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Reducing pops between tracks MAX98357

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(@gorek)
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Joined: 2 years ago
Posts: 8
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I connected MAX98357 to my RPi4.
Because drivers are already in kernel I just add below line to /boot/config.txt 

dtoverlay=max98357a,no-sdmode

and everything works fine except annoying pops and clicks when I start playing or changing track.

The reason of these noises is described in this post:
https://forums.adafruit.com/viewtopic.php?f=50&t=104049

Simplest solution is just play silence to avoid I2S clock frequency changes, and perfect will be play it after system starts.
To do this I created small systemd service as below:

[Unit]
Description=Invoke aplay from /dev/zero at system start.

[Service]
ExecStart=/usr/bin/aplay -D default -t raw -r 44100 -c 2 -f S16_LE /dev/zero

[Install]
WantedBy=multi-user.target

But after I ran this service nothing's changed (I still hear noise after changing tracks).

When I just run "/usr/bin/aplay -D default -t raw -r 44100 -c 2 -f S16_LE /dev/zero &" issue with noises is resolved.

What am I doing wrong?
How should I configure this service to eliminate noises?


   
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byron
(@byron)
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Joined: 5 years ago
Posts: 1135
 

Posted by: @gorek

What am I doing wrong?
How should I configure this service to eliminate noises?

I cant help on this as I've not played much with the sound on the rpi.  But I think you will find more help if you put your question in the rpi forums. https://forums.raspberrypi.com/index.php


   
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