Would HDMI Arc to Optical converter work?

I see no mention of ARC support, so plugging it into the ARC port on your TV isn’t going to do anything.

This device is designed to plug into a source device (eg cable box, Xbox), and extract the optical signal from that.

What kind of TV is new enough to have an ARC port, and yet old enough to not have optical?

There are similar audio HDMI adapters/switches which can also be configured to extract audio originating from the TV on the HDMI-ARC connection. 

Found this bit as odd, too: Note:Our product don’t support Dobly Digital plus and CEC function)

It does have an ARC button, and states this, though: Support HDMI ARC (Audio Return Channel)

But I do share the views of both controlav and ratty, this is unlikely to be a satisfactory device. 

My mistake. I see the linked converter does sport an ARC selector. I went by the product title and didn’t dig deeper.

DD+ isn’t compatible with S/PDIF.

Maybe the adapter isn’t transparent for CEC between its input and output. This may not be an issue. 

It’s not well written, to be sure. It should be calling out other formats that it doesn’t support due to the restrictions of S/PDIF, too. 

I’m more conversant with the ‘switch’ type of these kinds of devices, which would allow more than one HDMI input. 

Thank you all for your answers.

controlav: My TV is a 2013 Panasonic Plasma. It has optical out. But the optical out port does not passthrough surround sound. Just stereo.

Airgetlam: Maybe it supports Dolby surround but does not support newer formats like Dolby Digital + etc.

Unless I receive some kind of surround sound (doesn’t matter if its old format) I’ll be happy.

What are my chances with this product guys?

So you’d go HDMI-ARC from TV through converter to optical to Playbar? In the hope the TV passes through DD 5.1 to the converter and so to optical and Playbar? It may work. For under 25 dollars (and Amazon’s return policy?) you could try it.

Frankly, I’m somewhat surprised that a 2013 TV has ARC of any type at all, but won’t pass Dolby Digital out an optical port. 

It would be helpful to know at least the make and model number of your TV, if you can’t provide a link to the online manual for it. 
 

However, I think if you insert this device between the source and your TV, it would pull off a Dolby Digital signal if it exists in the HDMI stream, and send that out via optical to the PLAYBAR, and pass the video stream to the TV set. You would not get any audio from ‘smart apps’ that exist on the TV itself, however. 

106rallye: I’m thinking the exact setup you mentioned. I think I’ll try my luck.

Airgetlam: The model is Panasonic The TX-P65ST50E. Unfortunately my Playbar does not receive any surround sound (checked it several times through the app) and its a real bummer! At that time I never thought of checking it out...

Looking on page 110 of the manual for this device, it purports to support PCM, Dolby Digital, DTS, and Fiber Optic. Not sure what that last one is there for, Fiber Optic is not a codec. 
 

I would question the source device that you’re using is actually sending a Dolby Digital signal to the TV to pass through to the Sonos. It should not be sending a DTS or Dolby Digital Plus signal, just Dolby Digital. It might be worth double checking that source device’s audio output settings before spending any money at all, it’s entirely possible that you just need to adjust settings. 
 

There is no indication in this manual that any of the HDMI connections are ARC capable.