Please recommend me a solution to this problem

When you want to use your headphones, turn off CEC on the TV set. 

This is an issue with the CEC standard, which only allows one ‘sink’ for audio. It isn’t unique to Sonos, unfortunately. 

When you want to use your headphones, turn off CEC on the TV set. 

Thank you for your reply.

I do not use CEC and it is permanently OFF on the TV.  I think it’s a Sony TV thing, you cannot have both eARC and digital output at the same time.  Maybe I’m wrong, if so please let me know.

I need a digital output somehow, the question is how?

Ah. It’s a CEC thing, not unique to Sony. When you turn off CEC, it should energize the optical output, to my knowledge, since it no longer has any knowledge about what is connected via eARC. The challenge would be to get both operating at the same time. 

You could probably get just a standard HDMI switch that has an optical out on it to connect to the headphone. However, I’m not 100% sure whether any of those switches pass through a full Dolby Atmos signal, or just a Dolby Digital signal to the TV that would be reflected back to the Sonos on HDMI eARC. 

I don’t think I can get a standard HDMI switch as the Beam requires eARC/ARC to work.  It will not work with a standard HDMI Connection.  Well, that is what I think, maybe I’m wrong.

One could try inserting a CEC eliminator into the HDMI-ARC path. By the way, CEC is on pin 13 of the HDMI cable. It’s not easy, but you could remove pin 13 — from a cable that you don’t like.

So CEC is causing this, I would not have guessed that.  Surely there must be a way of turning making the Sony TV think CEC is disabled.  Obviously turning if OFF in the settings is not enough.

I don’t have a SONY set to prove this, but we are suspicious. Some TV’s require that CEC be enabled before they’ll pass HDMI-ARC audio, but they don’t seem to freak out if no CEC commands arrive. If you block CEC, Volume control of BEAM and power control of the TV will not be as integrated.

As I understand it you cannot use e(ARC) without having CEC (Bravia Link) on. As stated above the TV would not know the Beam is there without CEC, so the Beam would not work.

OK fine I understand that now.  But my original question was about adding a device that would either negate turning ON CEC on the TV or giving me a digital output (not via the TV of course).

Both would need to enable me to not lose any quality of video nor audio.

Suggestions greatly appreciated.

TIA

Try inserting a CEC blocker between ARC and TV.