Having just started with Transistor radios, it's amazing how many there are in varying sizes.

This Dynamic Mic Preamp is powered by a FM radio that originally was powered by 2 AAA batteries. So USB power is cool, with 2 22Ohm resistors (in parallel).

I desoldered the 20K Ohm pot and replaced it with a panel mount version, put a 1/4 Jack in plus have hardware ready to install for outputs and power led.

Not only can I use my Dynamic Mics, I can now test them plus I can design new dynamic Mics by testing various speakers.

Why pay big bucks for dynamic mics when thrift shops have them? Some may need repair, but I now have a setup that works, and I didn't have to spend big bucks on a retail job.

I have one more FM radio I can build a pre amp with, plus I will try and make a guide if folks want to try this out.