When you have an Arcana, the ATV4K will be plugged into the Arcana then one cable goes to the Arc for audio and one cable goes to the TV “switch” you are talking about for video. It will work. 

Gotit on direct connect ATV.

I should have mentioned I have 3 devices plugging into the Samsung proprietary switch. Not just an ATV, that’s why I need to know if the Atmos passes thru the switch.

Can you post a photo of that Samsung switch? How is it connected to the TV?

@GuitarSuperstar 

Here is a photo of front and back of the Samsung proprietery HDMI switch.  

• Inputs are AppleTV, XBox, Nintendo Switch and ATT Streaming Box (Osprey).  
• Output is to the Samsung JU7100 (2015).

 

The One Connect Box for a Samsung, I think, is not a “proprietary HDMI switch”, but contains all technical parts for the TV (tuner etc.), that are normally built into a TV. The part of the TV you look at is only a monitor without it.

The answer to the question if will pass through Atmos can only be answered by other people woning this TV. I suspect not because the TV is quite old. It also does not have eARC, so full Atmos is out of the question.

I expect you need a real HDMI switch and connect just the HDMI-ARC on the One Connect Box to the Arcana.

Please define ‘full Atmos’. 

Atmos can be carried across ARC, in the codec of Dolby Digital Plus. But there are two ‘versions’ of Atmos, and the other, with additional channel information encoded in it, does indeed require eARC.

I absolutely concur with his statement that the device under discussion is not an HDMI switch, but the ‘tuner’ for that particular TV. 

@106rallye I expect you need a real HDMI switch and connect just the HDMI-ARC on the One Connect Box to the Arcana.

Can you help me with that a bit more?  Are you saying..

OUTPUT: AppleTV + Xbox + Nintendo + ATT Box to INPUT: <NEW> HDMI Switch

OUTPUT: NEW HDMI Switch to INPUT: Arcana

OUTPUT: Arcana ARC to INPUT: Samsung One Connect Box

OUTPUT: Samsung One Connect Box to INPUT TV using proprietery Samsung cable.

OUTPUT: Arcana e-ERC to INPUT: Sonos Arc Speaker

And, do you have a recommendation for the HDMI switch to get?

Thanks!

If you have more than one device that you want to get best possible audio from, then they need to go through the Arcana before they reach the TV connection box. Devices connected to the TV box directly will not have the sound improved by the Arcana. 
The connections above are correct. 
A lot of Arcana have success with the Roofull switch from Amazon. 
HDfury also recommends cablematters kabeldirect or zeskit cables, 6-12 feet long. Not just the specs of the cable is important, the quality is very important. 

I've seen uncompressed Atmos described as “full Atmos", as opposed to compressed Atmos in the codec of DD+.

Ah, have never seen that...and never looked, either. 

Mildly concerned that people who are not familiar with the term (like me) think you mean ‘no Atmos at all’.  But then I tend to make little distinction between the two in my posts, since the Arc is a soundbar, and not a full fledged multi component amplifier. I don’t think that there is anything in ‘full Atmos’ that would change the playback in the Arc, since I think (I keep using that word!) that the channels used by the Arc’s speakers exist in both versions of Atmos. But I’m more than willing to be educated there, too… ;)

@Airgetlam I have compared TrueHD Atmos and DD+ Atmos in the Sonos Arc. I find that the comparison is like FM to AM radio. Although the gap between the two is much much smaller than that between AM and FM. TrueHD Atmos has more precision and more clarity. Not huge difference, but it is there.

Interesting. I don’t hear the difference at all in my local environment. 

The difference between the two is that compressed Atmos cab be transmitted over Arc, so does not need eARC - if you would only use the apps on your TV (and the TV gives out DD+ to the Arc), the Arcana could be superfluous. I cannot comment on quality differences as I own no Atmos caompatible speaker.