Mini Stereo Amplifier





Introduction: Mini Stereo Amplifier

Hello everyone, I'm back again with my new electronics projects!. In this Instructables i will show you how to build a MINI STEREO AMPLIFIER from a cheap parts. The cost is under 5 $ !!.

This amplifier is mini size, so you can place this in your pocket, wallet, or bag. This amplifier is portable, so you can use this anywhere, anytime or even anyplace. You just connect the speaker to this amplifier and Voila!, the sound is powerfull!!

No more talking, Lets Build it!!

Step 1: You Will Need:

  • PAM 8403
  • A Case (i using old voltmeter case)
  • Usb male
  • 3.5mm stereo Audio jack
  • 2 RCA socket (Red and Black)
  • Some wire
  • Glue, I'am using Epoxy glue


  • Soldering iron
  • Sandpaper
  • Knife or scissors

Step 2: Make the Case

  • Specify the location for the PAM 8403, RCA socket, USB, and Audio jack
  • Next, i make a hole using my soldering iron for the RCA socket
  • For make a hole for USB, i'am using knife to make the hole
  • Next, i take sandpaper and make the case soft using this.

Step 3: Gluing Time

  • Because i'am using epoxy glue, i need to mix the two parts.
  • Next, insert the RCA socket into the hole that you made (Black left and Right red) and glue it. Wait until 5 minutes or more to make the epoxy dry.
  • After finish gluing the RCA socket, take the USB, glue it, and place it to the hole for USB.
  • Wait until the glue dry.

If the glue is dry, insert RCA socket to the hole that you made. next, we need to solder the all parts to make the amplifier. OK lets solder it.

Step 4: Solder All of the Parts

The circuit is like this:

  1. Input audio (White = Left, Yellow = Gnd, Red = Right)
  2. Input power (Black = negative, Red = positive), USB (Left corner is positive and Right corner is negative)
  3. Audio output left (Black = negative, Red = positive)
  4. Audio output right (Black = negative, Red = positive)

Solder all of the circuit. I recommend you to use small cables, because the case is small, so the cables fit to the inside of the case. After you finish solder the circuit, lets finish this

Step 5: Almost Done

After you finish soldering the circuit, next insert all of the circuit to the case, and close the case. I'am using cardboard to close the back of the case, but you can use plastic or anything. After all, now your Mini Stereo Amplifier is finish and ready to test it.

How to test this??

  1. Insert the USB to Dc 5v adaptor and connect this to electricity in your home;
  2. Insert the audio jack to your phone,
  3. Take you speaker and connect it to RCA socket (black is left speaker and red is right speaker),
  4. After that, Play any music on your phone
  5. And the sound is Very Goood!!!

And now you have your Mini Stereo Amplifier.

Thanks for look my work. I hope you like this.

Please Like, Share, Subscribe or vote this.

Happy making, Thanks



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    What size speakers does this work with? (Watts/Ohms) Thank you!

    Thanks for look my works.

    The output for the speaker is 3W and 4Ω.

    Awesome! thank you! Also is there a way to set it up to run on a couple 18650 batteries? I can't quite figure out how to get them to 5 volts easily. But i have a ton of them and i want to use them.

    If you want to powered this using battery, you can use 5v dc boost converter

    Thank you for the help. I'm having a hard time finding one that I know will work. Do you have a design in mind? Or one to buy? Or would 7 or 8 volts harm the project?

    Hi. i know a bit about datasheets and Li-ion so i can answer your question!

    The datasheet says that the PAM8403 has a supply range of 2.5 to 5.5v. So you can power it directly from a single li-ion battery. Tough at 3.6v the power output is halved.

    if you really want to get a neat 5v for this and other projects then you can either use a boost-converter to get 5v out of a single cell or use a simple regulator to get 5v out of 2 batteries in series. The regulator is the most easy one as a single component can do it. For a boost converter there is the LT1308 and for standard regulator there is the ultra-common 7805.

    Slight warning: Li-ion is not the most safe of batteries. If yours doesn't have integrated security be careful to avoid short-circuit or discharging below 3v!!

    Extremely helpful answer, thank you! I'm tying to learn as fast as i can. Can't wait to make this

    No problem. Electronics is a major hobby of mine (to be specific i have a passion for audio stuff like headphone amplifiers and retro stuff like Nixies and vacuum tubes) so if you need any help or want to know how to do something feel free to ask!! :)

    I certainly will and I share your passion. But I'd say I've always been more of a tinkerer than a builder. Looking to move up a bit and start building more purposefully.

    You can use a 3v to 5v step up module. You can buy that on ebay.