You can connect a turntable to the line-in on the Play 5 gen1. However the turntable will need a pre-amp either built-in or 3rd party outboard. In order to hear vinyl on the Play 3 you must group to the Play 5. If not you’ll need a Connect (discontinued) or a Port. All products mentioned are S1 compatible.

The line-in “input” on the Play:5 can be the source for the Play:3, even if the :5 is playing something different. 

Bonjour,
Merci pour votre retour et désolé pour ma réponse, mais je viens de rentrer de voyage.
Alors si je branche ma platine vinyle directement sur ma Play 5 avec une prise jack, cela fonctionne très bien !
Merci et meilleures salutations

The Play:3 and Play:5 are non usable now with the death of the S1 app/controller 

Moderator edit: Largely incorrect - S1 can still be used, and Play:3 is S2 compatible.