[sdiy] S/PDIF cable.

[Alex]

Hi,

If you go into the Belden catalog at www.belden.com you will find that
Belden 9729 or 89729 (ProPlex) will work fine for SPDIF or AES.

You can usually by this stuff by the foot from any professional lighting or
electronics store that sells bulk cable. Just get some Neutrik connectors
and make it yourself.  The jack is sheilded and it about 1/4" to 3/8" in
diameter.

This is the same cable used for carrying DMX512 for lighting control
systems.

Hope that helps.


----- Original Message -----
From: "Batz Goodfortune" <batzman at all-electric.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, April 27, 2002 10:36 AM
Subject: Re: [sdiy] S/PDIF cable.


> Y-ellow All.
>          And thanks to everyone for that. Yeah. Sounds like 75ohm coax is
> the go here. I was kinda hoping the 50 would have been suitable simply
> because it's a narrower diameter but it really isn't overly traumatic. I'm
> not exactly spoilt for choice at the moment.
>
> At 09:01 AM 4/27/02 -0700, John L Marshall wrote:
> >Use the 75 ohm coaxial. Do you have RG-59 foam? That would be my first
> >choice.
>
> I always thought RG59 was thinner than this stuff but I don't have much
> choice. The sample I have here doesn't have anything printed on it so it's
> unclear what it is. But it IS 75ohm. It's actually designed as aerial
cable
> but it works OK for video. I have surveillance cameras running on 20
metres
> of the stuff with out any problems.
>
> >Transformers exist to convert from AES/EBU 110 ohm balanced to 75 ohm
> >unbalanced. The unbalanced lines can run long distances.
>
> The problem at that end is that the only option on a Yamaha O1V is a
> 4in/4out AES/EBU podule. I'm not even 100% sure it won't spit the dummy
but
> since S/PDIF is a superset of AES/EBU (logically) and none of the
> extraneous bits will be sent anyway, it should work. And Biphase mark
> doesn't require polarity concerns unless of course there's some
> non-isolated electrical imperative. Which of course, the transformers take
> care of.
>
> The podule has 8 tiny transformers on it, to, as you say, convert balanced
> to unbalanced. But these seem to be entirely isolated at the back end from
> everything so I should be able to connect the coax across the trannies
> ignoring the centre tap and that should work. I hope! The centre taps seem
> to be common grounded so it would be a good idea to leave those alone.
>
> Some of the sources have transformers but the RCA sockets are still
> grounded. Makes no sense to me but there you go. But one in particular has
> no isolation at all so I'll be relying entirely on the transformer in the
> back of the podule for that. The podule apparently takes care of
> synchronization so I don't have to worry about a central word clock
> generator. I have assurances from the supplier but Yamaha's documentation
> is less than clear. They'll hear me shouting abuse at them all the way
over
> in Japan if this is not the case.
>
> Believe it or not it's taken me 2 years to get to this stage. I remember
> discussing how to make a suitable transformer should I need to with Peter
> Ullrich just prior to having to leave the list. Hello Peter if you're out
> there. But it actually took them this long to get back to me with
assurance
> that it will handle asynchronous inputs.
>
> The only other problem I've just realized. The I/O on the back of this
> podule is actually a DB25. That's going to be a fiddley cow of a thing to
> hook coax to. Still, we have to do what we have to do. And I've had to do
> worse. And if it really is unworkable, I guess it wouldn't hurt to run a
> short length of some liter shielded cable out to an RCA socket. Or
> something along those lines.
>
> Anyway thanks all for that. Sounds like a plan.
>
> Be absolutely Icebox.
>
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