Mini Audio Amp

Introduction: Mini Audio Amp

About: Jungles my home _ College now my life _ Mechanical Engineer to be _ An adventurer at heart

Greetings and salutations.  The truly mini audio amp has finally arrived!  It is a cute, pocket size, multi-purpose audio amp that just about everyone needs.  The main purpose of its creation was to listen via headphones to my guitar playing.   It also will amplify guitar playing enough to transmit it wireless though a FM transmitter.   Another feature is a small speaker built in for amplifying a mp3 player or such.  Being the person I am, (bio) I go cheap on my projects.  This project cost me the grand total of three dollars, but could cost you a LOT less.  I kept this amplifier extremely simple, so pretty much anyone can do it.  I hope you enjoy. 

This is my first instructables so I would appreciate any tips or comments you might have.  Feel free to ask questions at the bottom.  I will try to answer them quickly.  I would also appreciate it if you vote for me.  All right, intructable time!

Disclaimer:  I am not responsible in any way for any hurt you may get from making this project or using it. 

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Step 1: Gather Parts and Tools

As I said this amplifier is extremely simple and cheap to make.  

The parts are:

(1)  LM 386  ic  (I got mine at Radio Shack) Just type it into the net and you will get plenty of results. 
(2)  Battery  (3-9 volts)  (I used a cell phone battery.) 
(3)  A small casing (I used a small mint tin)  -  it was almost to small.  An Altoids tin would be perfect, but in my jungle town I don't 
        know of any place that sells them.  I use whatever I can find. 
(4) Two 3.5mm input jacks.  (I got mine from an old circuit board that I got at a thrift store the last time I was in the U.S.)
(5)  Wire - the thinner the better.  (I got mine from an old printer cable.)
(6)  A potentiometer (pot)  -  the smaller the better.  (mine was a 100 ohm pot)
(7)  Some sort of charging port.
(8)  A small switch
(9)  A small speaker.  (I don't know what type mine was.  I got it from a old circuit board.)
(10)  Optional  -  A 3.5mm audio tip.  (I got mine from an old headset.)
(10)  That is it!

The tools are:

(1)  Soldering iron (And basic skill in using one,  but if you don't have the skill you need to start sometime.)
(2)  Drill or some way to make holes in the tin.
(3)  Wire strippers
(4)  Plumbers tape  (I like it to wrap thin wires with it.)
(5)  Helping hands are helpful. 

Lets get to the circuit!  It is simple!

Step 2:

You get the picture.  This isSIMPLE.

Step 3: Fabrication Time

If you need more pictures then just the circuit sheet, here they are.  I take TONS of pictures.  To many in my dad's opinion.  :) 

Step 4: Boxing Stage

This is the moment of truth.  You can now hook up everything and make sure this mess of wires works.  Mine worked great the first time I tested it. 

Step 5: Boring Stage - Literally

This is the stage you fit everything in the tin and figure out where you need holes.  This is also the stage where I gave my ugly tin a nice little paint job.  The paint didn't come out so smooth, but it looks better.  So, get busy and paint that tin up. 

I thought the tin casing I used would be able to hold everything, but with the added speaker and the size of the battery.  It wouldn't quite close  -  thus the rubber band.  :)  If you have a smaller battery it would be great.

Step 6: Cramming Stage

Now its time to cram everything in this little tin.  Almost done!

Step 7: Finished

Finished!  Have fun using your new amp!  If you have problems or need help just ask.  I would appreciate any suggestions as this is my first instructables.  I am not the greatest writer, but I hope you understood.  Have fun and remember to vote!

Until next time,

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    5 Discussions

    Thanks for the advice out-of-the-box. (I can't get the reply to you to work.) I never had much of a problem using cell phone batteries in my projects, but do notice they get hot sometimes. I assumed using a cell phone charger to charge them would be the same as they were being charged in a phone, but I guess I am wrong. I don't have access to many parts, and so I am constantly making do with other parts. I appreciate advice since I am not very experience yet. Thanks.


    Reply 6 years ago on Introduction

    No problem :) I make do with what I have aswell just thought I would give a small heads up. most cell phone batteries are li-ion and they pose a great risk if discharged improperly. Good job on this project! I love how compact it is.

    cell phone batteries can be very dangerous if you charge an discharge them improperly. I would recommend using a charge controller it prevent the battery from over charging and even exploding. y suggestion is to use a nickle based rechargeable battery. Great job on your first instructable!