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

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

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

"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

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

"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 *
*******************************************

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/

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