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DAC2 HD + DSP add-on low volume

Austin

February 21, 2025 16:20

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Hello,

I have a DAC2 HD and I love it. It has worked flawlessly for me. I recently added the DSP add-on board to it and immediately noticed the volume output dropped significantly. After some troubleshooting, I discovered that since adding the DSP board, alsamixer lowers the DAC volume by 20db. HifiberryOS GUI shows volume sliders maxed for sources and system, but the DAC volume in alsamixer shows -20db.

It returns to normal once I increase the volume back up to 0. Anytime the pi is rebooted the DAC volume is lowered -20db in alsamixer and I need to go in and increase it.

Is this an intentional design decision or is this a bug of some kind? If it is a bug, is there a way I can have alsamixer keep the volume at 100 after reboot? Thank you.

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3 comments

• 0
  
  HiFiBerry team February 25, 2025 07:00

  Sounds like a bug that the volume of the DAC isn't set to full volume. As the volume control with the DSP is handled by teh DSP add-on, the volume of the DAC isn't changed.

• 0
  
  Arjan H. February 28, 2025 22:31

  Exactly the same thing happened to me when I added the DSP board to a DAC2 HD. I went hunting for the -20dB value and eventually managed to find it:

  /usr/share/alsa/init/default

  I changed the value for ENV{pvolume} as follows:

  ENV{pvolume}:="0dB"

  After this change the volume of the DAC is set to 100. I use an external speaker and I wanted the volume fixed. From what I gather the variable controls the volume for devices that have no volume set. Which may point to the actual problem, which I did not find nor fix. But this may work for you as it did for me.

• 0
  
  Austin March 02, 2025 21:12

  Hey nice find!

  I wrote a simple bash one-liner and set as a service to set the DAC volume to 100 but your method works better. I would rather set in the config. Thanks!