Constructing a homemade microphone

To create a simple homemade microphone you need only a bunch of common electronic elements and a solder. Today I will present, how this microphone can be built at home.

homemade computer microfone

Below is a sample track recorded by this microphone.

We will use electret microphone, it's cheap and popular but it can't be plugged directly - it requires a simple circuit, that is presented below. R1 polarizes the microphone, C1 removes noise from power source, C2 isolates sound card from constant current in the circuit.

circuit of homemade computer microphone

List of elements:

  • R1, 10k
  • C1, 220u, 25V
  • C2, 100n
  • M, electret microphone

Usually microphones are connected to other devices (for example into the computer) by using a jack plug, the same plug is used headphones, so we can obtain it from old, broken headphones. I presented this also in "Constructing a homemade speaker" article. Below is shown how to correctly connect this cable to our microphone circuit.

homemade microphone - jack plug

The microphone can be obtained from an old recorder, mp3 player or similar device. Rest of the elements can be also obtained this way.

how to build a microphone at home a microphone for a PC constructed at home

That's all, I hope that it will be useful for you!

18 comments:

  1. thank you so much. it worked for me but could you tell me what would happen if r1 is decreased or increased ?

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    Replies
    1. R1 gives current for condenser mic.if remove it,it will not work.if increase value of R1,condenser mic get lower voltage than before.therefore,sensitivity of mic become low.

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  2. Hi,

    if its resistance will be to high, then microphone will not be fully polarized and the sound will be to low. It's a simple circuit and values of elements may be changed in wide range.

    kind regards,
    Robert Gawron

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  3. C1, 220u, 25V
    C2, 100n

    For these capacitors (I assume they are capacitors) is it a 220 microfarad capacitor and a 100 nano capicitor?

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    Replies
    1. Hi Scott,

      yes, you're right.

      regards,
      Robert Gawron

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  4. @scott
    Yeah.. u r correct we are using Capacitor and resistor in circuit.. so basically its an RC circuit.

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  5. What happens if I change the resistor with a 5k or 10k potentiometer?
    In this case I can adjust the mic volume, or I am wrong?
    I apologyze for my bad language ;)

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  6. It's me again.
    Look at this schematic
    http://i41.tinypic.com/2qizp86.png
    I have added a potentiometer in series to the original resistor, I think it's a better way to adjust the volume.
    The resistor value can never be smaller than R1, only bigger.
    On my last post I have forgotten to thank you, sorry

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    Replies
    1. Hi,

      R1 is used to polarize the microphone, changing its value shouldn't change significantly the amplitude of the signal. I think that what you're searching is "microphone amplifier circuit" - you can find a lot of them in Google Images and combine one of them with the circuit presented here.

      kind regards,
      Robert Gawron

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  7. This is the best one I found!

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  8. Thank you. After I built this, the sound quality took my by surprise.

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  9. wow, simple and power full,,thanks for your share mic, ilke this

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  10. hmm should give a try ,hope this doesn't produce a big hum!

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  11. Hi! Why the voltage rating is precisely 25 volts? Would 220uF10V capacitor suffice? Very nice guide btw!

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    Replies
    1. Hi,

      The voltage is around 5V DC, so 10V cap willl do the job too.

      Bob

      Bob

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