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Cable Clinic

PostPosted: Fri Jul 28, 2006 3:19 pm
by oddioguy
Time to deal with the myths and black magic of everything cable related.

I'll post some info, rants, and suggestions. Feel free to post your own thoughts, or ask questions.
No question is too stupid. Sure, we may all laugh at you, but you will get an answer, and you will learn.

PostPosted: Sun Jul 30, 2006 9:57 pm
by oddioguy
This one has been with me for a while....

I had a client contact me saying that he was trying to interface his Roland multi-track to his computer via S/PDIF. He had gone to a local music store, and they sold him a cable, but he couldn't get the Roland to communicate with his computer.
"Bring it down and I'll try to help", I say.
So he shows up with his Roland, and an analog RCA type patch cord. I told him to return the cable to the store from which he had purchased it, and passed on this info:

S/PDIF is a digital format that is impedance specific. You may know a guy who knows a guy that uses his stereos' patch cords, and it may even work....but only over very short distances, and error rates are going to be high.
Conveniently, the impedance selected for S/DIF was 75 Ohms, which means that if you have some spare TV or satelite - type coax cable laying around, and have basic soldering skills, you can make your own S/PDIF cables.

Basic TV coax is "RG59", and is about $0.25/ft (yeah, I still use feet....sue me.)
A good but inexpensive RCA connector is Neutriks' part number "NYS352", at about $1.29ea.
Cut your cable to length, solder a connector to each end, and you're done.

Easy.... :-)

PostPosted: Mon Jul 31, 2006 5:48 pm
by Alain Benoit
I extensively use 75ohm cable in the studio trunk lines for CCTV, S/PDIF and Word. I reccomend and useCanare LV-61S. I prefer to terminate with BNC and adapt to RCA where need be.
I think that a hundred box of Neutrik NBNC75BLP7-D cost me under $500 and a 500 foot spool in the vicinity of $150.

PostPosted: Mon Jul 31, 2006 6:22 pm
by oddioguy
U1176 has terminated more cable in the past 5 years than I have in a lifetime.
8-)

PostPosted: Mon Jul 31, 2006 6:36 pm
by Malcolm Boyce
oddioguy wrote:U1176 has terminated more cable in the past 5 years than I have in a lifetime.
8-)
I guess that would make him the Terminator... :roll:

PostPosted: Tue Aug 01, 2006 8:12 am
by oddioguy
Of the peeps that I know on this board, I realize that there is no need to identify the different commonly used connectors.
But....
Would anybody like me to do so?

PostPosted: Tue Aug 01, 2006 1:26 pm
by Malcolm Boyce
oddioguy wrote:Would anybody like me to do so?
Yes please...

PostPosted: Tue Aug 01, 2006 1:55 pm
by oddioguy
Malcolm Boyce wrote:
oddioguy wrote:Would anybody like me to do so?
Yes please...

As it is written, so shall it be done.... :mrgreen:

PostPosted: Wed Aug 02, 2006 10:20 am
by oddioguy
It's the single most popular connector in the (pro audio) world!

XLR (female) - Commonly used for mics and balanced lines. Also used for AES/EBU digital.
Remember kidz....Pin 1 is shield!!

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PostPosted: Wed Aug 02, 2006 10:27 am
by oddioguy
XLR (male) - Illustrated here with an optional coloured boot.

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Tip of the day - Can't remember which end of an XLR cable should be male and which should be female? The guys who do remote broadcast have a saying:

FUCK THE TRUCK!

That should clear it up if you think about it for a moment.

PostPosted: Wed Aug 02, 2006 10:37 am
by oddioguy
1/4" plug. Also known as a "phone" plug from its origin as a telephone switchboard connector.
This example is the "TS", or "tip/sleeve" version, making it appropriate for either unbalanced lines or mono applications.

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PostPosted: Wed Aug 02, 2006 11:11 am
by oddioguy
1/4" phone plug. This is the "TRS", or "tip/ring/sleeve" incarnation. Suitable for balanced lines or "stereo" applications.
This example has gold plating and optional black finish.

