4 Pole Switch

[skitz1995]

Hey LTT community, I just got a Logitech G933 headset the other day and am curious whether I could do what is shown in the diagram below, but with ONLY 4 pole connectors so as at the flick of a switch I can go from being connected to my desktop, to laptop, to phone, to xbox one, and so on. Cheers in advance.

[mariushm]

Ready made solutions for that are called audio mixers. They take in multiple inputs and produce one output and allow you to control the volume and/or apply effects to individual inputs before being routed to outputs.

 

If you want something more dyi , there is a category of ICs called muxers - they have multiple input pins and one or several output pins and a few pins that select which input pin is connected to the output pin 

So since you have stereo headphones, you'd need two such chips, one for each channel. If you also want the microphone to be redirected, then you'd need one of those chips for the microphone as well.

 

Here's an example of such a chip would be MAX4617, one for each audio channel : https://www.digikey.com/product-detail/en/maxim-integrated/MAX4617CPE-/MAX4617CPE--ND/1780285

 

 

It's very simple ... Vcc is +5v , GND is ground (the negative wire from a usb cable for example) .. this is what powers the chip.

X0 to X7 are audio inputs (one audio channel, for example x0 could be left audio speaker from pc, x1 could be left audio channel from laptop, x2 could be left audio channel from phone and so on)

X is the output.

Enable pin is connected to ground to enable the pin. If it's not connected to ground, it behaves like a MUTE function, it disconnects X pin (the output) from everything.

Pins A, B and C tell the chip which of the X0 to X7 pins (inputs) to connect to the output pin X ... it's like working with a 3 digit binary number.

A binary 0 means pin connected to ground, a binary 1 means pin connected to 5v .

So if you want X0 to be connected to X, you need to set ABC to 000 , or basically all 3 pins connected to ground.

If you want X1 to be connected to X, you need to set ABC to 001, or basically A and B connected to ground and C connected to 5v

and so on .. the table is in the datasheet. 

Simply put it's like having to use 3 buttons with two states to select the input channel. Or, if you only need 4 inputs, you can leave the A pin always connected to ground and and just use two buttons or a slide switch to change the inputs : AB = 00, 01,10,11 for our x0..x3 -> x

 

So you'll have to use two, one for each audio channel , and naturally have two sets of switches, one for each audio channel.

You could simplify it to one slide switch or some knob if you find the right one, or if you use a microcontroller (an arduino board for example) for example to manage those 2 pairs of  pins simultaneously.

With an arduino you could have 8 push buttons and 8 leds one above each button. When you push the button, the arduino would light up the led above the button and then would connect the right input to the output of each chip at the same time (by sending 5v or 0v to each of those ABC pins).. and you could extend it to microphone as well.