AV Receiver Only Supports Dolby Vision @ 24p

[Manifest]

Hi all, go easy i've not posted in years

I have recently got an Apple TV but am having a problem with Dolby Vision, I can run the menus and any content at 4K HDR 60hz without issue, literally no problems at all, Gemini Man for example.

As soon as I switch on Dolby Vision from the settings menu at 25hz, 30hz, 50hz or 60hz my screen goes all purple and pink, however if I set this to 24p (23.etc) then Dolby Vision works. I have backed this up by going onto Netflix and loading up The Crown with his 25 content, the TV goes pink and purple, watch Stranger Things however and this runs fine, because this is 24p.

I have an LG B8 OLED from a few years ago and the inbuilt Netflix app plays any Dolby Vision content at any refresh rate, so the issue is somewhere else.

Plugging the Apple TV directly into the TV Dolby Vision works at all rates without issue, I have tried multiple cables and essentially isolated the issue to the AV receiver, when ever this is in the loop the issue is there. Simple answer buy another one but I need to understand why an AV Receiver that can do 4K 60 HDR10 can't do 4K 60 Dolby Vision, well in fact it can ONLY do 24p Dolby Vision, it won't even do 25 without the screen going purple.

Its not the most amazing amp in the world and to be honest probably pre dates DV, but it claims to simply passthrough content so where is the bottle neck?

It is a Pioneer VSX-531 which is spec'd as having 'UltraHD Pass-through with HDCP 2.2 (4K/60p/4:4:4) HDR Support.

Sure I can just get a new amp but I would like to understand why this isn't working?

Any help would be great.

 

[peahead]

Maybe it's a limitation of the chipset used in the amp that it can't do 60hz, i remember my old 2016 LG C6 OLED could only do DV 24hz because the chipset was not capable of it.

So just keep the Apple Tv boxed connected directly to the B8 OLED and use the HDMI ARC function to get the audio to the Pioneer amp.

 

[Manifest]

Maybe it's a limitation of the chipset used in the amp that it can't do 60hz, i remember my old 2016 LG C6 OLED could only do DV 24hz because the chipset was not capable of it.

So just keep the Apple Tv boxed connected directly to the B8 OLED and use the HDMI ARC function to get the audio to the Pioneer amp.

Yep I think you’re right, I just figured a ‘pass thru’ meant that the amp didn’t get involved but of course it must be travelling through some hardware in there.

Crazy that it will do 24p and not 25, literally just over 1hz difference.

Yeah I’m considering HDMI ARC or optical cable back to the amp for the Apple TV now, it just needs to be wife proof. At the moment there is a PS5, STB and ATV connected to the amp which connects to the TV, quite simple so I want to avoid adding in additional remotes! Anyway that’s my problem to solve but thanks for the inputs, I wasn’t going mad after all.

 

[barmyllama]

You may as well use ARC, since all the streaming services only output Dolby Digital audio at best anyway, no lossless formats, so you don't loose anything in terms of audio fidelity whether you use passthrough or ARC.

 

[Manifest]

I tried ARC out and it just wasn’t playing ball, it also adds in a extra cable to the TV.

I use Apple TV and infuse a lot to watch some local content as well as the steaming giants so I’d rather not use ARC, besides it became overly complicated with my existing setup, ok well more complex than it was before.

In the end I have found a mild upgrade to a Yamaha receiver that will do HLG and DV, it specifically says it’s supports DV so I hope this means it will support more than 24p also as that would be kinda gutting if not!