Recommendations/sources for video cables and patch cables

LZX RCA cables are great, haven’t found a better one yet. :smiling_face_with_three_hearts:

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They look like there is no breaks in the RCA ring. My experience with that type has been hit and miss, some female rca won’t fit them, like my rca to BNC adapters for my V4ex. Do they have breaks in the ring? I love the colors.

I’ve found this type to be a bit stiff for patching, but great for permanent / one time connections. How about you? :smiley:

The black market RCA cables are definitely stiffer than the Amazon ones in my experience.

Ah yea, just to be clear, this in in reference to the ring, it can be tight, but fits most things. Not great for repeated patching with the tightness I experienced. :smiley:

Hi all,

I’m trying to work out how I can connect my dslr camera to my lzx system in the absence of a visual cortex, chromagnon, or TBC2 and am wondering if anyone can speak to the effectiveness of mono rca to 3.5mm aux (ts) cables in this context.

My plan was to use an adapter to convert my camera’s hdmi output to composite video, and then another adapter to convert from composite to component RGB. However the composite to rgb adapter outputs via three RCA jacks. I am curious if it would be possible to use one of these cables or similar to feed RGB signals into my lzx system or if there would be other voltage or syncing issues to consider.

Thanks!

I know you’re talking about input, but what are you using as an output module from your LZX system? Most video output modules (aka encoders) need sync as an input somehow in order to generate the valid video signal output. Additionally, some non-encoder LZX modules need to be sync’d. This is one issue with your plan, though it might not be insurmountable, since the RGB format of the converter you mentioned is RGsB so it has sync mixed into the green channel. Depending on your LZX system, you may be able to mult the green channel and feed it into the sync input of your output encoder. Though it might not work too well since you’ll have signal mixed in with your sync. That’s another issue.

The last issue that pops to mind is the voltage levels. Composite and component video both have a video signal peak of about 0.7V, whereas LZX expects video peaks of 1.0V, so your image will be a bit dim. Additionally, I know composite video is usually AC-coupled so I wouldn’t be surprised if component video is too (since in a lot of ways they’re very similar), so you’d want to DC-restore your signal. (If you’re familiar with modular audio synthesis, this is kind of like converting a bipolar LFO to a unipolar LFO, sort of.) Without DC restoration, your signal will be even dimmer that the 0.3V difference noted previously.

So, now that I got all that issue explanation out of the way, there may yet be hope, maybe…

You mentioned that you have an LZX system… What’s the sync source for your system? And what’s your output encoder? If you’re working with a Cadet system (or a mixed system with Cadet 1 as your sync generator), then you’d just need this: Syntonie VU003
That handles the YPbPr conversion and sync stripping, and you’d pass the green channel through your Cadet 1 before going into this, in order to sync your system (and output encoder).
(Alternatively, you could use three Cadet 3’s, but those are likely hard to find.)

If you’re working with a LZX Visionary system, I think that Syntonie module should work for that too.

Wow thanks for the thorough reply!

I’m currently using a Memory Palace as the master sync generator and using it to clock a Fortress (and when it arrives in a few days a Diver as well), which then feeds back into the MP’s rgb inputs and the MP composite output is then going to my projector.

Sounds like that syntonie module is pretty close to what I’m looking for, would that also take care of the .7V voltage issue if i were to add a Cadet as the master sync source instead of using the Memory Palace as the sync source? This sounds preferable to multiplying the green sync from the adapter and feeding that into the Memory Palace’s sync in, if I’m reading your explanation right.

Yes, I believe the Syntonie VU003 does DC restore the signal.

I don’t think you can sync a Memory Palace from a Cadet 1. Cadet 1 only produces 14-pin sync, while I believe Memory Palace only takes RCA sync. If you added a Cadet 2, that would produce RCA sync from the 14-pin sync (as long as you don’t plug anything into the inputs of the Cadet 2).

Unfortunately though there’s a problem with using the Cadets… They’re no longer in production, and they’re DIY. You may be able to find places that still have some for sale, but if you can’t solder them that won’t help. (They are fairly easy through-hole builds, though, so you don’t need to be a master, though there are a couple SMD parts on them that are a bit harder.) Or you may be able to find someone selling them already built, but there’s no guarantee you can find that.

So it might be best to try syncing the MP via the green channel. Before getting the VU003, you can test out syncing the MP via a sync+video signal easy enough. Just set it to be externally sync’d and plug any composite signal (or component green channel) playing some video into the sync input and see if the MP outputs its normal output without glitching. (If it does glitch, you’d want a “sync extractor” or “sync separator” to get the sync without the video, and there are a number of small DIY circuits that could be made to do just that.)

