Author Options:

Audio switch with four inputs and push button toggle? Answered

I'm looking to create a device similar to this instructable: https://www.instructables.com/id/Audio-switch-2-inputs-1-output/

owever I need four inputs and I would be using a push button as the means to jump between inputs. If I could also have some sort of indicator LED that would be helpful. Not quite sure how to tackle this project.



3 years ago

Why bother with crap semiconductors? Just use a nice clunkin' multi-position rotary switch!



If you really wanted to use a semiconductor part, you could look into multiplexer chips, as their sole purpose is to to exactly that: switch between 4 signals, only passing one though. That is a pretty broad and vague description, and the exact chip mentioned below (the 74HCT4016) would probably be the most suitable.

You could even go the discrete transistor path and design that from scratch, I can't imagine it would be too hard, only issue that may come up is how the transistor is used to pass the signal, and how it may clip or distort based on methodology used to drive it, bias it, etc.

If I go the rotary switch route, I would be looking for a three pole, four position?

Is the audio mono? or stereo?

Selecting the right switch can be confusing. You need to get one with at least 4 positions (many of the switches actually have many more positions than that, and you can use a little nut to limit it. That allows flexibility in design.) and the right number of poles for each audio channel.

(for basic stereo, w/ just a left and right speaker, thats 2 poles. To the wiper, that is the audio output, and that sweeps across all the inputs. The same goes for the wiper for the other channel. That is how different inputs are selected. All the ground terminals can be commoned together. Although it may be better or required by your application if the grounds off all the audio sources were not connected together.)

I would look for a 2P4T switch. If only dealing with mono inputs, a basic SP4T or 1P4T switch can be used.

For serious audio, there are silicon parts from people like Maxim, like the MAX4932 for a DIY job, you can use a mechanical switch.

I wouldn't put a 4016 anywhere near an audio signal with any kind of 'fi.

Google 74HCT4016. There are other options, but it's a good start.

Or just google "quad audio switch semiconductor"

Then you will need to use a micro controller to read the push button and toggle relays to switch between the inputs.