There is a switch on the back label phono or Line. Make sure it is set to Line.
Then cord from phono to back of play:5
I assume you know how to play to line in (in the Browse section - very bottom option Line In and select your play 5 as the line in source (note you can also go into settings...room...chose the Play:5 room....line in tab...set it to autoplay to Play:5 so that any time you play from phono the speaker automatically switches to line in.
Respect the Queue (2)Move (3)Beam (1) Era100 (2)ARC (1)SonosOne (1)Playbar (4)Play5 (4)Play1 (3)Play3 (1)Port (2)Connect (1) Roam (2) Ace (1)Connect:Amp (4)Sonos Amp (1)Sub + (9) Echo + Smartthings; (2)Play)