Raspberry Pi4 doesn't find DAC after restart

MyVolumio MyVolumio Help and Support
1

Hi all,
I’m using the latest volumio version (3.785) on a raspberry pi 4. I have an audioquest Beetle connected via USB as a DAC. During the setup, the DAC was automatically found as an audio output source and worked just fine.

The problem I’m having now is that after a reboot, the DAC is not found and only headphones and HDMI is in the list of options. When I disconnect the USB cable of the DAC and plug it back in, I can select it again in the list.

Anyone has an idea what could go wrong here?

Thanks a lot on advance!

2

This is a long-standing issue with the Raspberry Pi 4B’s USB subsystem where some USB devices are not properly reinitialized after a reboot. The problem is related to how the Pi’s USB controller handles power and device enumeration on startup.

Possible Workarounds:

  1. Use a USB Hub – Some users have found that connecting the DAC through a powered USB hub helps retain recognition after reboot.

  2. Enable USB quirks – Add the following line to /boot/userconfig.txt to force reinitialization:

    dwc_otg.lpm_enable=0

  3. Reinitialize the DAC manually – Create a script to reset the USB bus after boot using:

    echo '1-1' | sudo tee /sys/bus/usb/drivers/usb/unbind
sleep 1
echo '1-1' | sudo tee /sys/bus/usb/drivers/usb/bind

    You can automate this by adding it to /etc/rc.local before exit 0.

  4. Use a udev rule – Create a rule in /etc/udev/rules.d/99-usb-dac.rules:

    ACTION=="add", ATTRS{idVendor}=="XXXX", ATTRS{idProduct}=="YYYY", RUN+="/bin/sh -c 'sleep 2; /usr/bin/volumio upnp-rescan'"

    Replace XXXX and YYYY with your DAC’s vendor and product ID (lsusb will show this).

Unfortunately, this is a known quirk with the Pi 4’s USB behaviour, and there isn’t an official fix from the Raspberry Pi and the only properly working solution is power drain (full power off) instead of reboot.

Kind Regards,

3

Hi! Thanks a lot for the reply. I tried all the mentioned workarounds (except the USB hub) but unfortunately it did not work.

You mentioned that the issue should be solved with a power drain (full power off). Unfortunately, this does also not work in my case. I power down the raspberry pi with the Volumio interface and disconnect the pi from the power supply. After starting the pi again, the DAC is not in the list of audio output options. Disconnecting and reconnecting the DAC to USB establishes the connection again.

Any idea if there is a solution for that? Or should I just go for a raspberry pi3b?

Thanks and best regards!