[ankitgarg2005]

u can use 9V adaptor as it is the same thing as using 9V battery. Variable resistor help in adjusting volume and tribble level.

[yonex]

can the 9v be a 5v???

[ankitgarg2005]

if u r thinking of using USB (5V) port then OK , u can use but at higher volume noice will come.

[zabi_rauf]

Nope. It has to be a 9v, you can easily get the 9V battery.

[BERO AKRAM]

what is the output power of this circuit ...... please tell me,as i make your design with some small changes and it`s good circuit but i don`t know its output power.

[ankitgarg2005]

output is quite good.

[talha91]

Oh yes in the end I found a picture through which I can continue making my Circuit the graphical diagrams sucks....

[s omer]

thank you you genies man rock on

[omerharoon]

man can you make more simple amlifiers

[abhisince1987]

its awesome and very cheap
thanks dud!!!!!!!!

[rish234]

are they 0.01 and 0.047 micro farad?

[xAxrules]

Are you sure its a 100 ohm pot and not a 100k pot?

[OXI2vasyl]

hi i confused on variable resistor part :S

[Moonlight27]

where do you connect the gnd?

[MrLeitexxx]

the negative of your 9v battery (-9V)

[Moonlight27]

How much is the estimated cost of the materials?

[zabi_rauf]

Depends from place to place. But the components are real cheap.

[SpecieS~]

Would this work with 12V, too? The data sheet of the LM 386 says the max. supply voltage is 12V, so this would be ok. But what's about the rest of the circuit?

[zabi_rauf]

I think it probably will work.

[bhoottheevil.hitesh]

i m going to try..............audio amplifier i need som clues fr audio loud amplifier.

[Jawn]

Should give this a go with my speakers I assembled from a pair of these http://www.pcloft.com/hppoaumospes.html attached to some mushroom boxes to spread the sound. Wish me luck.

[rexty]

god damn thing works :D:D;D .....took me a whole day , yet worth it

[hunter566]

i cant find a 100 ohm variable resistor what other variable resistor should i use

[KalVerd]

Could this be used for a portable stereo? ive got some big load speakers that i want hooked up to a 2 watt portable cd player. would this work?

[harleyy]

thanks alot, im going to try.

[PillsHere]

could i just use 5 1k ohms resistors?

[vaidarnav]

if i wanted to use this as a guitar amp, would it work?

i want to attach a pretty small 6 ohm speaker, 2.5 watts
how could i manipulate this amp so that it will play through my guitar to the amp and into my speakers? 

[zabi_rauf]

 Yes you can use it as guitar amp. It will as it is work with guitar.

[nidhinnair]

Hi...m going to try this project.....thanks

[drusstw]

approximately how powerful is this amp? and also can someone tell me what will happen if i supplied it with 12v instead?

thanks :)

[neuthral]

Works like a charm! :) Didn't see a difference changing the 220 capacitor thou

[Junkyardmaster14]

are 0.01microfarad and 0.047microfarad capacitors are tantalum capacitors? i put two 0.1microfarad capacitors instead of those you have on your instructable because i cant find any of those capacitors that has the same rating on your instructable. the problem is, mine wont work, can you help me?

[j03tv]

When choosing capacitors just choose one that is equal/higher than your voltage source. Which is a 9v battery in this example. In addition, usually the higher the voltage = the bigger the cap is, so consider that based on your case size.

ie.
If using 2x 9v capacitors with a 12 volt source the split between the 2 caps would be 6v each. However, if something fails and the capacitors arent balanced, one cap could get all 12v and damage it.

[un0]

Is R1 control the amount of power going to the speaker (volume control)? and can you place a 10K potentiometer (variable resistor) between the capacitor and pin 8/1 for controllable gain?

[MilotisX]

i believe it is

[meshrammanish]

one more question... well i got a HWCAT CSC386P... will it work???

[meshrammanish]

tell me dude... the 220 micro farad and 100 micro farad capacitors are required for what voltage??? i made the same circuit but it doesnt work. i've added both the capacitors of 40 volts.

[Calumon]

hey do you know how many decibels this thing puts out?

[zabi_rauf]

Sorry. I dont have any idea that how many decibels it puts out.

[Calumon]

You should sell that on ebay, cos i cant find the things to make it and im try to make it for science fair.... =D

[zabi_rauf]

Wish i could help you. But i am in a country where there is no ebay.

[Calumon]

ah its ok =P
im found some things at radioshack
but i couldnt get a project board, would a pc board work?

[zoltzerino]

Yes, A PCB would make the project 'final' as it were, a project board (or breadboard) is for prototyping (testing) circuits before you produce them on a PCB. Because you are working from a pre made circuit diagram (schematic) you shouldnt have to test it.

[sani]

i have made this amplifier... it amplifies about 50 times i have checked it on a oscilicope in ma university... the only proble i get is distortion of sound... but when i plug it to my mobile there was no distortion but it do heppen in pc.. well m very thankful to the creator of this project.. i have tried 2200 uf capacitor in bass instead of 220uf... it has biven a boooooooost to bass... wel i hav also added a LED in parallel to 220 uf capacitor; +ve leg of led to +ve leg of capacitor and negtive to -ve... now it gives the phinemona of charging and dis charging of capacitor means it glow with the beat........ and dat looks so awasome.... then i put lot of leds and some more capacitor it was relly awasum xperience... and dnt 4get to put a resistor on the +ve leg of led.... apply the formula V=IR.... v is 9-12 the vlotage ur giving to the circuit.. impidiece of led is 0.03 and u get ur resistor to add

[zabi_rauf]

Great to hear that you have made it and improved the design .

