Hi.  To add the turntable you really need a Sonos speaker with a line in.  The cheapest option is a Port, but that is not the Port’s primary purpose and it is a lot of money just to get a line in.  I always think a Sonos Five is a better-value choice because you get a great speaker as well as a line in.

The Beam isn’t really designed to take a turntable.  To do it you would need an an analog-to-digital converter and an optical switch.  The switch is needed to allow you to choose the TV or turntable as a source.  You could play the music to the Play:1s by grouping them with the Beam.  It isn’t perfect, but much cheaper than buying a Five or a Port, if you need a Beam anyway..