Help with the path of our sound

[Tj Hopland]

I was curious how StudioHub did their cables where they split into multiple cables. My guess is the RJ is on a small PCB and the cables solder to the PCB and in this case the whole works gets molded in plastic. I'm guessing someone must sell an RJ with a small PCB with solder pads or screw terminals. Home depot used to sell a wall plate with a RJ45 and decent size screw terminals on the back. I used to use them a lot for dealing with GPIO automation stuff.

[Josh Jones]

Likely a PCB, I've never cut one open. As I mentioned, I've made my own with punchdown keystone jacks. Not the most durable thing in the world, but it works. I've also used cat5 for distributing 10MHz sync through buildings using off the shelf video baluns. I'm also building a patch panel for my CP650 to select either the DTS box, or a blueray player using RJ45 jacks on a panel.

[Brad Miller]

Likely a PCB, I've never cut one open. As I mentioned, I've made my own with punchdown keystone jacks. Not the most durable thing in the world, but it works. I've also used cat5 for distributing 10MHz sync through buildings using off the shelf video baluns. I'm also building a patch panel for my CP650 to select either the DTS box, or a blueray player using RJ45 jacks on a panel.

Assuming your bluray player has 6 RCA outputs on it, why not just make a RCA to DB25 cable and then use a DB25 switch box like this to share that format 11 input?

https://www.amazon.com/CableWholesale-Way-Switch-DB25-Female/dp/B000I9B2K0

I know quite a few setups that do exactly this.

[Bruce Cloutier]

Ha. So I am not getting updates from this thread. So you guys ran on and I have to play catch-up. They're probably being filtered as spam. Nice.

At this point this A/B thing will look to the JNIOR like a relay module. In other words, we can make this look like a relay output from the JNIOR. I haven't gotten that far. That's all firmware and, well, that's the easy part. So protocols are what you use to toggle relays through the JNIOR.

I have found some Telecom thru-hole relays (dual coil latching) that will drop a good $10 off my cost. I have to rework the design now. To be honest my supply chain is in total disarray. It is a mess. All related to the tariffs and the AI related hoarding I am guessing.

The unshielded RJ45 pairs cut another, maybe, $3 from the cost. Don't hold me to it but that might get the sell price down to around $165 where I think we thought it would be originally.

If this were to be analog audio then I would be really concerned about the shielding. I might even make sure there are ground planes in the PCB and that traces are length and impedance matched. But AES is digital and should not be sensitive to it. It would be nice to pass the shielding through but that metal on the connectors adds more cost than it should. I will continue to look at it. Shielded would be my preference. You guys need to chime in as to whether the cost advantage outweighs the risk.

The screw terminal suggestion has been noted.

[Ryan Gallagher]

Ha. So I am not getting updates from this thread. So you guys ran on and I have to play catch-up. They're probably being filtered as spam. Nice.

As you were not the OP you'll only get notices of replies like this one that quote you. If you are interested in following the whole thread I think you have to click the big [+Subscribe] button at the top, though perhaps you did wisely did that already and are still experiencing missing notices. ;-)

[Josh Jones]

Assuming your bluray player has 6 RCA outputs on it, why not just make a RCA to DB25 cable and then use a DB25 switch box like this to share that format 11 input?

https://www.amazon.com/CableWholesale-Way-Switch-DB25-Female/dp/B000I9B2K0

I know quite a few setups that do exactly this.

I don't have room for one of those switches, and the quality of the new ones is pretty bad. One 6" cat5 jumper will do all I need, plus I have other slots in the panel for other I/O needs.

[Steve Guttag]

I suspect that you'll find that if the product ever has to meet any country testing for noise, shielding will be required, including shielded connectors.

[Jim Cassedy]

<edited> Assuming your bluray player has 6 RCA outputs on it, why not
just make a RCA to DB25 cable and then use a DB25 switch box - - to
share that format 11 input? I know quite a few setups that do exactly this.

We use exactly that sort of setup here. Our main auditorium uses a TRINNOV audio
processor, but our 35/70mm sound (optical and magnetic) go through a CP-650.
The switchbox toggles the 6ch Analog Inputs on the Trinnov between the analog
outs of the CP-650 and the ouptus on an OPPO blu-ray player.

"Actual Photo"
T1_Switchbox.jpg

[Tj Hopland]

I guess the 'fallback mode' with one of those boxes if you had issues would be to just sick the cords together if you had to. Would want to pre check the cable genders and have a gender changer laying there to be ready if needed.

[Ryan Gallagher]

I guess the 'fallback mode' with one of those boxes if you had issues would be to just sick the cords together if you had to. Would want to pre check the cable genders and have a gender changer laying there to be ready if needed.

Yeah you mean if you were worried about the quality/reliability of a cheap A/B box. Just have a backup way to hard patch without the box.

same is true for Bruce’s box if you are worried…. Just keep a couple RJ45 barrels near by.

[Bruce Cloutier]

Jim says "Actual Photo". Isn't it great how we have ruined photos/videos as evidence of reality?

But you have to applaud the use of duct tape. If you trust Matt Damon's word, it even works on Mars!

[Ryan Gallagher]

[removed my duplicate post, draft feature was acting weird]

[Bruce Cloutier]

Some of the old DB25 switch boxes only switched signals required for RS-232/422/485 didn't they? So you would have to be careful to make sure the one you have switches all 25.

I am still debating the shielding. By this I mean the metal enclosure around the RJ45 jack. Any shielding around the wire pairs will be passed through and switched. That's only defined for the DB25s I think. As for the outer cable shielding, there is this whole thing about connecting the shield only at one end to insure that no current flows though it. I have the shields currently all tied together between all six RJ45s.

Logically maybe I should keep the channel 1-8 RJs separate from the channel 9-16 RJs? It makes sense to pass the external shield through the A/B switch but it is probably not right to bridge the A cable shielding to the B cable shielding? But that is not worth being definitively switched.

The metal covering the jacks are more to keep EMI from leaking out of the device from other sources.

CAT6 cables don't have the external shield do they? I am not sure that I have any around to check. Do any of you see cables wherein the external shielding can connect to the jack housing?

So this is probably not worth a lot of worry. I just don't have a good rule-of-thumb posted on the wall.

[Bruce Cloutier]

2026-02-13 10.47.35.jpgAnswered my own question. The outside is metal shielding.

To definitively handle this shielding question, I could add another relay. I know that you guys are not all THAT concerned with cost. You can tell that I am trying though.

BTW, down at the bottom of that rack is a legacy Doremi DCP-2000 that is up for grabs if anyone needs parts. It has no miles on it. It doesn't have everything you need to serve video. We use it from time to time to validate protocols.