As I was confused as others beginning with OSMC and DACs I would like to share my log and selection:
Some while ago I got an Kebidu 2022 Professional Usb Sound Card 6 Channel 5.1 Optical External Audio Card Converter Cm6206 Chipset For Desktop Tablet - Sound Cards - AliExpress (but from a different store). It work excellent with my RSX-1057 | Rotel by simply setting S/PDIF:
To learn more details I installed alsa-utils - Help and Support / Vero 4K / Vero 4K + - OSMC Forums
Got some guidance hwo to test in USB DAC Problem - Help and Support / Vero 4K / Vero 4K + - OSMC Forums.
Found an answer on ‘surround21’ in Osmc no sound from Audio Usb Pnp Sound device after upgrade to kodi 19 - Help and Support / Raspberry Pi - OSMC Forums
Here are my logs for reference:
osmc@osmc:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: ICUSBAUDIO7D [ICUSBAUDIO7D], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
====================== System Journal ===================
osmc@osmc:~$ journalctl | paste
Dec 17 19:34:39 osmc kernel: usb 1-1.4: new full-speed USB device number 3 using xhci_hcd
Dec 17 19:34:39 osmc kernel: usb 1-1.4: New USB device found, idVendor=0d8c, idProduct=0102, bcdDevice= 0.10
Dec 17 19:34:39 osmc kernel: usb 1-1.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
Dec 17 19:34:39 osmc kernel: usb 1-1.4: Product: USB Sound Device
Dec 17 19:34:39 osmc kernel: input: USB Sound Device as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.4/1-1.4:1.3/0003:0D8C:0102.0001/input/input0
Dec 17 19:34:39 osmc kernel: hid-generic 0003:0D8C:0102.0001: input,hidraw0: USB HID v1.00 Device [USB Sound Device ] on usb-0000:01:00.0-1.4/input3
Dec 17 19:34:39 osmc kernel: usb 1-1.4: current rate 30464 is different from the runtime rate 96000
Dec 17 19:34:39 osmc kernel: usb 1-1.4: Warning! Unlikely big volume range (=8065), cval->res is probably wrong.
Dec 17 19:34:39 osmc kernel: usb 1-1.4: [9] FU [Mic Playback Volume] ch = 2, val = -6144/1921/1
Dec 17 19:34:39 osmc kernel: usb 1-1.4: Warning! Unlikely big volume range (=8065), cval->res is probably wrong.
Dec 17 19:34:39 osmc kernel: usb 1-1.4: [11] FU [Line Playback Volume] ch = 2, val = -6144/1921/1
Dec 17 19:34:39 osmc kernel: usb 1-1.4: Warning! Unlikely big volume range (=6928), cval->res is probably wrong.
Dec 17 19:34:39 osmc kernel: usb 1-1.4: [8] FU [Mic Capture Volume] ch = 2, val = -4096/2832/1
Dec 17 19:34:39 osmc kernel: usb 1-1.4: Warning! Unlikely big volume range (=6928), cval->res is probably wrong.
Dec 17 19:34:39 osmc kernel: usb 1-1.4: [15] FU [Line Capture Volume] ch = 2, val = -4096/2832/1
Dec 17 19:34:39 osmc kernel: usb 1-1.4: Warning! Unlikely big volume range (=6928), cval->res is probably wrong.
Dec 17 19:34:39 osmc kernel: usb 1-1.4: [2] FU [PCM Capture Volume] ch = 2, val = -4096/2832/1
Dec 17 19:34:39 osmc kernel: usbcore: registered new interface driver snd-usb-audio
Dec 17 19:34:39 osmc systemd-udevd[3811]: event0: Process '/usr/bin/evrepeat -d 500 /dev/input/event0' failed with exit code 1.
Dec 17 19:34:39 osmc systemd[3756]: Reached target Sound Card.
====================== Kernel Message Log ===================
osmc@osmc:~$ dmesg
[13428.781620] usb 1-1.4: new full-speed USB device number 3 using xhci_hcd
[13428.908239] usb 1-1.4: New USB device found, idVendor=0d8c, idProduct=0102, bcdDevice= 0.10
[13428.908257] usb 1-1.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[13428.908266] usb 1-1.4: Product: USB Sound Device
[13428.916661] input: USB Sound Device as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.4/1-1.4:1.3/0003:0D8C:0102.0001/input/input0
[13428.974019] hid-generic 0003:0D8C:0102.0001: input,hidraw0: USB HID v1.00 Device [USB Sound Device ] on usb-0000:01:00.0-1.4/input3
[13429.062013] usb 1-1.4: current rate 30464 is different from the runtime rate 96000
[13429.080992] usb 1-1.4: Warning! Unlikely big volume range (=8065), cval->res is probably wrong.
[13429.081005] usb 1-1.4: [9] FU [Mic Playback Volume] ch = 2, val = -6144/1921/1
[13429.087009] usb 1-1.4: Warning! Unlikely big volume range (=8065), cval->res is probably wrong.
[13429.087023] usb 1-1.4: [11] FU [Line Playback Volume] ch = 2, val = -6144/1921/1
[13429.103629] usb 1-1.4: Warning! Unlikely big volume range (=6928), cval->res is probably wrong.
[13429.103643] usb 1-1.4: [8] FU [Mic Capture Volume] ch = 2, val = -4096/2832/1
[13429.111639] usb 1-1.4: Warning! Unlikely big volume range (=6928), cval->res is probably wrong.
[13429.111651] usb 1-1.4: [15] FU [Line Capture Volume] ch = 2, val = -4096/2832/1
[13429.119624] usb 1-1.4: Warning! Unlikely big volume range (=6928), cval->res is probably wrong.
[13429.119637] usb 1-1.4: [2] FU [PCM Capture Volume] ch = 2, val = -4096/2832/1
[13429.120162] usbcore: registered new interface driver snd-usb-audio