Originally Posted by jdsmoothie
Rather than suggesting things that Marantz may have already discussed with you, it would be helpful for you to list what has been suggested and what has already been tried.
Are you using HDMI.org "Premium" certified 4k/18gbps cables as is recommended? Have you tried setting the <4k Signal Format> setting to "Enhanced"?
I have tried several different high speed UHD HDR 18G HDMI cables. I have some from Costco (sapphire 4k + HDR I think), one that came with the Xbox One X, one that came with the Sony UHD player, the one that came with my movie player, and some from Monoprice. I really don't think it is a cable issue (see below).
The AV7705 is set to Enhanced Mode for the 4K signal. That is the only way to get Xbox to unlock HDR features.
What has already been tried.
1. Hooking sources directly to the TV and through the AV7705. Direct source connection to the TV results in correct signals. The same result with each of the above mentioned cables. For example, when connected directly to the TV, UHD bluray play playing a bluray movie plays on the TV at 4k/24hz. When connected through the AV7705 with identical settings, the movie plays at 4k/60hz regardless of the video settings on the AV7705 (conversion on or off, i/p scalling on or off).
2. Marantz had me turn on HDMI CEC which resulted in the AV7705 being identified by the TV. The TV still does not recognize the source components.
Again, same is true of the Xbox One X. The TV cannot determine that the signal is from an Xbox One X when going through the AV7705. Hooking the Xbox up directly to the TV solves the problem.
3. Marantz had me look at the Video information displayed in the settings. The signals appear to be unchanged when video conversion is off and correctly changed when conversion/i/p scaling) is on (1080p/24hz forced output is output correctly). Again, the TV does not seem to care.
4. Tried each of the four HDMI ins on the TV.
5. On the TV side, I have tried to turn on and off all that I can. Interestingly, the "film mode" feature is not selectable (when run through the AV7705) even for cable TV from the Tivo, even if I try to force 1080i from the Tivo box and or AV7705.
Marantz did not have an answer and is taking it to the engineers. This is a very subtle thing. Can I hook all sources through the AV7705 and have content play? Yes. Does the content play in 4K? Yes. Do I get the enhanced 4K content? Not sure. The Xbox One X picture looks much better when run directly to the TV and even asked me to turn on more advanced features when connected to the TV directly. Honestly, I'd be fine routing the Xbox video around the AV7705 if everything else worked properly. But, if I have to route the UHD players and Xbox and Tivo around, what is the point? I'd go back to my AV7701. I like Marantz and want to stay with the brand.
In the end, I think with these more advanced TVs, the source video signal needs to be identifiable by the TV. If the AV7705 is stripping off audio, it needs to leave video alone (completely alone) so that the TV can identify the source device even through the processor. If the TV just sees a 1080p/24hz signal without knowing its source, it tries to convert it to 4k/60hz and there seems to be no way to prevent this.