Simple 9V 4 channel Mic mixer

Here’s an improved version of my simple mic mixer featured on this page. It is powered by 9V battery so you can make it portable.

About the circuit

The circuit is made of transistors only to make it simple. I didn’t use any op-amps on this project. You can basically build this circuit using universal PCB’s

It has 5 potentiometers. 1 for each channels and 1 for master volume. It can be used for guitars and mics.

Circuit Simulation

For simulation I used signal generator set with sinewave output at 50mV and each are set at different frequencies.  This is to be able to see each frequency on the output waveform. As you can see on the simulation of the output waveform, it has different frequencies.


PCB design

Here’s a simple PCB design that I made. As you can see, the design is very simple and only has few components. The layout is not perfect but at you can have something to start to. You can still improve this layout. 🙂

3D render by Kicad

You can download the Kicad project file here:

Download page <- find the download here