Raspberry 4 + Moode and Project Pre Box S2 Digital

[MoodeAD]

Good morning,
I have a Raspberry with Moode installed and connected to a Pro-ject Pre Box S2 Digital and Accu Box S2 power supply.
I tried to eliminate the 5V power supply via USB from the raspberry to power the preamp with only the Accu Box S2 (removed the red USB cable).
When starting Moode an error comes out:

Failed to Open "ALSA bDefaukt" (alsa);
Failed to open ALSA device
"_audioout":No such file or directory

Can you help me understand what is happening and how can I fix it?
If it is possible to fix.

Thank you

Daniele

[Tim Curtis]

If the device can also be powered by USB it prolly requires the power wire in the USB cable to be operational.

Good question for the manufacturer.

[MoodeAD]

In the DAC's manual, I can ready:

Mains power connection
The unit offers 2 possibilties:
1. USB input is not used: Connect the low voltage plug from the power supply to the micro-USB socket Power 
5V DC before connecting the power supply to the mains.
2. USB input is in use: Unit can be powered directly from computer via USB input. In this case is highly 
recommended to disconnect Power 5V DC cable from the unit - power disturbances from two power supplies
could affect sound performance.

If I use USB input, I can't use a dedicated Project linear Power supply, and only via USB I can ready DSD file or PCM in High resolutiin.