ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: Grounding XLR shells  (Read 1864 times)

Stephen Swaffer

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2672
Grounding XLR shells
« on: May 30, 2014, 10:43:55 PM »

At the risk of rehashing the "pin 1" problem, I came across a situation while doing some preventative maintenance on our A & H GL3800 that has me curious.  In addition to intermittent static/cutouts on various channels (that we are addressing with a thorough cleaning of ribbon cable, exercising inserts and switches, etc) we occasionally have minor RFI-picking up the local AM station.  I know there are many avenues this could find its way in by...

I also decided to replace some of the XLR jacks and may do all, since some of our issue seems to be at this point.  The factory jacks are Neutrick with pin 1 and shell connected.  It makes sense that connecting the shell to the chassis as directly as possible would help with RFI(as mentioned in some of the references I found).  When I desoldered one of the jacks the "connection" between pin 1 and the shell literally fell apart (it is just a spring tension connection).  The shell grounding connection is also designed to be connected to the chassis through one of the 2 mounting screws for the jack.  Interestingly, A & H only uses one screw per jack-and the one that should ground the shell directly to the chassis is not used.

Something  to consider, or not?  Not trying to attack A&H-the board has served us well IMO it was a very good investment.
Logged
Steve Swaffer

Kevin Graf

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 344
Re: Grounding XLR shells
« Reply #1 on: May 31, 2014, 09:27:17 AM »

The Audio Engineering Society has Standard #54 about XLR shells. The standard is the cable shells not be connected to the shield.  They worry that a portable cable's shell could easily with any metal object that's at some other ground potential. But from an interference point of view, connecting the shell to the shield is a good idea. So if it's a permanent installation I would ignore AES #54.

When installing XLR chassis jacks remember that pin #1 connects to the chassis not to the circuit common. However if there is phantom power involved, doing it correctly could be a challenge.
Logged
Speedskater

ProSoundWeb Community

Re: Grounding XLR shells
« Reply #1 on: May 31, 2014, 09:27:17 AM »


Pages: [1]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.027 seconds with 23 queries.