When used as surrounds, the line-in feature on the Era 100s is disabled. You either need to remove the Era 100s as surrounds to re-enable the line-in feature or add another Sonos device with line-in. If the turntable is in the same room as your Arc setup, consider adding a Sonos Port or used Connect (Gen 2). If the turntable is compatible with Bluetooth, you could add a Roam SL and share the Bluetooth audio to the Arc.
Thank you for response, but it’s sad.
Yes my turntable (not Bluetooth model) is in the same room, if I understand well, with Sonos Port I can connect my turntable to the Sonos Surround ?
Or maybe, I connect the turntable to the TV…