The Sonos Play:5 does not have Bluetooth.  You could use a Bluetooth receiver in the Play;5s line in socket.  Or you could wire it as you suggest.  You would need a pre-amp, either built-in or standalone, so as to deliver a line-level signal to the P:5.

hi, thank you …… my mistake - pre-amp it is 

Whilst i have you John B….. Im looking for leads from the Pre amp to the solos Play 5 (2rca - 3.5mm). Its very confusing (as there are 100’s of them). How much difference do they really make 

Im looking at either QED or Audio quest EVERGREEN

Can you suggest anything 

Thank s 

I don’t really feel I know a huge amount about cables.  My only advice would be not to buy anything really expensive.  Cables are probably the area of HiFi equipment where the most money is wasted on products that give no audible improvement over much cheaper examples.

£8 - 12 should be plenty to get as good a result as you can hear..  It will depend a bit on the length.