0.Preface

I only have one speaker, and I have to connect it to a computer and a game console. It’s very troublesome to switch audio interfaces between different devices. HDMI has a switcher, so why isn’t audio? So this project came into being.

There are also USB+HUB 4-in and 4-out switches and HDMI 3-in and 1-out switch. Welcome to jump to each switch project:

Audio 4-to-1 switcher (common ground) (this project)

USB HUB switch 4 in and 4 out

HDMI3 in 1 out switch AG7111 chip verification board

1 Introduction

Audio switcher made using CD4052 digital signal/analog signal 1-to-4 switching chip.

CD4052 chip verification board

This design has been used in my ESP32 Bluetooth speaker before. Click here to view the previous project.

2.Use caution

Since this chip is a 2-channel 4-channel switch, it is designed with a common ground, and there may be a probability of audio crosstalk with each other (see the switching equipment, speakers and AUX lines) (Originally it was intended for SWITCH, but the handheld mode does not Problem, there is interference when plugging in the base, but replacing the speaker works fine) . A different design will be released in the future, so stay tuned.

This design is only used for switching and cannot be used for frequency division.

3. Market

There are relatively few people selling this stuff online on Jack Ma, and it's quite expensive. The cost of the solution I designed is only less than 8 yuan (remember, I do PCB twice a month).

The switching chip costs about 1 yuan each, and the logic chip costs a few cents. Plus switches, audio jacks, potentiometers, and buttons, it is actually relatively simple to make.

4.Principle

It is relatively simple, just use two buttons to control, and the chip will switch when it recognizes high level and low level.

The LED indicator uses a logic chip 74HC139 decoder to control the switching indicator.

5. Suggestions for improving crosstalk

1. Add DC coupling capacitors to both input and output. (Input and output 100 ohm changed to 4.7uF capacitor)

2. Add a 100uF decoupling capacitor to the IC power supply pin.

3. Change the analog ground to single-point grounding.

6.Finally

See the video for actual results.

The shell is waiting to be painted. It may or may not be painted. I will see if I have time for the next painting.

HDMI switcher is also on the agenda! There is only one screen, so switching back and forth is too troublesome!