HDBaseT AVLC - is it really visually lossless?


Well-known Member
As no-one is broadcasting or streaming or supplying discs in 4:4:4 DV @60Hz, the only folk who that is likely to affect is going to be gamers; and if you're gaming and able to concentrate enough to spot the difference between 4:4:4 and 4:2:2/4:2:0 at normal seating distances for 4K then I think you're probably not doing it right...! I don't believe there is any source that refuses to do DV at 60Hz because it can't get a 4:4:4 link?

I think HDBT is a good solution for many applications, but it is always trailing the capabilities of direct HDMI solutions. If you want to be right at that bleeding edge then don't go HDBT. For what it is worth I don't think it has much of a future as single links past 18G (they've not even got there fully yet).

Back to the OP; they don't have a conduit and seem to want to avoid the building works and / or exposed cables; if they can get the Wyrestorm solution for £100 from a trusted source, and it supports the formats they need, I'd have just bought it already as at that price I'm sure it could be punted onwards for no loss; it's almost not worth the thought energy. I paid more for my Atlona at trade cost, and I'm happy at that. If it works and does the job for them, great, if not, move it on and time to get busy with the tools. Job done.

You're right, I should have just grabbed it. But I dithered and its gone out of stock now :/ As you say I could have just sold it if it didn't suit my needs :(

Will keep an eye out for another one. Or get my tools out and run that new cable :D


Well-known Member
Having kicked myself for not getting the Wyrestorm extender, I decided to cause myself more pain :)

Google ads (having obviously watched my searches) showed me the following connector. Given it was through hole I thought it would be easier to solder.

Gave it a shot today and first try 8 bit worked, but with sparkles again. I went back and checked impedance across the pins and touched any showing slightly higher impedance. And it seems to be working at 8 bit. Watched Liverpool game today and no drop outs. And no obvious picture issues.

Will know for sure when I watch an anamorphic movie as any sparkles will be easier to see in the black bars.

I'm keeping an eye out for the wyrestrom to come back in stock and will just grab it. But for now this keeps me ticking over (provided no issues show up) as I believe Sky don't broadcast in 10 bit yet anyway?
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Well-known Member
Also I noticed a possible issue with the cable, which makes me wonder if it would struggle even if it handn't broken.

To make sure there were no cross connections I buzzed out thoroughly before connecting to the TV. I noticed the TDMS shield pins were buzzing across (pins 2, 5, 8, 11). I have another cable of the same type, so I checked that and again the shield pins were buzzing across, so it seems to be by design.

On the newer cables I have these pins dont buzz across. I dont have the spec, but I presume they should be isolated.

There's also a "case ground" connection on the board, which connects to the outer part of the HDMI cable. But I'm not sure what this should connect to on the cable. Given the TDMS Ground pins buzz across to the outer shield, I wasn't sure if it was a good idea to solder to that. Will have to dig out the broken connector which I've got in a bag somewhere, to see what they had used.


Active Member
I have decided that I am going to bite the bullet and run two new fibre optic HDMI cables with enough bandwidth that will cover 8k at 12bit and 120hz so I am future-proofed. Been onto my electrician and home cinema supplier. For the sake of having the right solution and just needing to do some painting afterwards, I am going to do it correctly and not rely on external solutions to my issue. Even told the wife at the weekend that I need to get some new cables run. ;)

Joe Fernand

Distinguished Member
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Run conduit - that is your future proofing, any cable you install now will ultimately become obsolete.

For the HDMI cable(s) I would look at RuiPro4K Hybrid Fibre.



Well-known Member
Quick update on my success with the repaired cable.

Sky seemed to work at 4k/8 bit. I was reasonably happy with that, but when I tried my Virgin V6 box it wouldn't work at all. Ran a separate cable and it worked fine at 2160p.

Looking through the settings there was no way to specify 8/10 bit. Only an option to set the resolution. Worse still, not matter what I did, it always defaulted to 2160p. So I could get it to work at all over the repaired cable, because even if I set the res to 1080p only, the box would switch to 2160p on seeing the TV's capabilities.

I thought i'd just use my old 1080p extender, but even that wouldn't work with the Virgin box. Either there was an update that changed the way the V6 worked. Or connecting it directly had caused some issue and now it kept defaulting to 2160p even through the extender.

Fortunately the EX-70-H2 came back in stock and I managed to grab it for £75. Using the extender, Sky Q is stable at 4k/10 bit and the Virgin box also seems to be happy. I ran a direct cable to compare and no obvious difference in PQ. But I didnt check exhaustively.

Anyway, I'm happy for now. At some point Im planning to get a carpenter in to create an AV/storage unit. I'll run conduit and a new cable then and should be able to sell the extender to get my money back.

Otto Pylot

To summarize:

HDBT is still stuck at compressed video, among other drawbacks, until the new Valens VS3000 chipsets are available. They were announced over a year ago but there have been some production issues. HDBT connections should always be made with solid core CAT-6/7 cabling (non-CCA and not pre-terminated ethernet patch cable).

Premium High Speed HDMI cables, passive and only copper-based, are still the only HDMI.org certified cables on the market, but they are only good up to 25'.

Active cables of any type still can not receive certification at any length from HDMI.org. It's an on-going work in progress.

Hybrid fiber cables will be the way to go for HDMI 2.1 and beyond for lengths longer than about 20' at present. There are lots of hybrid fiber cables on the market now making all kinds of claims so caveat emptor. There is only one hybrid fiber cable that I know of that is being, and has been, tested by an ATC to meet all of the HDMI 2.0 protocols and is being tested for the HDMI 2.1 options sets following the protocols and testing instrumentation recommended by HDMI.org. But, being as they are active cables, they can not receive the certification or QR label. Hopefully that will change in the next few months as certification for HDMI 2.1 is underway.

As has been mentioned many times, the ONLY way to future proof cabling is to install them in a conduit if you don't have easy access or the runs need to be in-wall. Video standards will always outpace connection standards so you will need to plan ahead and make it easy for yourself to upgrade your cabling as the need arises, whether it be HDBT or hybrid fiber. The most reliable connection is still a single cable, source to sink, with no wall plates, extenders, adapters, etc. in-between.

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