When set to uncompressed audio, the analog line-in on Sonos players (not the TV input on the home theater players) will convert incoming audio streams into 44.1/16 bit WAV. If you’re sending a higher bit rate into that input, it’ll go through the DAC (as all incoming signals are converted to digital so they can be sent across the network) and converted before played. 

As far as I know, Airplay streams in lossless ALAC 44.1/16 bit even if the source is a higher bitrate, Airplay will compress it to 44.1/16 bit before sending it over your network. 

What the hell happened?   Now Amazon says Sonos is not supported for HD, and it is Sonos that is blocking this.  
I know that “ultra” isn’t possible, but we can’t even stream CD quality now.
Amazon’s “ultra hd” playlists used to appear but now are gone.

 

I wonder if Quobuz is supported.

Is it just Amazon HD that is not supported or any Hi-Rez service?

Do you have a source?

That’s odd, as my Amazon Music HD service in the Sonos App is showing HD playlists here on my iPhone.

I can confirm as a Sonos representative that Amazon Music HD is still available on Sonos as a supported music service. I’m not sure what you heard from Amazon, perhaps there was a miscommunication with timbotwiddly and the person he spoke with.

Will this be part of the new release in June?

Is Amazon Music HD worth getting?

Just sighed up sounds great thank you Sonos And amazon for this

Now that S2 is released and Sonos Arc, will Sonos support the UHD/3D formats from Amazon Music HD?

not at the moment it is still 16bit 44.1khz cd quality  this may change in the future sonos does not release a schedule of when features will be added. let sonos know your interested in getting hi res streaming on sonos S2 products.  currently sonos can from a computer or nas play up to 24bit  44.1 to 48khz in flac or alac. but not streaming yet.