USB DAC not recognized

JEffnot

Hi there, I wanted to connect my Headphone to my USB DAC with my Xiaomi Mi A2. DAC is not recognized by UT. Are external devices not supported?

arubislander

@jeffnot UT uses the same (build of the) kernel that Android on your device came with. This is to ensure all the on board peripherals have a chance of working. Often these kernels do not include support for external audio devices over USB.
But if the kernel and hardware support it, in principle it should 'just work''

JEffnot

@arubislander thx for your fast reply. On my Android I have to activate OTG to get the DAC working. Is there a similar way on UT?

JEffnot

I can find my DAC with "aplay -l"

And I can load my DAC with "pactl load-module module-alsa-sink device=hw:2"

Where 2 is the index of my USB DAC.

Now I got Sound!

How can i make this permanent, or maybe hotplug?

here_is_mike

Hey I tried the following:

make / writable.

check Vendor ID and Product ID with after you have plugged in the USB DAC :

dmesg | grep Vendor

for me
=>
"New USB device found, idVendor=05ac, idProduct=110a, bcdDevice=26.50"
(it is a: Apple, Inc. USB-C to 3.5mm Headphone Jack Adapter)
(for another product with another Vendor and Product ID icould also get another DAC work)

in cd /etc/udev/rules.d create:

# USB-DAC plug in
ATTRS{idVendor}=="05ac", ATTRS{idProduct}=="110a", ACTION=="add", RUN+="/usr/local/bin/load_dac_module.sh"

# USB-DAC unplug
ATTRS{idVendor}=="05ac", ATTRS{idProduct}=="110a", ACTION=="remove", RUN+="/usr/local/bin/unload_dac_module.sh"

reload udev rules:

sudo systemctl daemon-reload

sudo udevadm trigger

check aplay -l
for me:
=>
card 1 and Device 0

in /usr/local/bin/ create the scripts:
1.
/usr/local/bin/load_dac_module.sh

#!/bin/bash
sleep 1
sudo -u phablet pactl --server "unix:/run/user/32011/pulse/native" load-module module-alsa-sink device=hw:1,0

/usr/local/bin/unload_dac_module.sh

#!/bin/bash

# search for loaded module


sleep 1
USER="phablet"
#USERID from phablet= "32011
PULSE_SERVER="unix:/run/user/32011/pulse/native"

MODULE_ID=$(sudo -u $USER pactl --server "$PULSE_SERVER" list short modules | grep module-alsa-sink | awk '{print $1}'   )

# unload PulseAudio-Module , if it was loaded before
if [ -n "$MODULE_ID" ]; then
#    pactl unload-module $MODULE_ID
sleep 1
sudo -u phablet pactl --server "unix:/run/user/32011/pulse/native" unload-module $MODULE_ID
fi

make the files writable:

sudo chmod +x /usr/local/bin/load_dac_module.sh
sudo chmod +x /usr/local/bin/unload_dac_module.sh

unplug USB DAC
reboot
(if the USB DAC was plugged at boot it seem that the DAC does not work than.)
on a FP4 it took nearly 4 sec till the sound comes from the DAC

Could somebody test and verify it?

PS:
this helped me:
https://wiki.archlinux.org/title/PulseAudio/Examples#Automatically_switch_audio_to_HDMI