Topic: 7-Pin XLR hose... Will this work?

[JLMoore3rd]

I'm trying to build a hose that can run 2 xlr's & a 1/8" stereo headpone return (from a Wendt X3 pre to a digital video camera- I need the return in order to double-check the sound feed).

My question = Can I use the 7-pin layout like this:
Pin 1 - shield for both 3-pin xlr's & ground for 1/8" headphone
Pin 2 - red (hot left xlr)
Pin 3 - black (left xlr)
Pin 4 - red (hot right xlr)
Pin 5 - black (right xlr)
Pin 6 - right (headphone)
Pin 7 - left (headphone)

Will the fact that I'm sharing pin 1 with the xlr's (which works in a 5-pin xlr) with the ground in the headphone cause any interference with the sound?

[oleg]

no

[JLMoore3rd]

Okay... "no" it will not work or "no" it won't interfere with the sound?

Which no?

[notlance]

It should work.  In most gear, ground is ground.  But build it and try it out before you use it.  Untried cables always seem to fail the first time they're used in the field!

[ghellquist]

Same belief here, it should work.

I assume your going to make 7 pins on each side of the long cable and then short harnesses going to the Wendt and camera respectively.

First of course, how you connect things in the connector is only part of the story. The next part is the cable. It of course depends a bit on how long you make the cable. Balanced signals can run quite a long way, 300 feet is not unheard. But the unbalanced return signal will be a bit more susceptible to interference. I would believe you could run maybe 100 fett without too much trouble, my guess only.

You could definitely run this in a 6pair cable with single shield. Some are to be found, again some of them are a bit on the bulky side. Soldering 7 pins in the cable is crowded, takes a bit of experience. Running the unshielded return next to the mic level signals may get you a bit of interference between the two, but again, my guess is that it would work.

Next again is the possibility of ground loops in the harness going from the 7pin to the Wendt. If you get into troubles here, you could diminish it by connecting the pin 1 ground only to the RTN ground, not to the 3-pin XLR-s. The output signal as such only goes on the hot/cold cables, the ground is there to make sure that there is not too much of different ground reference for the two units. The RTN signal, beeing unbalanced, of course referrs to ground. I would do this only as a trouble solving effort though. Same kind of discussion goes for the camera side of things.

A final note: 7 pin XLR-s are used here and there for connecting tube microphones to their power supply. This means 200V or a bit more. If accidently connected to the wrong output, you would fry your equipment.

// Gunnar

[oleg]

Okay... "no" it will not work or "no" it won't interfere with the sound?

Which no?

no interference  as long you use good quality cables
the other thing  , better go line level  to the camera to get less crosstalk between  the send and return which can appear  by sending mic level parallel to return which is line

[JLMoore3rd]

Thanks to every for the feedback. I wimped out on the 7-pin XLR soldering &  just added the connectors to the hose:



Since the Mogami 2602 has 4 shielded pairs I figure it should hold up pretty well... The next time I need to build a breakout hose I think I'll go with the Canare L-4E3-P because the jacket looks thicker on the individual channels.

John "Alpha Flying Monkey" Moore
sound.flyingmonkeystudio.com

[oleg]

change the mini jack on camera end to right angle  if you want it survive after 2 weeks .
i don't see the 7 pin brake out on your cable , make it for fast disconnection , the tail have to be long enough to be able go around the handle what make straight relief .

[JLMoore3rd]

Good point on the right-angle... I tested the setup & am going to swap that out ASAP.

I didn't do the 7-pin XLR connector- I've had enough small soldering for a while!