[JohnR]

Wrt the Rane "Pin 1" paper  - http://www.rane.com/note165.html

Has anyone made XLR interconnects using the EMC connectors? I am, I must admit, a little mystified -- if the EMC connector is used at both ends, then the shield is not grounded (DC) at all... Or is it normal practice to use the EMC connector at only the male (receiving) end? (PE, for example, carry only the male EMC connector.

[Speedskater]

I would think, at the receive end only. But they do make both male & female, so?

Wounder if I can find more info in the Bill Whitlock, Jim Brown and Henry Ott papers.

[Speedskater]

Looking further, the shield connects to the shell but not to pin #1, this is the opposite of normal practice. So you would  only use these cable connectors when mating with the receive end chassis.

[JohnR]

I wish they would just show a complete end to end circuit. I've been staring at it and it's starting to make sense to me. The diagrams do show that the shield connects to pin 1, with a ferrite bead as low pass filter:



If I use the analogy of a crossover (!), the shield is connected to pin 1 and therefore to signal ground at audio frequencies (low pass), and to the chassis via the shell at RF (high pass). It's starting to make sense to me that you would do this at both ends.

Further googling turns up off-the-shelf cables using the connector at both ends e.g. http://www.schoeps.de/en/products/kemc


This is the female connector:

http://www.neutrik.com/en/xlr/emc-series/nc3fxx-emc

Looks like I can get it from redco - http://www.redco.com/Neutrik-NC3FXX-EMC-EMI-Protected-Female-XLR.html
 
In my case I'm building the receiving end so will use the matching NC3FD-LX http://www.neutrik.com/en/xlr/dlx-series/nc3fd-lx

I need to think more about the sending end.

[Speedskater]

One Neutrik drawing seems to show the shield only connected to the shell with the ring capacitor connected to pin 1.
Now AES 54 standard, does not permit a shield to shell connect. Even though theoretically it's a good idea. Their reasoning is that the shell of a portable cable could come in contact with metal at a different potential.

But if the connectors are wired with the shield connected to pin 1, the could be used at both ends of the cable.

[rumbleseat]

Since I didn't see a consensus here or elsewhere, I emailed Neutrik USA with this question:

"It is not clear from the information on your site or on the web whether BOTH ends of an XLR cable need EMC connectors or whether just one EMC provides sufficient protection from RFI. If one connector is sufficient, is it better to have a Female connector at the microphone end or a Male connector at the recording equipment end? Thanks!"

Received this reply:

Thank you for your inquiry.  You ask an excellent question.
It is only necessary to deploy an EMC-XLR connector on one end of a cable. This is because the filtering only needs to happen once.  There is zero benefit to filtering twice rather than once. 
The EMC-XLR can be positioned on either the microphone side or the chassis (mixer, preamplifier, etc.) side.  Which side you choose does not matter at all in regards to performance. 

Best wishes,

Fred Morgenstern | Product Director, Neutrik USA
Neutrik USA, Inc. |  4115 Taggart Creek Road | Charlotte | North Carolina  28208-5479
Phone / Text / Fax 704.916.0368
fmorgenstern@neutrikusa.com | www.neutrik.com
 

[JohnR]

Brilliant! Thank you, that really helps.