Are you aware of such a board with does the 8 channels outputs ?
So having SCK, BCK, LACK and DATA1, DATA2, DATA3, DATA4 (for each pairs of outputs) and then 4 SPDIF/AES outputs.
Because having 4 such boards will be probably too expensive + problem of not enough rooms inside the AVR
You can find old cinema dolby digital decoders with output 4 spdif/aes for 300-500$ (but only dolby digital and not dolby digital plus, but many sources can reencode into dolby digital)
Another option is using a decoder in the source (like bluray or set top boxes) which output to 7.1 LPCM HDMI...
The cost is not linear by number of channels.
The ESS9028PRO chip has 8 channels, so providing 6 channels instead of 8 would just remove 2 output buffers on the PCB and 2 XLR connectors, so not that much components, and everything else would stay the same (ie inputs, transformer, cases, etc...)...
50 euros * 4 XLR = 200e just for an adapter to a 1200e machine, that sounds very prohibitive.
I understood the meridian have 4 AES on its RJ45 output, so I will try to solder my own cable.
But all of that takes time.
I have meridian hd621 and dac8pro.
I use spdif meridian output to an spdif to xlr adapter to the dac8pro.
I have a dropout every 5-10 second or so. So it is not usable.
So I assume the spdif signal level of the meridian is not enough for the dac8pro AES input.
The meridian spdif output to...
But you cannot have an official 4K HDR source displayed through displayPort, like netflix or disney plus.
The content creator requires HDCP 2.2 for that, and that is supported only on HDMI 2.0+.
VRR is an HDMI standard, not a displayport one.
HDMI 2.1 VRR is still a buggy standard, there are...
PC and laptops have less and less displayport and more and more either HDMI or just USB-C.
A displayport to HDMI adapter costs a few dozens of dollars, same for USB-C to HDMI, this is not a big issue.
This just protect you from having to trash your AVR in the bin when a new HDMI standard will...