FAQ_MA35_Family Adjust Volume Noise Problem

[yhcheng3]

Question :

MA35D1 Adjust Volume Noise Problem


Answer.
Turn on the NAU88L24 DAC Zero Crossing function.
See nau8824 registers below:

voice.PNG (691.75 KiB) Viewed 930 times

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Use amixer to enable the Headphone Zero Crossing function of the audio codec.

The command:

Code: Select all

$ amixer cset numid=xx 1

* xx is the number id of Headphone ZC Switch
**numid can use the amixer control command to search for 'Headphone ZC Switch' to get the corresponding number id.

For example:

Code: Select all

$ amixer controls

numid=28,iface=MIXER,name='Headphone ZC Switch'
numid=30,iface=MIXER,name='Headphone Volume'
numid=29,iface=MIXER,name='Headphone Playback Switch'
numid=6,iface=MIXER,name='PCM Volume'
numid=37,iface=MIXER,name='Aux Boost Volume'
numid=39,iface=MIXER,name='ADC 128x Oversampling Switch'
numid=1,iface=MIXER,name='ADC Companding'

Code: Select all

$ amixer cset numid=28 1

numid=28,iface=MIXER,name='Headphone ZC Switch'
  ; type=BOOLEAN,access=rw------,values=2
  : values=on,on
#

2. When modifying the volume, use the method of gradually increasing or decreasing.

For example, the current volume is 1, and if you want to adjust it to 10, you need to gradually increase it from 1, 2, 3, 4... to 10.
Whether you want to change the codec or the SOC, you need gradients.


#MA35 , #DDR #buildroot #ma35d16ab1a
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