Low noise Mini Electret Microphone PreAmplifier

  • Rajkumar Sharma
  • 39.506 Views
  • easy
  • Tested

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The single supply microphone pre-amplifier amplifies the output signal of an electret capsule microphone to audio line levels. An op amp is used as a trans-impedance amplifier to convert the output current from the microphone in to a signal level voltage. The circuit works with 9V so it is good choice for battery operated systems.

Features

  • Supply 9V DC
  • Current Approx. 3mA
  • On Board Microphone
  • Very thin and narrow PCB

Schematic

Parts List

bom

Photos

img_5974

Video

OPA172 Datasheet

opa172

PCB

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JensJ

Thank you for this. Modified it to run on a 5V supply and using another OP-Amp and it works perfectly with those alterations.

Dan Gonzalez

the capacitor C5 is well polarized in the diagram, or is it a misprint

kenahilton

I want to purchase the above microphone preamp. What is the cost in USD and how do I get it?

Javier

Hi! Is it possible to hear some real sound tests? is it possible to get a copy of this mounted for experimental purposes? thanks and good job!! 🙂

Phil Stewart

Hi,
I’m interested in several of these — more if they perform well.
How is performance in the presence of RF interference & nearby electrical devices? The PC board is pretty basic — does it require shielding?
I am interested in either the PC board or assembled device, depending on price. Thanks!

Simon Rung

Hi!
How much for an assembled device?
For now I’m in a prototyping face and i would like to try one of these out.

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