[Derin]

cat5!

[carik]

ok i am really confused... have you just made up your own symbols, have you ever seen a circuit diagram before? dont get me wrong this is a great guide but it would be a lot more helpful if all the symbols were actually real symbals

[cld0000]

http://i731.photobucket.com/albums/ww311/xcldx/schematic.jpg
I redrew the schematic, and replaced the original schematic symbols to the proper ones(except input and output, for I don't know what they were).

[Gasburner]

They aren't circuit symbols, they are what the components look like, arranged in such a way so that we can see how they are connected. It is meant to look like how it would on a Printed Circuit Board :)

[tinman123]

how do you change the volume on this amp?

[cld0000]

the variable resistor knob next to the output. the other one adjusts the gain(how much is being ampified, in a sense).

[freerunnin1]

try adding a variable resister to the circuit ( i dont think that it matters where but try putting it somewhere along the battery input wire) :)

[Gasburner]

Put it on the output wire :] battery input wire will just screw up the chip

[octopusowen]

Hello, The 0.01 capacitor & 0.047 capacitors are they audio capacitors or are the like in farads or micro Farads ?

[cld0000]

By default, they'd be in microfarads. if it was in farads, it'd be deadly if someone accidentally touched it, and probably require more power to operate it.

[tonjel2]

hellow

[mayney93]

where can i get those parts in the uk and how much louder will it make the mp3 player?

[octopusowen]

Maplin go to http://www.maplin.co.uk to find stores

[jlei]

Hey bro, i would like to try your work. But i would like connect the ckt to a 220 volt power supply instead of a 9V battery. What else do i need? Wt type of transformer, (its rating)? And ofc0urse a rectifier. Can you please help me do that. Thank u! Hope to receive ur reply soon.

[irvinaby]

it works perfectly, thank you.

[neumanngregor]

You shod read the National Semiconductor daasheet for the 386 (google "LM386 datasheet") and there read at page 5 the "Typical Applications" there u get a better drawed schematic and if you got "bad sound" u can replace some of the values from here with the values from the datasheet ... It is a nice ideea and it use common components (lm386 is under 1euro available) ...

[james25]

how many watts is this kind of amplifier?

[joinaqd]

how loud would you say this thing is?is it louder than directly connecting an iPod to a speaker?

[zabi_rauf]

Yep it is louder than directly connecting the ipod to the speaker because it amplifies the sound.

[Kalasburken]

Hey, on the variable resistors, how do I know which pin is which? /beginner

[tinman123]

thanks :)

[vedran]

Great project!!! I did make this and it works for mp3 player, guitar, computer and everything. But I have a problem. Output is very low and distorsion of sound is high(this is my problem). I have tryed to regulate input by variable resistors but nothing worked. If someone have idea....?

[Xellers]

This is very similar to the ruby amplifier, and if you saw the video on that one, you probably heard the terrible distortion. That is the only reason why I don't build one....

[kalamaku]

Hoe I know thoes values? 2- 100 micro Farad capacitor V? 3- 220 micro Farad capacitor V? 4- 10 ohm resistor W? 5- 5 kilo ohm variable resistor W? 6- 100 ohm variable resistor W? 7- 0.01 capacitor V? 8- 0.047 capacitor V?

[ballooneater]

Because this is a low-voltage application, capacitors should be over 16v (going higher doesn't matter) and resistors should be at 1/4 Watts.

[camellia]

i would like to inquire regarding the capasitor values listed 1) 0.01 capasitor 2) 0.047 capasitor what exactly are the values for these capasitors?? are they understood simply as Farad or probably microFarad?

[ballooneater]

Capacitors are almost always in microfarads (uf) of picofarads (pf). If no marking is given, uf is assumed.

[Wareagle]

how much does all of these components cost?

[thefutureisnow]

Will this circuit work on a voltage rage of 1.5v - 3.7v?

[killersquirel11]

This is a step where the yellow box things you can do would really come in handy. (hint..hint..)

[AceFace]

Could you just put two potentiometers in place of the variable resistors? Or would that blow it?

[AceFace]

also, is the 9v Plus supposed to run through the pin 6 and then to the capacitor? or around pin 6, but you didn't have the room? I just can't tell but I might go with my first instinct.

[zabi_rauf]

I am not sure exactly because i have never used variable pot resistor,but i think that the middle one will be C and the A,B will be the side ones ,doesnt matter which side.

[detrimental_dude]

im using the variable resistance (pot) with the knobs how do i find A, B, C. Im getting a very faint sound frm the amp

[pad]

Is it possible to use two blocs of this amp together?

[aaronX987]

Made it and it works great. Better than I expected. PS If you do not want to make another one for stereo connect the left out and the right out together. :)

[zabi_rauf]

I think you probably can.Because its an amplifier and will amplify the sound from crystal radio.

[nickbuls]

can I use it for making the output of a crystal radio louder so I can attach a normal speaker to it.

[tech-king]

nice. i could attach this directly to my subwoofer.

[Ohm]

I doubt the lm386 would have enough output to effectively drive a sub and it would need a lowpass filter in front to get the right frequencies to the speaker.

[tech-king]

actually, i was thinking of amplifiing the signal going to the sub, not actually driving the speaker off it.

[GorillazMiko]

Smart idea, way too hard for me, but just looks awesome, and very nicely done. Great (VERY great) job!

[Brennn10]

You should fine a wooden box to put this all in, put the jacks on the outside, and you can take it wherever you go! Nice!

[The magical duct tape kid]

Cool!