question about audio switch.

Discussion in 'General Electronics Chat' started by quintaar, May 6, 2016.

  1. quintaar

    Thread Starter New Member

    Apr 28, 2016
    I'm looking for some info, so I could google further, few posts on here refer to an opposite situation so I'm asking the question.
    I would like to try to create a switch/relay. There would be a single audio source (headphone jack 3.5mm) which I would like to route to up to 3 different outputs. These will connect to various speakers with built in amp. The goal is to use GPIO on raspberry to drive the changes and select correct output(s).

    I need ability to control what output is selected, i need to be able to route audio to all 3 outputs at the same time or any given 2. I want to use less than 3 GPIO if possible, I have no limits on parts used.

    Questions (I'm not looking for a ready solution - i like a good puzzle)

    If i understand this correctly I would be able to output audio to 3 devices without need for an amplification? (since headphones splitters work ok?)
    What would be the best approach? Relays? or some sort of transistor switches?
    Anything i should be mindful of when working with audio like this? (specific interference problems etc)
    Would it be possible to use just one GPIO to drive the changes with some sort of timer ?

    I would appreciate your input to my output issues!
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    You could use a cd4016 quad switch to feed the audio signals, they need 5v signal to close the switch.
  3. AnalogKid

    Distinguished Member

    Aug 1, 2013
    Your two basic choices are relays or solid state analog switches. Maxim and Linear Technology have many analog switch chips specifically designed for audio signals, but many of them require bipolar power supplies for audio centered about ground. Relays are fine, and don't care about DC offsets or bipolar power supplies, but are larger, require more drive power, and can introduce clicks into the audio. Since you have an Arduino already, I suggest using it to do all of the controlling with three I/O lines, rather than combining the controls into some form of coded protocol on a single I/O pin that then has to be decoded to drive the three switches.

  4. Ramussons

    Active Member

    May 3, 2013
    You could also use Diode Switches as a Multiplexer depending on the signal levels being switched.
  5. quintaar

    Thread Starter New Member

    Apr 28, 2016
    Thank you guys, I will start to research the resolutions suggested, will get back to you if anything seems unclear!