Gunther Cox Simple yet powerful audio amplifier

Simple yet powerful audio amplifier

Introducing Simple Amp!
This simple yet powerful audio amplifier is an ideal DIY electronics project. Using a minimum of four parts you can build an amplifier that will put commercial sound systems to shame. Not only is this amp powerful, but it is compact, able to fit in an Altoids tin with room to spare! Check out these instructions on how to build your own.


  1. Nice instruction! I intend to recreate this.

    One note: on page 4 after the title page, you say "About the LM683". I didnt notice until later in the show that they were 386's

  2. Thanks and good catch. That was a typo and it has been corrected.

  3. Michael Pfleegor2/20/2014

    Would it be possible to get a picture of the bottom of the completed board???
    Great Project...
    Thank You

  4. Hi Michale, here is a picture of bottom of the board. I've positioned it such the at side with the battery connection is facing upward. Let me know if you need any more information.

  5. I tried to build this as well, but getting some feedback and noise. Either my connections are bad or my speaker is. I purchased a speaker from digikey

    Part # 102-1551-ND
    Description: SPEAKER 8OHMS .5W 40MM 6" LEADS

    Did I miss read something?

  6. Hi Eric, it looks like the voltage requirement for your speaker is lower than the one I used. This isn't a problem, you just need to add a resistor between the battery and the circuit board. I believe that a 400K ohm resistor might be just what you need.

  7. WOW, Thanks for getting back to me so fast. I just went on-line to digikey and a 400k ohm resistor is a little over $3 and a 1.5W speaker is $4. I would rather spend the money on a speaker than a resistor. is a 1.5W speaker big enough? If not than I will go the resistor route, but for the future what are the specs of the speaker?. Again thanks for the help. Much appreciated.

  8. I'm using an 8 ohm, 2 watt speaker. The slightly lower wattage shouldn't make a difference because I have used this amp with much smaller speakers than that. You may want to consider getting a potentiometer so you can adjust the voltage input to exactly what you need ( Also, what kind of audio device are you plugging this into? Try lowering the volume on the whatever device it is and see if that helps. Assuming that the circuit is working correctly, the white noise you are getting is due to a higher amount of input than it is expecting. This circuit can handle a broad range of speakers, but it requires very little voltage for input.