So my question is: Will the HD Fury vertex or integral used between the Sony and HD621 with proper cables allow 4K video to pass from the HD621 to the Sony?
From my last researches...
4k video can only be sent using HDCP protocol version 2x.
The HD621 uses HDMI 1.3 chips that can handle 4K@30Hz... in theory. But HDMI 1.3 chips use HDCP version 1.x protocol. It can't handshake with 4k video sent with HDCP 2.x
The conclusion is : No 4k video through the HD621.
But there is this HD fury Vertex little box. Its goal is to split the 4k HDMI signal in two :
- one output will give the same 4K signal to feed your 4k tv (if it has HDMI chips with 2.x HDCP)
- the other output will feed the HD621 with a 1080p signal compatible with 1.4 HDMI chips (HDCP 1.x)
As HDMI 1.4 and 1.3 are nearly the same (strictly the same on the audio side, except the Audio Return Channel), it should work.
The previous HD Fury Integral (2016) was able to sent 4K with HDCP 2.x to older devices equipped with HDCP 1.x but Warner and Intel sued the company. (The whole story Here
The 2017 version of the HD fury integral seems to be 99.99% identical to the 2016 version (in terms of functionalities
So it may be be possible to put it between your UHD source and your HD621. But you will only get 4K30p as best UHD format.
I know some UHD disks are in 4k@60p. That's a too high bandwidth for the 1.3 HDMI chips.
If your Sony TV is using HDCP 2.x, I think the best option is the Vertex.