Labelling error on diagram in Audio over Internet article

[Drew Stephenson]

A very minor thing, but if I've understood it correctly, I think the text for table 2, T568-B format, has been copied from table one with pins 2 and 6 being swapped over. So the orange cable is labelled green and vice versa.
Or I haven't understood it correctly...

[Hugh Robjohns]

Oooh! I'll check it....

[ef37a]

I will also confess to being rather confused by the diagrams, not least because the orange wires come out yellow to me in my magazine!
I must have made up over a hundred CAT cables and always to the T568-B format and very rarely a "crossover" cable which we rarely need these days.

https://incentre.net/ethernet-cable-col ... g-diagram/

I did some experiments putting audio down CAT many years ago, long before it had been used in any studio context AFAIK although there was a domestic audio system called by the firm I worked for* "Home Network". This used CAT 5/5e solid core UTP cable and carried balanced stereo (on 1&2 and 3&4 IIRC) and 24VDC on 7&8. Speaker were ceiling mounted and the amplifiers attached to their rears.

My own system was to make the solid colour 'hot' and the stripe cold, seemed logical to me but there you go!

Can I also point out that there are two types of CAT cable? Yes, UTP and STP but also solid cored "backbone" cable and stranded patch cable. Folks might think that only patch cable will do but in practice solid core never gave me any trouble and is much cheaper. Certainly for static cabling, to and from a patch bay e.g. solid core is perfectly good. Also note, you are supposed to use a different RJ45 plug for the two types of cable. I have always used whatever plugs I had to hand for the two types and never had a problem. Naturally when making up patch cables in production you must use the correct type.
If you are are going to make you own cables you are strongly advised to get a tester such as the "VCELINK" very cheap. I will find a link if anyone is interested.

*Then RW Data bought by Hellerman Tyton.

Dave.

[Hugh Robjohns]

I think the text for table 2, T568-B format, has been copied from table one with pins 2 and 6 being swapped over. So the orange cable is labelled green and vice versa.

You're quite correct! Apologies. And despite checking it carefully several times, the fault is originally mine and unspotted by anyone else through the production chain.

I award myself Muppet of the Month!

[Matt Houghton]

I award myself Muppet of the Month!

Which one? I'm picturing Dr. Bunsen Honeydew — you sometimes give off that white lab coat aura But I suppose that would that make me your hapless assistant, Beaker?

[Hugh Robjohns]

[Drew Stephenson]

I award myself Muppet of the Month!

Which one? I'm picturing Dr. Bunsen Honeydew — you sometimes give off that white lab coat aura But I suppose that would that make me your hapless assistant, Beaker?

I'd like to see that podcast!

[Matt Houghton]

I award myself Muppet of the Month!

Which one? I'm picturing Dr. Bunsen Honeydew — you sometimes give off that white lab coat aura But I suppose that would that make me your hapless assistant, Beaker?

I'd like to see that podcast!

What can I say? "Meep meep!"

[Watchmaker]

Regardless of the gaffe, this is an article I've been waiting for. All in all an excellent issue. Well done you lot. I assume pics on the website will be updated?

I've only ever put together CAT cables for telecom in buildings and have been curious about the differences in schema amongst manufacturers, so very helpful. I get the draw to proprietary systems and all, but this is one area where I don't buy because of the lack of standardization. Mix and match is a key consideration in this field. Maybe I'm the only one but it seems to me every mfg is losing out on sales with this approach.

[Matt Houghton]

Mix and match is a key consideration in this field. Maybe I'm the only one but it seems to me every mfg is losing out on sales with this approach.

Yes, you'd think so, wouldn't you? I suppose the challenge to overcome in standardisation is who will blink first, in terms of dropping backwards compatibility with their own previous devices.

[Drew Stephenson]

Yes, you'd think so, wouldn't you? I suppose the challenge to overcome in standardisation is who will blink first, in terms of dropping backwards compatibility with their own previous devices.

Some kind of switchable or twin-socket system would be needed but then you're adding additional costs...
Though if you could get the main candidates on a rotary dial and have a converter box that might have a lot of value in a pro's toolkit.

[Wonks]

Though if you could get the main candidates on a rotary dial and have a converter box that might have a lot of value in a pro's toolkit.

You'd really need two rotary dials to make it universal, one for the input format and one for the output format.

But you'd also have to know exactly what format each bit of kit used. Obviously some are listed, but I doubt all are. Agreeing a connection type list and then getting manufacturers to state the type number would help.

[ef37a]

What we need is some enterprising bod to manufacture some small converter boxes. These would have an RJ45 in and out and you tell them what you are converting from and to.

Dave.

[Drew Stephenson]

Though if you could get the main candidates on a rotary dial and have a converter box that might have a lot of value in a pro's toolkit.

You'd really need two rotary dials to make it universal, one for the input format and one for the output format.

That occurred to me afterwards!

But you'd also have to know exactly what format each bit of kit used. Obviously some are listed, but I doubt all are. Agreeing a connection type list and then getting manufacturers to state the type number would help.

You could probably get a fair way just labelling things by manufacturer. But yes, getting manufacturers to state their standards on the box would be useful.

[Hugh Robjohns]

It took a long time for the industry to converge into XLRs for mic connectors, and even longer to settle on pin2 hot.

It was the same with Tascam's db25 connector for 8 balanced analogue and even longer for its use with 4x4 AES3.

I find it immensely frustrating that the AES doesn't actively coordinate a standard when a new interface format emerges. There have been exceptions, but generally the AES Standards Committeet waits until the industry sorts itself out, and then writes a shiny 'standard' like they're an important organisation that knew the best way all along!

AES72 is a(n in)complete joke of a standard, and manufacturers are idiots for not sticking with one of the two existing ethernet standards — at least we'd only have two variants if they had.

[ef37a]

Cluster**** Hugh. I am presently at P400 (of 553) of The Story of The Computer by Stephen J Marshall and am constantly surprised by the amount of company to company cooperation there was and the fact that it seemed easy to bolt a memory system, tape storage device, card reader etc to all the various machines? Quite different from the global audio industry which for a long time seemed to invent a new connector every time it developed a new microphone. I have them for Reslos but recall Grampian had something never seen on anything else and they were all at it.

But then the emerging computer industry was characterised by a lot of clever people changing jobs and setting up companies as often as they changed underwear! There seemed to be very little attempt by the big firms, IBM say to stop these people taking their ideas with them?

Dave.

[Watchmaker]

AES72 is a(n in)complete joke of a standard...

The pinnacle of editing skills.