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Make: Projects

Small Amp

Simple LM386 Amp circuit that's powered by a 9v battery and some ways to encase it.

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  • Category: Music
  • Time Required: 5 hours
  • Difficulty:
  • Difficulty:
Small Amp

This was one of the first circuits that got me into making. It’s very simple and can be used to amplify audio output (mp3 player, computer, etc.) as well as electric guitars.

Steps

Step #1:

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Small Amp
  • Here is a sketch of the circuit I use. It's not drawn in any traditional sense. But it helped me visualize what I was trying to accomplish.
  • The 10uf cap marked "optional" is best left out unless you're looking to use this as a guitar amp.

Step #2:

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Small Amp
  • Lay out the circuit on the perfboard.
  • Make a rough guess at how much board you need.
  • Score your board several times with the X-acto knife and break off what you need.

Step #3:

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  • With everything in place, bend the leads of the components to accommodate soldering.
  • Leave the LM386 out of the socket so as not to burn it up with heat (personal experience).
  • Solder away!

Step #4:

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  • Add a power source (9 volt battery)
  • Audio Jack
  • and speaker(s)

Step #5:

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  • Test circuit.
  • Add any last-minute items (on/off switch, LEDs, etc.).

Step #6:

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  • Build an encasement.
  • I am not promoting smoking,
  • But this is a very easy and compact project box.

Step #7:

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Assemble with hot glue.


  • Alek

    Yeah like I said the schematic is not drawn in any traditional sense. Its more of a note of what to solder where. I should probably fix it one day. Thanks for the input and correction.

  • Alek

    I haven’t been doing much with electronics lately, but it sounds like you may have burn’t up the LM386 during soldering. I did this twice before I realized what was happening. Other than that check some other specs online, this is just one example, and good luck to ya.

  • routh

    can I use a jrc4558d??? I don’t know much about Ics or circuits,its just that I’ve a couple of them lying around so…?!

  • Cameron

    Would I be able to add a 10w 8Ohm speaker to it without having to change anything?

  • RANJITH KUMAR

    nice one..

  • http://y Michelle

    Hi Alek, What is the size of the speaker you used, watts, and ohms?

  • http://yahoo yugansh

    pls make a circiut in correct way with corret symbol

  • zazacd

    can i change LM 368 with someone else