Arduino Audio Switch

About: come visit me!

Inside my shelter i've a 5.1 Bose surround system and a couple of Yamaha NS-10M Studio speakers. I needed to drive them with only one power amplifier, so i needed a custom audio switch between speakers and LFE too. Instead of a typical mechanic switch i've found an easy solution using an Arduino Pro Mini and a 8ch relay module.

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Step 1: 5.1, 2.1 or 2.0 ?

Pushing its button, arduino audio switch let me give three options to listen amplifier audio output :

1) 2 channel mode through Yamaha speakers

2) 2+1 channel mode through Yamaha speakers and BOSE LFE

3) 5+1 channel mode through BOSE 5.1 surround system

I put point one first. This means that, when system is not powered i can listen music through Yamaha speakers, because this is my common use.

When i give power supply, i can switch between the three options above mentioned.

Step 2: Here All That You Need

This project can be basically performed with:

8ch 5V relay module

Arduino Pro Mini


3xled (optional)

1x220 ohm resistor

1x330 ohm resistor (optional)


5x7 Prototyping board

You can also add your customized enclosure box and input power supply with related on/off button, as i have.

Obviously you'll need a solder for PCB assembling and something to model your enclosure box.

Step 3: Assembling

Assembling of the switch box is very easy.

Connect amp and speakers cables directly to relay or trought terminal block, as i have.

Then relay module to Arduino as showed on schematic.

Do not use Arduino VCC pin to drive 8ch relay. Connect relay module VCC directly to 5V and GND to common Arduino ground.

The one that i've made draw 5V from PC USB cable because i've adopted an Arduino Pro Mini with RAW pin burned, so with PC stabilized 5V output i can easly drive Arduino and relay module togheter.

Step 4:

Load the sketch and.... enjoy.

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    7 Discussions


    4 months ago

    Do you hear something like a crack, when you switch while playing music?

    1 reply

    Reply 4 months ago

    No, never. I heard just a relay click sound when change input source.
    Re-try to check your connections


    1 year ago

    Have these magnetic relays any effect on the sound quality?

    1 reply

    Reply 1 year ago

    No notable differences after adopting it

    but an audio purist would have something to say about that.


    1 year ago

    Are you able to do something like the following. Let's say you had two input sources and you wanted to be able to send one of the signals to 2 amplifiers, and one of the signals to a 3rd amplifier, or you wanted to just send one input to ALL of your amplifiers. Could you do that with a relay like this?

    1 reply

    Reply 1 year ago

    Hello Arretx

    project working principle is to switch an amplified audio signal toward their respective speaker sets. I think that what you need could be made redrawing complitely relay inputs and outputs channels.


    2 years ago

    Awesome, thanks for sharing!