Sharing music is fun. Sharing earwax is not.

That's where audio splitters come in. With a single audio input split into two output sockets, this audio splitter can let both you and a friend plug in and listen to the same music at once. And it's housed in a cute little mini-Altoids tin for easy carrying! This instructable will show you how to make your own audio splitter using scrap electronics parts.

Supplies

You're gonna need:

An old pair of earphones to pull the 3.5mm male audio plug from
3.5mm sockets x2 (I desoldered both of mine from an old iHome)
Mini Altoids tin
Prototype perfboard
Solder
Hot Glue

Step 1: Prep the Components

One of the sockets I desoldered from an old iHome is shown above. The socket has a left and right channel as well as a ground (labelled in the photo). I had to test which channel was which by using alligator clips to hook up the socket to a speaker and playing music through it. In order for both the sockets to receive the same audio, the left channels of both sockets need to be connected to each other, the right channels need to be connected to each other, and the grounds need to be connected to each other.

The input from the headphone plug also needs to be connected to these channels. Strip the shielding from the headphone wires. In a headphone cable carrying stereo audio, there will likely be two sleaves, each carrying one signal wire and one ground wire. The close up shows that my audio cable has a blue-enameled wire and an unenameled wire together in one sleave and a red-enameled wire and unenameled wire together in the other sleave. The blue wire is the left signal wire and the red wire is the right signal wire. The unenameled wires are the ground wires (they are the same ground). In the next step, the signal channels and the ground will have to be connected to the corresponding channels of the sockets.

Step 2: Solder the Components

On the perfboard, solder the corresponding channels and the grounds of each socket together. Then solder the signal channels from the headphone wires to the correct left and right channels of the sockets and the ground of the headphone wire to the ground of the sockets. Before soldering the left and right signal wires, remember to strip the insulating colored enamel from the ends of the wires. This can be done simply by scraping the enamel off with an X-Acto knife. I went ahead and put a big glob of hot glue on the wires after soldering them. The wires connected to the headphone jack are very thin and fragile, so the hot glue insulates them from both electricity and any physical stresses.

At this point, check to make sure the splitter functions. Plug earbuds into each of the two sockets and plug the headphone jack into your phone or computer. Play some music. You should be able to hear it from both sets of earbuds. The audio may be slightly quieter because the same amount of power is being split across two earbuds.

Step 3: House the Electronics

To house the audio splitter, I stuck it inside a mini Altoids tin.The perfboard with sockets on it was hot-glued to the bottom of the tin. Two small holes were drilled in the side of the tin for the sockets. The audio jack and wire were routed through a small cut in the side.

The audio jack is stored inside the tin, so when not in use it looks like a normal mint tin. To use the splitter, open the lid, pull out the jack, route it through the slot in the side, and close the lid again. Then simply plug your device and earbuds into the jack and the sockets and you're ready to share some music! Enjoy!