Problem: Oftentimes on my desktop I need to use headphones for games or listening to music while other people are in the room and then I need to switch to speakers if I want to show off a funny video or make a Internet call to a distant relative. The problem lie with the switching where I have to crawl under my desk to switch out the cords for speakers and headphones. I decided a simple desktop audio switch would be the solution.
Purpose: To allow for selection from an audio input to one of two audio outputs.
Other uses: To allow for selection From one of two audio inputs to an audio output.
Step 1: Materials and Tools
1 double pole double throw switch. approximately 2.99 at radio shack.
3 3.5mm stereo audio ports. 2.99 for a pack of 2 at radio shack
some electrical tape.
small box or or mint tin. I used an ice breakers plastic mint container for ease of cutting.
lengths of wire.
Needle nose pliers
exact-o knife or similar cutting tools.
wire cuter (optional, an exact-o will work if your good with your hands)
Step 2: Prepare the Container
Position and size up where you need to make holes for your switch and audio jacks. I use a knife to cut the rectangular holes and after trying to do the same with the first round hole I decided to try a drill press and it worked much better. The lid also needed to be cut to accommodate the parts.
Depending on your materials and preferences location and sizes of the holes will vary. If I do this project over again I would separate the audio holes more as the connectors this close make it hard to reach the wires.
Step 3: Preparing the Switch and Audio Ports
At this point you can solder short lengths of wire to the leads of the audio ports and switch to make assembly and final connections easier. Wrap all leads in electrical tape to prevent shorting.
Step 4: Mount the Components
The audio connectors will slip into the hole and a nut keeps it tight in place. The way my switch worked I needed to hot glue a toothpick to the back of it and then to the container.
Step 5: Finnish Soldering and Closing It Up
Solder the neutral wires together and the left and right wires to the switch. If your switch has 3 poles you can solder the neutral wires there too. You only need know which wire is neutral. Just make sure to connect the same wire to the same pole of the switch.
Once all the wires are soldered replace the lid and tape it up and test it. I didn't notice any audio degradation with my box though there is always a chance some will occur.
I've added a wiring diagram to show exactly how I did this. Exactly which connection is left or right makes no difference as long as you are consistent. The ground is usually located on the side of the jack.
Step 6: Improvements and More.
Here are some ideas on how to improve or expand this handy device.
With more switches and audio jacks its possible to expand this for more inputs/outputs where each additional switch adds room for one more connector.
A larger switch with 3 poles instead of two and some spare audio cord may help to reduce any signal degradation.
Connecting the center leads of two switches will allow selection of multiple inputs as well as outputs.
If your wire is more flexible or your confident with your skills you can connect a single wire from each connector directly to the switch eliminating that center soldering point.
All comments and suggestions welcome.