Seems like I’m having a similar issue on Odroid N2. Since the update to DietPi 9.0, the “USB-DAC” card is not detected anymore. Going back to 8.25.2 is a workround to address the problem at the moment.
Selecting the soundcard in dietpi-config results in this.
[ INFO ] DietPi-Set_hardware | Applying new sound card settings...
[ OK ] DietPi-Set_hardware | Setting in /boot/dietpi.txt adjusted: CONFIG_SOUNDCARD=usb-dac
[FAILED] DietPi-Set_hardware | Unable to find any USB DAC on your system, reverting to "none"...
[ OK ] DietPi-Set_hardware | Setting in /boot/dietpi.txt adjusted: CONFIG_SOUNDCARD=none
[FAILED] soundcard usb-dac | Exited with error
That’s the aplay -l output
Karte 0: AU670AU671 [Yamaha A-U670/A-U671], Gerät 0: USB Audio [USB Audio]
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0
Karte 1: ODROIDN2 [ODROID-N2], Gerät 0: fe.dai-link-0 (*) []
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0
Karte 1: ODROIDN2 [ODROID-N2], Gerät 1: fe.dai-link-1 (*) []
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0
Karte 1: ODROIDN2 [ODROID-N2], Gerät 2: fe.dai-link-2 (*) []
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0
And here the arecord -l output
Karte 1: ODROIDN2 [ODROID-N2], Gerät 3: fe.dai-link-3 (*) []
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0
Karte 1: ODROIDN2 [ODROID-N2], Gerät 4: fe.dai-link-4 (*) []
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0
Karte 1: ODROIDN2 [ODROID-N2], Gerät 5: fe.dai-link-5 (*) []
Sub-Geräte: 1/1
Sub-Gerät #0: subdevice #0