Passive HDMI adapter or cable that can split off digital audio/SPDIF?

[CZroe]

I have an old Sony XBR CRT set with awesome picture quality (SFP tube) but it only takes DVI-D. I can't properly connect a Chromecast to it because it doesn't support SPDIF audio through the DVI-D connector unlike some DVI devices.

Some PC video cards like my old GTX 280 had an internal SPDIF cable for grabbing audio off the PC's sound hardware. Even though they only had DVI output, you would get sound over HDMI with a simple adapter. Because some DVI to HDMI adapters didn't work, it sounds like it used DVI pins which some video-only adapters ignore rather than encoding it with the video or something. That means I should be able to passively split the audio and the video since they aren't streamed together.

A passive cable to split combined HDMI audio/video into HDMI video and SPDIF audio should be possible based on this observation, but I can't find anything like this. I found an expensive active converter that has issues with Chromecast on TVs that don't support 1080p signals (this one does 1080i, 720p, etc), but that really should not be needed anyway.

If I got an AV receiver then it would be connected to my 65“ XBR which already has a working Chromecast setup, so that's not really an option here.

 

[Fallen Kell]

You need something like this:

http://www.monoprice.com/Product?c_id=101&cp_id=10110&cs_id=1011002&p_id=5557&seq=1&format=2

It is a HDMI switch which can split the audio out to SPDIF. You then just use the HDMI->DVI adapter on the cable to your TV.

The PC video cards that did this with the output used a custom pinout cable which had the SPDIF audio going down 1-2 extra pins on the video out which the custom adapter converted to a SPDIF connector (since it is 2 wires, signal and ground).

 

[Ichinisan]

Digital audio is not carried on separate pins. It's encoded along with the video.

You wouldn't be able to separate it with a passive adapter.