Failed to open "ALSA Default" (alsa); Failed to open ALSA device "_audioout": No such

[Relocated2007]

Your Rotel A12 states..
PC-USB USB Audio Class 1.0
(up to 96kHz 24bit)
USB Audio Class 2.0
(up to 192kHz 24bit)*
*Driver installation required

From the MoOde log...

Code:

ALSA cards: (0:b1 | 1:Headphones | 2:empty | 3:empty
20211218 021936 worker: MPD config: (2:Rotel USB Audio 2.0 | mixerSadRotel USB Audio 2.0 ) | card:2)
20211218 021936 worker: WARNING: No device found at MPD configured card 2

 Rotel may not provide Linux support for  USB2.0  if they are specifying a driver required (Windows)
You could email Rotel and ask about Linux support. (Though looking via Google it seems that Linux shouldn't need any thing special for USB 2 and Rotel)

 One thing to check...what USB ports are you using from your Pi4 to the Rotel ?  USB2 or USB3 ? (Suspect it might be USB3)  swap to the other (USB2) and reboot.

Tim or Kent may be along with more insights once their side of the world wakes up :-)

I used USB 2.0 ports as USB3.0 are for SSd as they are fast.