You could connect a Bluetooth receiver to one of the Sonos devices that have an analog input?

Hi Bruce

Thanks for your swift response!

 I’ve got a Beam only, so that means one HDMI input and a network input.

Am I going to need another box or cable to connect the Beam to a Bluetooth turntable?

Yes, I’m afraid so. Other than the Move, Sonos doesn’t deal with bluetooth, and even the Move, when connected via Bluetooth, it’s not connected to the rest of the Sonos system. My recommendation is usually a PLAY:5, so that then you have another speaker to use, but you could use any of the Sonos devices that have an analog input, the PLAY:5, the Amp, the Port. None of them are particularly inexpensive, depending on your definition. 

I think I’ll just get another Sony Bluetooth speaker to accompany my old one and use that as a separate system for the turntable.

I’m not going to buy another Sonos product - apart from those Symfonisk separates from Ikea as rear effect speakers! 
Thanks again!

Sonos makes a speaker that can be switched between bluetooth use, and wifi use, called the Move. I’m told it’s a great bluetooth speaker.