DIY Mic Circuit

Hi there,
I am totally new to this forum and am sorry in advance if this is not in the right subject area.

I have been struggling to decipher this guide and was hoping someone out there could let me know two things:

    • What circuit board I need to purchase to make this mic
    • I can just use two XLR cables I have kicking around (I have the Omnidirectional Microphone Cartridge (available from Digi-Key at 800-344-4539, part # P9959-ND))

Also I am attaching this to a stethoscope, so keeping it moderately small is a preference.

Thanks a bunch

Welcome to the forum.

That project does not use a PCB, everything is simply wired using the component leads and wires.

XLR balanced low impedance microphone cables are a standard cable, so the ones you have should work fine.

Have fun! This is the type of project I loved doing when I was a teenager back in the 1970s.

1 Like

Thank you Paul!!
I really appreciate your encouragement! Though I am still rather confused by the diagram on the website, and I am not sure how I would connect a power source.


Just to be crystal clear the only things I have to make this with are:

  1. The Omnidirectional Microphone
  2. Two basic XLR cables
  3. Soldering iron
  4. Stethoscope

I think I am missing something here

You have to build the power source as shown on the project page, it’s the schematic just below the one you posted. You’ll also need to buy the parts listed for the power supply on the project page.

The microphone connects to the power supply via an XLR cable and the power supply connects to a balanced XLR microphone input on your mixer via the other XLR cable.

Thank you Paul!!
But that is unfortunatly where I have to completely stop the project because I cannot read the schematic. It is just to confusing for me to follow it correctly.
The list of the additional parts after The Omnidirectional Microphone are also too foreign for me to understand how to connect them or anything.

Thanks for your kind words but much like getting a little bit of help in math class, I am just going to have to flunk this one hahaha