I've tried getting a Raspberry Pi and following some guides to turn it into an internet radio broadcaster that I can then pipe into Sonos, but the audio quality was always atrocious and the case that came with my Pi kit has a fan that is super loud.
I could get a Sonos Port for 700 AUD and do it the official way... but my record player is only like 300 AUD so it doesn't seem worth it. Here's hoping I can find a cheap used one.
Sonos needs to add an analog audio in port on more of their devices.
I agree that it wouldn't take much to do so and it would increase its accessibility, but I just don't think they have an appetite to do that.
The Sonos port device which they have had to allow you to physically connect devices has always been atrociously expensive. To think that I could buy two of their rear Sonos speakers and still have money left over be cheaper than the port is just silly.
https://www.sonos.com/en-au/shop/five
The Port and Amp are definitely aimed at the very high end consumer who wants a whole wireless system in their house and wants to connect to non Sonos speakers.