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Tip of the day #2 - The connector gender is specified by the contact, thus making the above two examples male "plugs", and not "jacks".

PostPosted: Wed Aug 02, 2006 4:01 pm
by oddioguy
Let the games begin....
This is the military specification version of the above commercial type 1/4" plug. Note the different shape of the tip.
TRS configuration. Typically used in patchbays.


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Tip of the day #3 - If your patchbay is designed for this type of connector, DO NOT use commercial 1/4" plugs, as they will "spring" the contacts of the patchbay jacks, and can destroy the jacks' switching functions as well.

PostPosted: Wed Aug 02, 2006 4:04 pm
by oddioguy
Same deal, but in a "TS" configuration.

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Same caveats apply as noted in the preceding post.

PostPosted: Wed Aug 02, 2006 4:09 pm
by oddioguy
...and to confuse things further, they make a "Bantam" version. Also known as a "TT" or "tiny telephone", they are .173" in diameter, and are typically used as a patchbay connector due to the saving in space.

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(I'm not going to mention the .205" aviation version. Audio guys don't use 'em)

PostPosted: Wed Aug 02, 2006 4:16 pm
by oddioguy
1/8" (or 3.5mm) plug. Again, available as TS or TRS. Applications are geared more toward consumer devices, but they are used widely on headphones and soundcard breakout cables.

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PostPosted: Thu Aug 03, 2006 8:14 am
by oddioguy
An "RCA", or "phono" plug (not to be confused with a "phone" plug). Typically used on consumer electronics, but also used on S/PDIF cables.

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PostPosted: Thu Aug 03, 2006 9:22 am
by oddioguy
5 pin DIN plug, commonly used for MIDI applications.

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PostPosted: Thu Aug 03, 2006 9:35 am
by oddioguy
Although these are a relative newcomer, Speakon plugs are pretty much the standard for speaker cable termination.

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Tip of the Day - Speakon connectors are available in 2, 4, and 8 pole configurations.

PostPosted: Thu Aug 03, 2006 10:31 am
by weatherstation audio
Banana speaker connector... most pro audio power amps of ther past and today have these type of connections, but it seems that the speakon format is slowly taking over.

The bump on the left of this Banana cable connector is the negative connection... in ease of indentifying in the dark, perhaps ?

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And the mated version on the power amp chassis.

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PostPosted: Thu Aug 03, 2006 11:04 am
by oddioguy
weatherstation audio wrote:Banana speaker connector... most pro audio power amps of ther past and today have these type of connections, but it seems that the speakon format is slowly taking over.

The bump on the left of this Banana cable connector is the negative connection... in ease of indentifying in the dark, perhaps ?

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And the mated version on the power amp chassis.

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Thanx WSA! You just saved me from having to do this one.

PostPosted: Thu Aug 03, 2006 11:08 am
by oddioguy
weatherstation audio wrote:And the mated version on the power amp chassis.

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Technically, what WSA has illustrated here is a 5-way binding post configured for standard 3/4" spacing.
These will accept banana plugs, bare wire, fork terminals, pin terminals, etc.

PostPosted: Fri Aug 04, 2006 8:14 am
by oddioguy
If you're Canadian, this is an EDAC connector. Americans know it as Elco.
These are catagorized as "rack and Panel" connectors, and see a lot of action on ADAT machines (remember those?) and patchbays. Where ever you need to terminate a lot of wire in a small space.

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PostPosted: Fri Aug 04, 2006 8:17 am
by oddioguy
Before Speakon, Amphenol EP and AP series connectors were a common sight on pro speaker boxes.

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PostPosted: Fri Aug 04, 2006 8:22 am
by oddioguy
I could do a thesis on military circular connectors. They are used in pro audio where mass termination needs to be fast and idiot proof. Rugged and reliable, they come in a bewildering assortment of sizes and configurations.

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