As long as it is sending nothing higher than a Dolby Digital codec, you should be fine. 

Analog Audio Output

1 x Analog RCA Line output,
1 x Digital optical (SPDIF) output,
1 x Digital Coaxial output,
up to 384kHz/32-bit

1 x Analog RCA Line output,
1 x Digital optical (SPDIF) output,
1 x Digital Coaxial output,
up to 768kHz/32-bit
DSD512

Is this OK?

I don’t think I’ve ever seen Sonos publish the SPDIF requirements, which I assume means all TVs send the same thing. Depending on what ‘up to’ means (do you choose?) I think you’re fine, as I said. If I’m wrong, someone will provide you better data. 

It’s not common to connect a DAC directly to a PLAYBAR, they’re normally connected directly to a TV set. 

What your specs don’t cover is what codec the output is in. Just frequency and bit rate. 

OK I will use a converter to be safe

Honestly, I wouldn’t spend that money until I had proven it didn’t work. 

You don’t need a converter. Just wire the WiiM to the Playbar and constrain the WiiM’s optical output to 44.1kHz and 16 bits. It might work okay at 24 bits; try it. 

Hello Ratty

Thanks

Will have a look at it when it arrives.

I feel obliged to ask: what are you planning to stream through the WiiM that the Playbar can’t manage itself? It’s not as if the Playbar can handle the high-res content the WiiM is capable of outputting. 

Just Spotify or Tidal.

I am not very knowledgeable about these things and just wanted to get better sound. 

:(

BTW, my Sosnos system has the 1's, playbar n a Sub. I thought it would benefit from a Wiim.

:(

Sonos supports Spotify and Tidal. Either using the native apps or the Sonos app.

At best your WiiM through the Playbar is likely to sound no different, unless you feel the need to tinker with the WiiM’s equalizer (PEQ/GEQ). 

The WiiM does of course offer additional input options, such as DLNA, Airplay2, Chromecast, Bluetooth, etc.

Thank you Ratty for all your help. 

Guess I just made a frivolous purchase or its time to upgrade my sound system! 

:)