Hi @Contrarian33, you’ve got two equally practical choices:

• Use the RCA line-outputs into the Era 100 via the Sonos Aux Line-In Adapter
  https://www.sonos.com/en-us/shop/sonos-line-in-adapter
• Use the Bluetooth capability of your turntable into the Era 100

The first choice is likely less frustration, the second choice you can try right now.

Thanks, @press250 ! But how do I connect the RCA cable into this in-line adapter? Im assuming I need an RCA female to 1/8 inch male adapter to go into the female end of the Sonos adapter?

Note that Line-In is disabled when a speaker is configured as a surround.

Make sure that the adapter is stereo

Correct, you would need that RCA to mini jack stereo adapter to get the signal in to the adapter that @press250 linked to. 

 I don’t think Bluetooth would allow grouping with other speakers.  RCA to 3.5mm male + Sonos adapter would be best and would probably sound best.

Hi @Contrarian33, you’ll need something like this stereo RCA-to-3.5mm cable ...

https://www.amazon.com/dp/B01D5H8JW0

Thanks, everyone -- super helpful!