This post covers a bit of an old project, but I wanted to write about how I made my 3.5mm audio switch.
The goal of this project was to make an audio switch that had multiple inputs and multiple outputs.
At the time, I could not find a commercial product that did this, and similar DIY projects only had multiple inputs and a single output rather than numerous inputs and outputs.

I started this project by making a wiring schematic.

![Wiring diagram on white board](media/aux/board.jpg)

The goal is to toggle 3.5 mm ports on or off and have their left, right, and ground lines accessible via a bus that is available to all the other 3.5 mm ports.
To toggle sources on/off, I used a latching push button.

If I were to do this project again, I would 3D print a case to house all the elements; however, I didn't have that luxury back in high school.
To create a sturdy container for the wiring, I drilled 12 holes into a thin metal piece.
The 3.5 mm jacks got screwed into place with a provided bolt, and the toggle buttons were hot glued to the piece of metal.

![soldering after finished](media/aux/soldering.jpg)


After soldering, I attached the metal piece to the front of a gutted CD drive.
The CD case enabled me to mount this the front of my computer, making it easier to transport and put it close to all my audio equipment.


![](media/aux/computer.jpg)


Recently, I have used this on top of my desk rather than inside my computer. 
I have my laptop, desktop, record player, headphones, and speakers hooked up to it.

![On desk](media/aux/desk.jpg)


Since all the wires are not totally insulated, the audio isn't studio quality.
However, the audio doesn't have any noticeable interference and sound great with my headphones.