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#1
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
I was inspecting some wiring on an XLR cable yesterday and I noticed
some questionable wiring. On one end of an XLR cable, the shield (which goes to pin 1) was also soldered to the cord strain relief clamp which is electrically part of the metal connector shell. Is that correct? I found the connection on ONE END ONLY - not at both ends. Thanks. Lou |
#2
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
In article , Mr. C wrote:
I was inspecting some wiring on an XLR cable yesterday and I noticed some questionable wiring. On one end of an XLR cable, the shield (which goes to pin 1) was also soldered to the cord strain relief clamp which is electrically part of the metal connector shell. Is that correct? I found the connection on ONE END ONLY - not at both ends. Thanks. Lou I am not an everyday user of XLR, but, depending on the use, like balanced or single ended, you only have 3 conductors and a shell. If you want balanced with a signal reference, then the shield should only be connected to ground via the shell on one end. The signal ground should not also be connected to the cable shield. If your using single ended, then you have an extra pin to play with. One pin can be ground which can be connected to shield on one end, but can also be tied to the ground pin, ans signal reference ground can be separate. The cable should be oriented with the ground connection on the end with the lowest noise or best ground. You may only be concerned with the on ONE END ONLY comment. This is to avoid a ground loop interfering by injecting ground current noise into the signal path. greg |
#3
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
Mr. C wrote:
I was inspecting some wiring on an XLR cable yesterday and I noticed some questionable wiring. On one end of an XLR cable, the shield (which goes to pin 1) was also soldered to the cord strain relief clamp which is electrically part of the metal connector shell. Is that correct? It's not uncommon to tie the shield & pin 1 to the shell of the XLR connector. 99.9% of the time it won't make any difference whether you do or don't - all it does is add two more inches of (uninsulated) shield. The other .1% of the time, you're on your own. (c: I found the connection on ONE END ONLY - not at both ends. Thanks. Lifting the shield at one end is common practice, but it's usually done via the jack rather than the cable. But this isn't what you're describing. I'm at a loss to explain a reason, most likely there isn't one. //Walt |
#4
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
"Mr. C" wrote: I was inspecting some wiring on an XLR cable yesterday and I noticed some questionable wiring. On one end of an XLR cable, the shield (which goes to pin 1) was also soldered to the cord strain relief clamp which is electrically part of the metal connector shell. Is that correct? I found the connection on ONE END ONLY - not at both ends. Thanks. Lou This is somewhat of a religious issue, but I'll try to boil it down to the basics. One ought to ground the connector shell, so that you get uninterrupted shielding along the entire length of the cable, including the couple inches inside the connector shell. One ought not ground the connector shell because the connector shell touches another grounded thing, one then creates a ground loop, adding noise to the interconnection. 'zat help? --Dale |
#5
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
Dale Farmer wrote:
This is somewhat of a religious issue, but I'll try to boil it down to the basics. One ought to ground the connector shell, so that you get uninterrupted shielding along the entire length of the cable, including the couple inches inside the connector shell. One ought not ground the connector shell because the connector shell touches another grounded thing, one then creates a ground loop, adding noise to the interconnection. Good synopsis. I'd simply add that a shield that stops an inch short or a two-inch diameter ground loop aren't worth to losing sleep over. //Walt |
#6
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
"Mr. C" wrote:
I was inspecting some wiring on an XLR cable yesterday and I noticed some questionable wiring. On one end of an XLR cable, the shield (which goes to pin 1) was also soldered to the cord strain relief clamp which is electrically part of the metal connector shell. Is that correct? Yes. I found the connection on ONE END ONLY - not at both ends. That is indeed the proper way to do it by my reasoning and experience, I connect the shell on the female XLR to cable shield and let the one on the male XLR float. The purpose is to prevent both shells from floating in case the cable is used as extensition cable because that can be a cause of hum injection if the cable shell is touched or on the ground. It is a subtle issue for a balanced connection, but not the day the cable is used for an unbalanced connection. Empirically determined. Not connecting the shell on the other plug is to prevent muliple ground paths, one through the shells and one through pin 1 from existing. Connecting the shell to the cable shield is irrelevant in case both ends of the cable is plugged into an apparatus, say a mic at one end and a preamp at the other end. Lou Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#7
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
Mr. C writes:
I was inspecting some wiring on an XLR cable yesterday and I noticed some questionable wiring. On one end of an XLR cable, the shield (which goes to pin 1) was also soldered to the cord strain relief clamp which is electrically part of the metal connector shell. Is that correct? I found the connection on ONE END ONLY - not at both ends. Thanks. Connecting the wire ground to XLR connector shield is not a recommended practice in audio wiring. -- Tomi Engdahl (http://www.iki.fi/then/) Take a look at my electronics web links and documents at http://www.epanorama.net/ |
#8
Posted to rec.audio.tech
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Should XLR shield also be tied to the shell?
Thanks guys for the input.
Just to make it clear to some that posted, I am using this as a balanced signal line meaning the two signal lines (on pins 2 and 3) are not connected to any ground or shield anywhere. The shield is connected to pin 1 on both ends as it should be. But on one of the ends, the pin 1/shield connection is ALSO soldered to the connector shell. I can understand only tieing one point to the shell. It does protect the balanced lines from interference as long as it is grounded somewhere. And grounding it at one point does prevent ground loops from occuring. Thanks again for the input. I feel more confident in the cable now and I will not change anything. Lou |
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