LM386 Audio Amplifier

[SajjadBro]

where do u get these background musics...i love them :)

[TheOffPowerZero]

yeah put in the soup tonight at supper love it!!

[Cristi0986]

heloo these amplifier i can use to a geiger counter?PS,srry for my englesh

[kolokoy389]

that is a singel channel audio amplifier inside of box.. MP3 player is a 2 channel audio output (STEREO) you mean mix a 2 channel output your MP3 Player?

[cerbat]

May I know the title of the music?

[kane100574]

Mines pretty noisy :(

Any ideas to check/get rid of so much noise? Every thing seems secure connections wise...

[HackaweekTV]

@kane100574 Try reducing the signal level at the input.

[andersonblum]

Very good, but I have a doubt. where is the input of the circuit? if possible, post the schematic to the change, ok?

[186kms]

You made no mention of the types of caps you are using, electrolytic or ceramic. Is the 100uF cap at the input from + to ground, electrolytic? The one for gain, what kind is that, no polarity mentioned on either. You did put + and - sign on the 220uF cap but none of the rest….

[militaryson94]

Just learned to read schematics. I didnt see how you added in the 1.5mm Jack for the guitar. Can you post a schematic or show how you added that in? Thank you for this video, Really neat. Now just to make some stomp-boxes out of it xD

[HackaweekTV]

@militaryson94 You just connect the positive output signal to the part of the jack that goes to the tip of the plug, and connect the ground of the circuit to the other terminal near the ground ring on the jack.

[militaryson94]

@HackaweekTV

So its just a standard headphone jack and a 1.5mm jack connected on the same output?

[Youcansuckme69]

What exactly is the purpose of a 'decoupling capacitor'?

[HackaweekTV]

@Youcansuckme69

From the Wikipedia post:

"A decoupling capacitor is a capacitor used to decouple one part of an electrical network (circuit) from another. Noise caused by other circuit elements is shunted through the capacitor, reducing the effect they have on the rest of the circuit."

[deebsboy]

" 'But why don't you just make 10 the loudest?'...'These go to 11.' "

[elektrodenio]

How are you using a bass guitar without a preamp.

[mrfuzzles92]

I totally tried this and it works fine, not the best quality but... thats probably my fault. Interesting thing is when not connected to an input it picks up AM radio... haven't figured that out yet.

[slayer2011bs]

iron man! :D

[techguytyler]

lm386s are good and all but see me build a amplifier from a lm317 regulator

[Exelbaradin]

i wish there was a more noob friendly diy

[HackaweekTV]

@Exelbaradin

Build a few easier projects first, then come back to this one. :)

[david99soad]

is the 10K potentiometer logarithmic or linear?

[HackaweekTV]

@david99soad

Preferably a logarithmic pot.

[DJ027X]

Best electronics vid I've seen; you explain everything very well. I built a similar circuit and actually housed the chip and speaker right inside of a guitar for a self contained portable amp.

[4lifeNerdfighter]

I hope you still read these comments.

Would you have to put in the pot? I'd like to have mine be fixed volume and jsut vary the input volume to change it. Could I just have the signal go into a capacitor, then pin 3, without a resistor? Thanks dino!

[HackaweekTV]

@4lifeNerdfighter You don't need a resistor. You can just eliminate the pot and go directly to the capacitor connected to pin 3.

[box303]

I man, thanks a lot for your video! I tryied to built it but it doesn't work! Likely I make some mistakes! I also try this with the original schematics found in the datasheet of the lm386 (and again, it doesn't work!) About that, I have a question (maybe a stupid one!). In the datasheet, there is exactly your schematics, but, the componets in series at pin 5, (the 0.05 Capacitor and the 10ohm resistor) are in the opposite position... can you tell my why?

[riothero313]

nice project, the spec sheet shows the amp can put out closer to a watt if the input voltage is 18v. seems like just adding another 9v in series should do the trick.

[HackaweekTV]

@riothero313 Yes it should. You may have to heat sink the chip though.

[sony77206]

how we can learn any thing he went to fast ,dint said the name of any conponents @the practical i am yest a kid i learn by obcerving do is a great idea buen nerdo.

[karamelizesogan]

Today I built my circuit on a breadboard, played some songs and played my bass through it :)

Works perfect! Thanks a lot! Tomorrow I'm going to solder it on pertinax, hope that works out well, too.

[sadllebronc]

can you help make one with 48v ?? thanks.

[paintballingguy]

Does it have no sustain or is that just your shotty playing?

Everyone I've ever build sounds better than that.

[MrKamikazeTV]

i forgot it, what is Vin on the schematic?

is it the audio input - , and voltage input + is audio + ?

[jrocco36]

These are great little amps. I made so many of these I can make them in my sleep. I used to harvest these from old computer modems since they used them to make that handshake sound.

[meade9166]

you-ve done this like Kip Kay

[greenhomepro]

Very cool Amp. Could I get the complete schematics that includes the Volume, switch, LED and the two types of inputs and outputs? I just want to find out where I would have to put those items and all in the circuit. Very cool Mini amp. Im excited to build it. Thanks again!

