Dual Input Audio Switching Circuit
Intro: Dual Input Audio Switching Circuit
Have you ever had the issue of having one speaker system and multiple inputs that require you to plug and unplug your audio leads each time you want to listen to one source? Well, I've got a solution for you! This Instructable is about making a very simple 3.5mm stereo audio switching circuit. All you need is a switch, a few audio sockets, an enclosure of some sort and some wires. In this Instructable, I've made a switching circuit for 2 inputs and one output, but this can easily be expanded to several inputs and one output by swapping out the switch and using more audio sockets. Let's get to it!
STEP 1: Get Your Parts Together
Here's what you're going to need for this project:
Tools:
Soldering iron
Wire stripper/side cutters
Hobby knife
Drill and drill bits
Materials
3x 3.5mm stereo audio sockets https://www.jaycar.com.au/3-5mm-stereo-chassis-soc...
1x DPDT switch
1x Sugru packet
1x small plastic enclosure
Small amount of wire
Small amount of glue
Solder
STEP 2: Prepare the Enclosure
Here we are going to drill out some holes so you can mount the audio sockets and the switch. Position the holes where you desire, I put the two audio inputs on one face and the audio output on the opposite face of the enclosure. I put the switch on the front face of the enclosure. Drill appropriate sized holes for the 3 audio sockets. The switch is a bit tricky to attach to the enclosure and I didn't do a very neat job of this... I first drilled a hole at the approximate centre of where I wanted to position the switch and then I ended up using the tip of the soldering iron to melt away the rest of the material. Unfortunately when I did this, it melted away a lot more material than I wanted and I was left with a hole that was bigger than the switch. To avoid this, I recommend marking out the switch beforehand and melting the plastic away gradually. Use a hobby knife to trim the excess plastic and make the face of the enclosure smooth.
STEP 3: Wire Up the Switch and Audio Sockets
I recommend soldering wires to the switch first and then soldering the other ends to the audio sockets. The switch I chose was a DPDT switch meaning it has 3 columns * 2 rows of pins. The two rows are for the left and right channels and the three columns are for your inputs and output. Keep in mind that the centre column pins on the slider switch are the output pins and the others are for your inputs. Make sure you measure out the wires so that there is plenty of length to reach from the space in the enclosure for the audio socket to the switch. What you're soldering here are the left and right channels only to the switch. Colour coding the wires helps to make sure you connect the correct wires to the correct pin on the audio socket. Solder all the ground pins of the audio sockets together via black wires and solder the left and right channels to the switch.
STEP 4: Fit the Audio Sockets and Switch Into the Enclosure
STEP 5: Close the Gaps With Some Sugru
STEP 6: Close the Box and Give It a Test!
Once you've connected your inputs and output, play with the switch and see which source belongs to which side of the switch. After you've figured this out, use some labels to mark the enclosure so you know which input is which.
So that's it, you're all done and ready to enjoy hassle free listening at the flick of a switch!
15 Comments
BurnerG 5 years ago
that 3pdt is actually a dpdt (double pole, double throw), it does not refer to row and column
lb_20 5 years ago
Indeed it is, thank you! At the time of writing this I was playing with a 3PDT switch as well for another project, must have got myself confused ;) Thanks for the comment, I'll fix up the description :)
BurnerG 5 years ago
you're welcome! :)
KdogK 7 years ago
I need help i want i use this switch and have two input with one output how do i do that
lb_20 7 years ago
This Instructable is for two inputs and one output so you should be able to just follow the steps here. Unless you are talking about having a single throw instead of a double for the switch?
GreenSh4dow 8 years ago
lb_20 8 years ago
GreenSh4dow 8 years ago
lb_20 8 years ago
This switch looks okay, I recommend looking at RS or Farnell in Germany (online) for other possible switches you can use.
GreenSh4dow 8 years ago
GreenSh4dow 8 years ago
JosephC64 8 years ago
can this be used with microphones?
lb_20 8 years ago
Hi, I don't see why not! I'm not very familiar with microphone connections but if they also have 3 wires (GND, L, R equivalents) then you can definitely connect two microphones to the inputs without having to use a different configuration of switch poles and throws.
xxxCHICAGOxxx 8 years ago
Cool I made something like this a little while ago! https://www.instructables.com/id/Audio-Input-Toggle-Switch/
lb_20 8 years ago
Nice one! It's such a simple, but practical project!