Cross-talk in multipin connectors?

[Derek H]

Here's a question that I keep wondering about every time I go to wire up a new cable for something that has multiple channels on one connector... Will this cable be prone to cross talk or other kinds of signal interference?

More and more devices are using multi-pin connectors for various input/output. Take the Nomad for an obvious example, with it's several inputs and outputs on TA5 jacks. How concerned about cross talk should one be when wiring various cable harnesses for use with these kinds of connectors? For example, my Zaxcom TRX900STA150 transmitter has a single TA5 jack utilized for two channels of analog audio input.. would I be at risk of cross-talk between channels if I made a cable that ran from my mixers 10-pin Hirose jack straight to the TA5 using something like Canare starquad? As a rule of thumb does one need to stick to individually shielded, twisted pair channels (separate cables) for this kind of application?

This doesn't only apply to Zaxcom. I/O on increasingly random multi-pin connections seems to be a trend going forward. Just wondering what good cable making protocol for these situations should be.

Any thoughts? Any one ever encounter a specific problem in the field related to too many ins or outs on one connector or within the same cable jacket?

[soundslikejustin]

Are you talking about sending a stereo (or 2 channel) signal down a single piece of starquad? It might be susceptible to cross talk, yes. Canares own multi-channel twisted pair cables that are designed to have multiple signals (even at wildy different levels) sent down them are very good at prevent crosstalk as every pair is individually shielded from the others. It's why you don't see camera breakouts made from 6 conductor cable...

[Derek H]

Yes, I realize there are specialty made cables from Canare and others for this purpose, but you're not going to fit any of them in a TA sized connector.

Just wondering what most folks do in this scenario.

[soundslikejustin]

For a stereo out? I'd do 2 separate cables of Mogami 2739 or 2769, and if you really wanted them to be locked together, use some spaced heatshrink (to keep it flexible) or some Techflex. I'm the the process of making these exact cables at the moment, with my own very low profile connectors (Kortwich style) on the end.

Basically this:

but with low profile plugs.

[Mark Vesterskov]

The multi-pin connectors are not an issue - they are not prone to crosstalk, as there is so "much" distance between the data pins, that is does not represent an issue. As you conclude, the problem is in the cabling, where we have to wire up all sorts of crazy adapters from one proprietary format to another, requiring specialist cable with extra sheilding between pairs.

I'd do something like Justin, if its not possible to squeeze the proper cable into the connector.

[Jack Norflus]

For a stereo out? I'd do 2 separate cables of Mogami 2739 or 2769, and if you really wanted them to be locked together, use some spaced heatshrink (to keep it flexible) or some Techflex. I'm the the process of making these exact cables at the moment, with my own very low profile connectors (Kortwich style) on the end.

I've done the same thing using the Mogami cable with a few pieces of heatshrink as Starquad isn't recommended. I spoke to an engineer at Canare and he said in a short run I might be able to getaway with it - but its not designed to run two independent signals and the possibility of cross talk does exist.

So I didn't want to chance it.