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Sorry it’s not more straightforward. We’re at an annoying time right now in between major LZX series, so there aren’t a lot of options for certain functions.

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Thanks! You’re right about this being a weird annoying in-between time, part of me just wants to wait until chromagnon and tbc2 ship but the other part of me feels like there should be a way to do it in the meantime, so I will try out the method you described.

Just to be extra clear though, since you mentioned that any composite signal can be used as a sync source for the MP: do you think I would be able to use a Syntonie VU001 to multiply my composite signal and then send one of those composites into the MP sync in, with a second composite signal going from the VU001 to my composite-to-component adapter, and then into a VU003 from there to convert to RGB?

Thanks again for the info!!

Maybe? Just to be clear, I don’t have a MP, so I’ve never tried syncing one with a non-blank composite signal. Hopefully others can chime in about whether that works, or if it needs a clean blank signal to sync with. (Or since it sounds like you might have one already, you can try it out and see if it works. It shouldn’t damage it – the worst I can imagine happening is it just doesn’t sync right.)

As to your signal chain: maybe? The VU001 should do what you expect, as should the VU003, but I can’t say whether or not your composite-to-component adapter will keep the output in sync with the input.

Oh! I know what should work better (again, assuming the MP can take a non-blank composite signal as sync):

Pretty much what you described, but move the VU001 to be after the composite-to-component adapter, and run the Y output from the c-to-c adapter through the VU001 then to the MP and the VU003’s Y input. The Y channel carries the sync, so that way, you’ll end up syncing the MP with the same signal you’re feeding into the VU003.

(Sorry if that hid the last few posts for everyone – I didn’t realize what would happen. I flagged the discussion about getting video into the MP as off-topic in hopes they’d be moved to a separate thread, since it’s not really about video cables or patch cables.)

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Good move, worthy of its own discussion and keeps this thread on topic

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Does anyone have information on which brands of 3.5 mm patch cables have the best fidelity for video? The least high frequency signal loss? Especially with HDTV formats, it makes a huge difference. I’m seeing noticeably softer video using TipTop Audio StackCables, compared to LZX RGB mini-snakes.

Shielding is nice, but I’m less concerned about noise than about signal loss. In a perfect world, someone would manufacture 3.5 mm cables optimized for video. Robust, high fidelity, well shielded.

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I really like the Control Cables

It’s been mentioned that extra shielding causes capacitance, which degrades high frequency video signals.

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At first, I didn’t really noticed a difference between cables when using a linear power supply/SD system based around Cadets. Later, I switched to a lighter case powered by switching supplies, and the cheap no-name cables I was using were picking a lot of noise from the PSU, so I went for Polar Noise Shielded cables, which helped greatly with the noise.

Then I started building a system around HD modules, and that’s where cables shielding/length started making a difference. Both parameters effect the capacitance of the cable, which basically creates a filter between the two modules connected, hence why it helps with high frequency noise coming from a switching PSU.

Here are some tests I already posted on the Discord a while ago, with a black and white checkerboard in 720p60 as a source, with direct connection from VU003B to VU007B.

Same cable length, different shielding:

Same shielding, different cable length, Polar Noise Shielded iirc:

I’ve also tested with alligator clips (basically cables with no shielding), it does improve the bandwidth but picks up a lot of noise (from Capsule PSU iirc). Second capture is with RG179 cable and Rean jacks, RG179 is specified at 64pF/m, jack sockets also adds a bit of capacitance, so didn’t really noticed a difference with RGB minisnakes. Last one is Tendrils, which are up to par with Polar Noise Shielded from what I’ve tried:

Haven’t tried other cable types, though seems like RGB Minisnake performs the best, then keeping connection between modules short does also help, but it gets tricky with dense patches and/or passive splitting. Also, all those captures are 720p60 which is the format that requires the most bandwidth, so going for a lower resolution/framerate could also help.
Seems like it will always be a tradeoff between bandwidth vs noise immunity, though I only tested with VU003B/VU007B with a Capsule power supply, I guess Gen3 modules might be less prone to noise since they all have their own integrated power supply.

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They should be – part of it is that the scale of any noise is much lower with +/-5V power rails than +/-12V rails. With Capsule power, we measured 1-2mV under full load. With the Gen3 integrated power, it is less than 400uV. Anything under 3-4mV is effectively ignored, once the video is digitized at 24-bit RGB.

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