[madamerotten]

I noticed that your waveform has a high-frequency parasitic oscillation at the negative peaks, which may indicate that your Zobel network has to be adjusted in value (the 10 ohm resistor and/or 0.047uF capacitor). You attribute the loud output waveform to the output capacitor, but some of the effect is also due to the fact that you've saturated the amplifier. The 0.01uF, 0.047uF and 220uF capacitors are not used for decoupling as you stated. Regardless, I really liked your video very much!

[GHOSTTOYS]

11 is one louder loll ... where would you go other wise ...

[last1standing96]

wait is that pico or nano farad i cant see xD

[PhuckHue2]

there are a lot of chips that are better than the LM386, especially the ones from LT

[bensonak47]

are you using linear or logarithmic pots?

[MusicaUrbanaLatina]

A CAT 05:45 #LOL

[Amphibianman94]

I've been wanting to build this and I'm stuck as far as the connectors go. I want to be able to plug in my iPod, for which I'll need a 3.5mm TRS as an input connector. However I have no idea how to wire it. Can you point me to a guide of some sort that might be able to help me out?

[Amphibianman94]

@Amphibianman94 TS* connector. forgot it was mono.

[Matthington10]

To make it stereo could i just make 2? and then have 1 for left and 1 for right?

[HackaweekTV]

@Matthington10 You certainly could do that.

[Matthington10]

@HackaweekTV  Thanks for the video and promt rely! ;D

[MrFunyman1234]

@Matthington10 lol did >:D except i put 5 on each side and had to add extro volts >:D

[Matthington10]

@MrFunyman1234 Hahahaha sick! 5.1 surround sound :P haha

[MrFunyman1234]

@Matthington10 yup and i paid 5.89 CASH FOR FRIGGEN 10 8OHM SPEAKERS THEY RULE LOL i love radioshack

[1787dude]

nice oscilliscope

[MrKamikazeTV]

hei, i'd like to build one, i already have got the lm386 and 0.5w 8ohm speaker.

but one thing what i dont understand is, where do u get the other wire to input? theres Vin on the schematic it is + or - to input? and wheres the other one?

and those triangle things shaped like this down here, these are all negative(-), and i connect all of them from the battery - to output(speaker) - ? ------ ---- --

[HackaweekTV]

@MrKamikazeTV

The negative signal input is to ground, as is the negative output. Yes, it's that symbol that looks like a triangle pointing down made up of horizontal lines.

[MrKamikazeTV]

@HackaweekTV but how many Voltages have the capacitors to be?

i right now have 10uf 16v capacitors, does it work or does it have to be under 9v or more than 9v ?

[HackaweekTV]

@MrKamikazeTV

In ant circuit, capacitors should be MORE than the voltage that the circuit operates at.

[dookiebabii]

looks like 1 person doesn't appreciate electronics

[grimsdagger]

I SUBSCRIBED!! This is awesome. I really like the music for this video when you build the circuit on the permanent board, what was that song?

[malchev2003]

Can you build a Amp for metal detector?

[HackaweekTV]

@malchev2003 A metal detector project is in the works...

[itspennysboat]

RTFM! haha

[davidryan05]

can i incorporate an LDR in this circuit in a way that it will turn on when the LDR detects light and turns off at dark?.

[zrczrcz]

that i'm right. I know the capacitor symbol is two lines (curved one is positive), and it was hooked up according to your schematic. Please get back to me on this, I spent 36 cents short of 40 dollars to buy all the materials.

[zrczrcz]

@nkmundle Thank you. I used the website and it worked.

[HackaweekTV]

@zrczrcz My mistake for not labeling that cap! The positive side goes to pin #1.

[zrczrcz]

@HackaweekTV also, you mixed up the voltage in and the music in. I'm just trying to help other people. I started to solder to the pcb today, but this is my first time. i got solder all over, but i m sucking it up with a desoldering bulb. im going to keep working on it tomorrow. THANK YOU FOR THIS VIDEO!!! It made me think! (Well, I do that anyway). Also, i just realized that the curve on the capactior is negative.

[zrczrcz]

Is it connected to the potentiometer? Also, does polarity matter in the capacitor connected to the gains (Pins 1 and 8)? I used exactly the parts that you said. Maybe there are faulty pieces on the breadboard? I'm going to place it on the circuit board tomorrow and see if maybe there were faulty connections. I am sure that the battery is full, my meter said 9v's, and it burnt out 2 led's (teehee). Please help me with this. I figured out how to read a schematic without any help, and i know (ctd

[zrczrcz]

Hey @hackaweektv ! I just wanted to say thank you for making this video about the audio amp and I'm a big fan. I'm 13 and I just bought most of the parts yesterday and I'm very excited to start. Also, can you make a video about how to make a simple transistor amp (if you know how)? That would be greatly appreciated. I hope that you do more than 52 hacks because I enjoy them so much.

