Amazon Music UHD digital format

[MabeHall]

It is my understanding Amazon Music uses FLAC at various resolutions. I see this on the WiiM app. But, my Denon receiver says the input signal is PCM (at the correct resolution). Is the WiiM coverting the Amazon signal or is the Denon? Using HEOS in the Denon, the Denon says the Amazon input signal is FLAC.

 

[ratty]

The WiiM decodes the FLAC stream then sends PCM to the Denon over S/PDIF.