If you are connecting to Sonos, you are going to need a pre-amp, either built into the turntable or external.  There’s no way around it.  As to how to connect, anything with Amp in the name is overkill, unless you wish to power passive speakers.  The least expensive solution is an Era 100 with the Line-In dongle accessory. A Port, Five or Era 300 will also work. 

Thanks, I do realize I need a pre-amp.  If I connect the pre-amp to a Sonos Port, can I listen to my turntable through my Sonos One SL speakers, or only to external speakers?  My objective is to listen through the Sonos speakers, not external speakers.  

Anything wired to a Line-In can be played anywhere on the system. 

@Joe_Mamma --Reiterating what @ratty said, plug your turntable /preamp into the Port line-in. You can then use the app to route the music to almost any speaker on your system. The exception is if your Ones are set up as surrounds. I haven't found a way to temporarily un-group my rear Ones from the Arc just for playing music. As @jgatie  stated you can also use the direct line-in to the ERA series or Five, but that puts another speaker in room where you may already have some.   Save some $$ and look for a used or open box Port. It's small and designed for exactly what you are trying to do. 

@MrZack -- The Port sounds like my best option - however my Ones are set up as surrounds.  

Does anyone have a work-around for the problem described by MrZack?

It’s not a practical project. You would need to remove ONE’s from the surround room in order to play them standalone, then you would need to re-add for surround. Plus, Trueplay does not retain any settings. This will become an unwelcome chore after the first few transitions.

Based on current feedback, sounds like with my current system (again, Playbar, Two One SL’s, Sub), there are no good options for connecting a turntable and playing it through my One’s?  

One option would be to connect the turntable to the Playbar, and play through the entire set. You’d need an analog-digital converter (cheap) and an optical switch (also cheap). The turntable would play through the “TV” input. 

@ratty, wow that sounds too easy - thanks!

But you'd have to switch the optical connection each time you want to listen to your turntable. In my experience optical connections need care when plugging and unplugging - I'd not swap plugs too often with optical. And this also will not solve the point of the turntable being played over both Playbar and surrounds.

Of course, which is why I included an optical source switch on the shopping list. 

106rallye wrote:

 And this also will not solve the point of the turntable being played over both Playbar and surrounds.

My understanding was that with the a/d converter and optical switch, the turntable would in fact play over both the Playbar and surrounds - please explain your comment further.  Would it play over just the Playbar?

106rallye wrote:

And this also will not solve the point of the turntable being played over both Playbar and surrounds.

Please explain further, my understanding was that with the a/d converter and optical switch, the turntable would in fact play over the Playbar and surrounds - will it play over the Playbar only?

Sorry, I missed the recommendation for a switch.

I read read in your question you wanted to play the turntable only through the One’s, not also through the Playbar. As mentioned this is not easily done. Playing from both Playbar and surrounds is possible. The surrounds must be set to “Full” in the settings. When the surrounds are set to “Ambient” you will only hear the music faintly.

@106rallye -- you are correct, I did originally state a desire to play through the One’s but should have said the One’s and the Playbar.  Understood about the surround settings.  Thanks.