Swizz Army tells all! Some mic cables are wired to the plug?

Just got my Swizz Army 6-in-1 cable tester. Oh, the things we learn.

Like this:

I've noticed that some of my mic cables have their XLR 'Out' plug pin 1 internally connected to the plug housing. Other mic cables I own do not.

Question I have is.... when I need a longer cable run, is it ok to connect one of these non-ground shielded mic cables (that is, with pin 1 NOT connected to the plug housing) to one of my 'properly' grounded ones? What happens when I do this?

I'm actually asking because I'm trying to troubleshoot a long-standing problem in my rig - involving occasional intermittent (grrr...!) 'doubling' and 'phasi-ness' on tracks I record. Can't seem to track it down; maybe it's related to this?

Anyway.

Adam

daisy-chaining cables from shorted to non-shorted is no problem. The second shell gets shorted by the first.

The only time there might be a difference is if there's a required break at the destination. As soon as the signal travels 1 inch down the cable, there's no fourth conductor (unless it's a special Neumann cable!) to determine whether they were ever connected.

The only difference as far as daisy-chained cables is when NEITHER of them have the connection; then your cable is unshielded for about an inch of it's travel, essentially insignificant.

MOST mics have the two joined at the mic, though I think some Neumanns (early U87s for example) might have the seperation at the mic, allowing the option to keep Shield and phantom 0Volts seperate.

This is a distinction which is largely ignored by most mic manufacturers and so most cables into most mics won't make a bit of difference.

Keith

I'm trying to troubleshoot a long-standing problem in my rig

Click to expand...

What´s your rig? Sounds like a software monitoring problem.

I'm actually asking because I'm trying to troubleshoot a long-standing problem in my rig - involving occasional intermittent (grrr...!) 'doubling' and 'phasi-ness' on tracks I record. Can't seem to track it down; maybe it's related to this?

Click to expand...

Hmm pin 1 issues will cause hum problems not doubling or Phasi-ness without knowing your system, A DAW? it's most likely latency. I suggest one of severial corrections. Change the playback buffer, 2. If PT LE or m-powered use low latency mode when recording. The worst would be the nudge the tracks until the phasi-ness goes away...

Generally the XLR shell should not be connected to the cable shield. Causes more problems than it solves.

agreed. it can screw up some carefull grounding inside the preamp or whatever

I love my swizz army tester. It could use a few more features, but it's a great time saver.

Although......... Check this out:
http://www.behringer.com/CT100/index.cfm?lang=ENG
Look familiar? :roll:

We used XLRs as headphone connectors back in the UK. When we used QUAD 405 and 520 amplifiers, the speaker output ground would send the amplifier absolutely BESERK if it saw a short-to-signal-ground at the end of a long cable. The answer was to use color-coded cables for headphones, tested ground-link free.

I kid you not, it would KILL people wearing headphones fs you inserted a grounded-shell XLR into the wall connector!!! -It didn't care from that point onwards though; extensions could be any variety.

The practical upshot as it affects my philosophy on this, is that for things like AES digital cables the inch of 'non-shielding' might be worth correcting if it's going to be used near interference-sensitive stuff, but for most conditions it might be safer to use non-grounded shells.

Your Mileage May Vary... -and almost certainly will.

Ethan, that Behringer is a direct copy. It even does the same lamp test if you slide the switch one click up while holding the button. (you did know about that one...-right? :wink: ) -For a fraction of the cost of the original though, I'm all about the Bear-wringer!

Keith

Thanks for all the replies guys, learned a lot as always...

BTW, my 'doubling' problem is most likely a soundcard issue (RME HDSP 9652) - interacting poorly with Nuendo. Still can't figure that one out; problem only seems to happen when I use ASIO direct monitoring.

Wish RME had less surly support.

Adam

direct monitoring involves the latency setting of teh card.. i rarely do direct monitoring for this issue too..
It's normal..
but if i can remember correctly, the rme have a patchbay software where you can route any in to any out.. do that for monitoring, give it a try.