[liveatthej]

Thanks man. I built it and added a gain switch; one is one gain, two is 360ohm, three is straight 10uf. I used a 100k pot as well. Built a wood box and have a mini bedroom jam amp. :)

[coondogtheman1234]

How long did it take you to build one of these? I've seen many vids on here of people building these and i'd like to make one,. BTW I have thos toy voice changer megaphone and ituses the LM386 amp. I've modded it to take a line input from an mp3 player as well as an external mic and I put a speaker output and added an on off switch and LED so I know it's on. I have a vid of it on here look up Modified toy voice changer megaphone and it's the red one.

[checkmate110]

You can lose the switch by using a TRS plug for the input jack and wiring the - side of the battery snap to the ring connector and tne board ground to the sleeve connector. Putting a mono plug in the jack will connect the ring to the sleeve thereby completing the ground circuit between the battery - and the board.

[xspert1970]

I have been harvesting parts from old electronics I have many chips that I know are from amp circuits from tv's and vcrs. is there a way to cross reference the numbers to see how the chips are configured...also I dig all your videos

[w1jsb]

Please tell me, does this generate much heat? I recently built this 1 watt audio amp: Rainbow Kits Audio Amplifier AP-1W. Maybe it uses the same chip, but I know the thing heats up very fast, even at mid volume, so I'd like to build something more efficient... Any help is appreciated, thank you.

[HackaweekTV]

@w1jsb I've had no heat problems with the LM386. If it does, you could just put a a heat sink on it. Use some heat sink compound between the chip and the heat sink. I doubt if you'll need one though.

[LauxHawk]

@w1jsb Should make VERY little heat unless you are using a low impedance driver, like a 4ohm.

[TunioMir]

@w1jsb sometimes chips are meant to get hot, you should check the datasheet for normal operating temperatures and compare them with the temperature of your chip! hope this helps

[LauxHawk]

Just built this. For most applications like iPod, I think leaving the gain at 20, (no 10uF capacitor or resistor from pins 1 to 8, will give you the best sound quality, and it will prevent from too much distortion. A gain of 200, like in this video might be good for making some sort of bass/guitar amp because it will give it that overdrive/distorted sound. Also, if you are running it with a 9V battery like most people choose a driver with the highest SPL you can find = Louder/Longer Battery Life

[Ibringthetruth1]

Capacitors are used to store electricity.

What would this sounds like without caps?

[LauxHawk]

LOL. "It goes to 11" <3

[HackaweekTV]

@ramiister01 The OPA132 is an Op Amp and requires a dual polarity power supply. Stick with the LM386 for audio.

[markusdnd]

But i can make it go to twelve!

Love the video!!!!

[dhruven1992]

does it give a good vol?

[dhruven1992]

does it give a good vol?

[iamtheug]

i know one could create a stereo amp by just doubling up the parts and connecting them to a stereo jack. would it be possible to consolidate some of the parts? or would that cause problems because each part is dealing with the signal from its own chip? obviously it would be rather tedious to have to adjust the volume for each channel.

[HackaweekTV]

@iamtheug The only shared component would be a dual volume potentiometer.

[MrHaakon386]

great video! do you know if that amp is good for a guitarsustainer amp?

[dinomaui]

@MrHaakon386 I don't see why not. Give it a try!

[foobarmaru]

Very cool!

[DaemonPanda]

Awesome!

[ExtremHybrid]

Wow...I love how you do your videos. It would be awesome if you would put up a link to version without speed-up so we could follow you in detail. (just my input).

Keep it up! Show those Hackaday guys!

[HackaweekTV]

@ExtremHybrid That would be a pretty long video, but I see your point. You can always pause and go a frame at a time so see more detail. :)

[ExtremHybrid]

@HackaweekTV Yes it would be a pretty long video. I just had to notice the few times you were holding the amplifier closer to the camera and you made gestures as if you were explaining something, but you didn't slow the video in those segments. If you were explaining something or doing similar things, just stoping the video & playing frame by frame wont retrieve that lost information.

Im not intending to rebuild you piece of engineering, but I just was thinking for all those newbies out there.

[ApexysThought]

Cool little amp. You could boost the power by adding an NPN transistor to it, but it's. loud anyway. What is the song in the intro called?

[HackaweekTV]

@ApexysThought "Shiny Spaceship" by 8-bit Ninjas :)

[KrelinLV]

@ApexysThought Thanks to this awesome video I searched for the song and uploaded it on my channel. :>

[TheMrSion]

I love this project. We're always looking for an amplifier at last minute parties - this would be great to keep in the car. I only wish they would start selling Altoids in the UK!

[doggiedoc94]

Very Cool! Way to keep 'em coming Maker-D!

[vk2zay]

I use double-sided foam tape for mounting PCBs in altoid tins insulates and gives some flexibility so the thin gauge metal bending won't break glue joints.

[HackaweekTV]

@vk2zay Good idea!

[jedreadproductions84]

FIRST COMMeNT!