Hum/noise when not playing

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Hi,
I have hifiberry DAC+ Pro with Raspberry 3. If it's connected to amp and playback is stopped I can hear hum from speakers. If playing any song even very quiet sections of songs are absolutely clean without any noise, but as I mentioned once playback is stopped hum is there. In other words if on DAC green led is on everything is fine but once led is off noise is there.

Would it be possibly keep DAC turned on all the time even if playback is stopped or paused ? Some config/tweak ?

I tested it as well with USB DAC Fiio E10k and this works fine both when playing same as when not playing.

Thanks
Stepan

[hondagx35]

Hi Stepan,

did you try to update the kernel?
post18311.html#p18311

Frank

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[hondagx35]

Hi Stepan,

please try to play with the "Auto Mute" settings in alsamixer.


Frank

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good idea,
will try it today after work
and let you know.

thanks
Stepan

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I need to say, it doesn't help me. still when dac is not in use - stopped/paused after few seconds green light turns off and hum is there. It's same level as when cables to power amp are not conected to any player and act as "antena". btw I'm using dac with dual linear power source to be sure on this. Sure I test it with single power source as well. Both pi+hifiberry and power amp are in class II so there is no way for ground loops via PE wires.
Any idea?
for me would be enought to keep DAC on from boot to shutdown.
Some pareneters must control it...
Thanks
Stepan

[hondagx35]