LM386 Microphone Amplifier

I purchased these modules a long time ago when I was needing a simple low voltage amplifier. I did not use them as I settled on another LM386 module.

This module is a little different in that it is marked as having a "Mic" input. I could not easily locate a specific schematic for this board, so I have reverse engineered it. The input section was not as I had expected. The module appears to have a 10K pull up and 2 different value capacitors in series.

The trimmer is not in the input path as with many of the other modules I bought. Instead it is being used to adjust the gain of the module. The LM386 has a gain of between 20 and 200.

LM386 Microphone Amplifier Module Schematic PDF

LM386 Microphone Amplifier Module Schematic SVG

LM386 Datasheet