Sonos Connect has very high jitter to be feeding to a DAC:
Synchro-Mesh can reduce this to 7psec, lower than ANY CD transport. You want Sonos to sound better than a CD player? The Synchro-Mesh can do this.
Apple Music Converter Mac is the tool for me to convert purchased iTunes music from M4P to MP3. Since all Apple music are encrypted with fairplay DRM protection, it can be played on Apple devices only. Fortunately, now you can use this DRM removal tool to remove DRM protection and convert music to MP3, WAV, FLAC, M4A, M4B, AAC, etc at faster speed without hampering the quality. After conversion, it will be much easier for you to play all Apple music on any devices freely.
Well, you can try Tunelf Audio Converter to convert iTunes music from a protected format to a common MP3 or other audio formats that are supported by Sonos. After that, you can easily transfer all these iTunes songs to Sonos for playing easily. I've used this tool for several months and it worked well. The output quality is almost the same as the original ones. Still quite happy with it.