I’m new, but this is also a goal I share — the quest to build an AVR from separates! Are you trying to use the HDMI ARC feature from your TV, or just send normal HDMI video+audio+control straight into the extractor? The various control-over-HDMI features are called HDMI-CEC.
I’ve been researching this subject, and to get volume control you will need a more sophisticated processor, rather than just a signal extractor which is too “dumb” to participate in HDMI-CEC or modulate the volume. Here’s the most informative thread I’ve found on the subject:
https://www.audiosciencereview.com/...ork-music-streamer-for-active-speakers.13918/
I’ve looked a bit, and there’s a few different options on the market that could serve you:
- You posted a .de link, maybe you can try the Canton Smart Connect? It does 5.1 pre-amp out and claims to have HDMI-CEC volume control.
https://www.canton.de/en/products/smart/smart-connect-5.1
- Just get an AVR with the pre-amp outs that fit your use-case. Many AVRs have at least left and right, and the fancier ones have more channels. You’ll be able to take advantage of whatever EQ, etc, that the AVR has — but also it’s gonna be big and bulky, and you end up paying for a lot of amps you might not care about.
- There’s a class of streamer that bundle a digital streamer, pre-amp out, and a single HDMI ARC input, and sometimes a ~80w stereo amp. The Bluesound Node fits this profile. NAD has several options like the NAD M10 that include an amp.
- there are a couple of AVR “processors” that do have a bunch of channel outputs and no amps, like IOTAVX AVX17
https://www.iotaenterprises.co.uk/products/iotavx-avx17, but there are a few more cheaper options if you search around — I can’t find them in my notes.