I haven’t tried this but I’m not aware of any reason why it should not work.
Yes, DD and DTS core (5.1) definitely. Some users can get DD+ through S/PDIF so you may also get DTS ES but it depends on the receiver.
@Chillbo knows the best settings for every situation.
Edit: Just tried the options for S/PDIF. You need channels: 2.0, Best Match, AC3 transcode on, AC3 and DTS passthrough on, EAC3 and DTS-HD passthrough off. I don’t get DD+ through S/PDIF but I do get DTS ES (6.1) and DTS 96/24 with these settings, it seems. YMMV.
…is perfect for S/PDIF. DD+ over S/PDIF can technically work, but your AVR must be able to handle 192kHz via Toslink for it to work. And it has to be able to handle DD+ itself obviously. You’re saying that your AVR can handle 4K, but not HDR. So, DD+ over S/PDIF might even work, considering the age of your AVR. But consult the AVR’s manual to see which samplerates are supported via Toslink or just test with the Vero 4k. (DTS ES (Discrete)/DTS 96/24/Dolby EX should always work via S/PDIF as they’re extensions of non-HD passthrough formats made for the DVD era, ergo for S/PDIF)
This was actually something we recommended to a user on the forum who had an HDMI AVR that couldn’t handle 4K. He wanted to get the HD audio via HDMI, but also 4K to his TV. Some high-end UHD BD players have dual HDMI-out to do this, but obviously the Vero 4k hasn’t. The user chose a HDFury AVR Key (HDMI audio passthrough LG B6P? - #10 by fragment), but I’m not sure whether it solved it for him. Maybe PM him and ask him about his experience…
If you have a good AVR that you want to keep and that can handle all audio formats that require HDMI, I’d look into such a splitter solution (rather than buying a new one or falling back to S/PDIF). It will probably give you the best of both worlds - 4K HDR and HD audio. Nobody of us has tested such a setup though, so you’d have to pretty much find out yourself how it’s done and whether it’ll work as expected.
It was mid-range when I bought it: Sony STR-DN850. That HDMI switch would be a risk and it would rather by a new AVR (trying to sell the current one on Gumtree actually).
I bought a new SPDIF cable and tried the settings above and others. It can’t get it to work. I also tried disabling HDMI audio from Settings/System and I restarted.
With HDMI audio disabled it always says No Stream Detected on the AVR.
The AV receiver input is TV (and always TV, since I don’t use it with any other inputs).
There’s a complicating factor I forgot earlier: The AVR has two SPDIF sockets. One is labelled TV and the other one is SAT/CATV. Obviously the SPDIF cable is in the TV one. (I tried the other one and changing input to SAT/CATV too.)
In the AVR settings Optical 1 is permanently enabled as an input for TV.
The reason I’m looking to do this is that audio is always AC3, or PCM 2.0 for everything else. I discovered that I can listen to DTS if I change a setting on my TV to DTS manually. It’s awkward to switch back and forth so I still want to get audio over SPDIF working…