If you connect to a TV using ARC, what is the best ARC/eARC converter to Dolby Atmos sound from Sonos home theater?

There is the HD Fury Arcana, the Feintech VAX04101k, and the OREI HDA-935.

The Arcana is the most popular option and seems to be the most reliable. 

I can only speak to the HD Fury Arcana, as I have not tried the other two options mentioned above. My honest thoughts, sure it does the job, but it’s way overpriced. Like you, BurgessKoch, I was among the “lucky” consumers to purchase the 2018/2019 last model year make of the Samsung with ARC, mine the 75” Samsung QLED with ARC. After trying to hookup my Sonos Arc and Sonos One surrounds with subwoofer, I was not getting Dolby Atmos sound. If I had only waited for the TV with eARC a few months later, my TV, Sonos and Hue Sync Box nightmare of the past 5 years would never have happened. My advice, get a TV with eARC if you want Atmos and Dolby Vision quality all running smoothly. The HD Fury Arcana, while expensive, does the job (for the most part) of converting ARC signal to eARC. But when I received it in the mail, I quickly found myself looking up what all the 20+ settings really meant and always unsure if I had the right combination. I certainly learned a lot about picture quality and visual specs, and then I discovered that the HD Fury Arcana was not enough for my system (75 Samsung QLED ARC / Hue Sync Box / Sonos Arc-ethernet / Apple TV-ethernet). Based on what I read, I needed to get another HD Fury piece of equipment, the VERTEX or DIVA for additional scaling, at a price point even higher than the HD Fury Arcana. I could not justify an additional $500 investment in a system that will always have a flaw since the level 1 base HDMI output from the TV is ARC. I was able to get through a few more years with the setup, needing to occasionally reset all the connections after one of the systems had an updated. Again, get a TV with eARC in the back. I haven’t looked into the Arcana 2 or VRROOM but seems like for a similar setup, I would need to VRROOM. Definitely do your research.

I moved 6 months ago and bought a new 65” LG B2 QLED with eARC for my bedroom during Black Friday, and what a world of difference and a lot less headache when it came to setup.  I will say most of the frustration now really do stem from the Philips Hue Sync Box. Why I don’t take it out of my system? Because of the money and time over several years of getting enough Hue light bulbs and fixtures to light up my street block in Brooklyn. I digress.

You are probably dining this because you are using your Apple TV for Atmos? Before going the converter route, that will ad complexity to your set up, have you tried the settings that on your Apple TV that will make it emit DD+ with compressed Atmos? I seem to remember this is also possible.

I own both the HDFury Arcana and the Orei HDA-935 both will get you Dolby Atmos, I prefer the Orei, but if getting some form of Dolby Vision (LLDV) on a Samsung TV is important to you then the Arcana is the route to go down.