SPDIF cables to a Patchbay?

[Wayne Stephens]

Hello again to all of you,

I have a question about Digi transfer cables.
I'm sure that I'm not the only that is moving my SPDIF connections
around from machine to machine all of the time.

Is it possible to run these connection thru a standard patchbay without
losing quality of signal?

I have a few of the connections in one already (DAT and CD recorder IO)
I just put a RCA to 1/4" mono adapt. on the cable and run them in an
unbalanced bay and it seems to work without any problems at least to my
old tired ears.
I just was wondering before I bring the rest of them out to the bay
(sound card, mixer, outboard fx units)

Thanks for any insight
Wayne

[Scott Dorsey]

Wayne Stephens > wrote:
>
>I have a question about Digi transfer cables.
>I'm sure that I'm not the only that is moving my SPDIF connections
>around from machine to machine all of the time.
>
>Is it possible to run these connection thru a standard patchbay without
>losing quality of signal?

No, although you can use AES/EBU stuff on a standard 1/4" patchbay and
usually get away with it.

>I have a few of the connections in one already (DAT and CD recorder IO)
>I just put a RCA to 1/4" mono adapt. on the cable and run them in an
>unbalanced bay and it seems to work without any problems at least to my
>old tired ears.
>I just was wondering before I bring the rest of them out to the bay
>(sound card, mixer, outboard fx units)

The safe thing to do is use a 75 ohm patchbay, like a video patchbay.
But you might be able to get away with using something of the wrong
impedance in a noncritical application, but sooner or later you will
find some configuration that won't work. As long as the clock locks
up, you can get away with murder but just a little bit more and all
hell breaks loose. Best to be safe and use the right connectors.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[nmm]

On Wed, Nov 19, 2003 11:27 AM, Scott Dorsey >
wrote:
>Wayne Stephens > wrote:
>>
>>I have a question about Digi transfer cables.
>>I'm sure that I'm not the only that is moving my SPDIF
>connections
>>around from machine to machine all of the time.
>>
>>Is it possible to run these connection thru a standard
>patchbay without
>>losing quality of signal?
>
>No, although you can use AES/EBU stuff on a standard 1/4"
>patchbay and
>usually get away with it.


But digital is either there or it isn't. I've seen digital AES/EBU run on
110 Ohm shielded pair , and 75 Ohm Coax. Ward Beck systems make a whole
array of Distribution amps, and impedance transformers for AES/ EBU.
All the new Sony machines.. well since Beta SX have their outputs on a BNC
( ie 75 Ohm Coax)



>
>>I have a few of the connections in one already (DAT and CD
>recorder IO)
>>I just put a RCA to 1/4" mono adapt. on the cable and run
>them in an
>>unbalanced bay and it seems to work without any problems
>at least to my
>>old tired ears.

If it's working it's working .. The thing with digital is when it;s not
working .. It;s not there.. There isn't a signal degradation.. It's
numerical information..



>>I just was wondering before I bring the rest of them out
>to the bay
>>(sound card, mixer, outboard fx units)
>
>The safe thing to do is use a 75 ohm patchbay, like a video
>patchbay.
>But you might be able to get away with using something of
>the wrong
>impedance in a noncritical application, but sooner or later
>you will
>find some configuration that won't work. As long as the
>clock locks
>up, you can get away with murder but just a little bit more
>and all
>hell breaks loose. Best to be safe and use the right
>connectors.
>--scott
>

Yeah a Video patch bay would be the best way to go for this.. They are
expensive! ( compared to audio patch bays )

as long as everything is the same format .. and you are getting signal it
will work.

Another option might be to convert everything to AES/EBU.. I've heard
there are small passive boxes to do this.. but haven't seen them.

[Mike Rivers]

In article > writes:

> Is it possible to run these connection thru a standard patchbay without
> losing quality of signal?

Maybe, but you don't want to mix them with analog signals on the same
patchbay. Too much chance of connecting the wrong thing together (with
consequences potentially ranging from electronic damage to really loud
and unpleasant noises) plus leakage and different grounds.

Why not make up or find an RCA patch panel? Those aren't the greatest
connectors, but it will keep you away from mispatching dangers, and
may possibly give better signal integrity. Actually, probably even
better would be a BNC patch panel or a video patch panel salvaged from
the junkpile of a TV station.





--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Kurt Albershardt]

Mike Rivers wrote:
>
> even
> better would be a BNC patch panel or a video patch panel salvaged from
> the junkpile of a TV station.


Yes, yes, yes. Trompeter and ADC both make excellent ones, and you can
get them now for a fraction of the price you'd have paid new.

BTW, the full sized Trompeter jacks (and probably the ADC's as well)
will fit into a Switchcraft ¼" patch panel so you can mix video (or
S/PDIF) and audio in the same panel. We used to do this all the time
for small editing systems.

[Wayne Stephens]

Thanks for a reply Mike
Any problems using BNC to RCA apapts. as long as you stay with the 75
ohm digi cables? Or will I have to buy RCA to BNC cables?

Mike Rivers wrote:
> In article > writes:
>
>
>>Is it possible to run these connection thru a standard patchbay without
>>losing quality of signal?
>
>
> Maybe, but you don't want to mix them with analog signals on the same
> patchbay. Too much chance of connecting the wrong thing together (with
> consequences potentially ranging from electronic damage to really loud
> and unpleasant noises) plus leakage and different grounds.
>
> Why not make up or find an RCA patch panel? Those aren't the greatest
> connectors, but it will keep you away from mispatching dangers, and
> may possibly give better signal integrity. Actually, probably even
> better would be a BNC patch panel or a video patch panel salvaged from
> the junkpile of a TV station.
>
>
>
>
>
> --
> I'm really Mike Rivers - )
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

[ar3a]

"nmm" > wrote in message ...
> On Wed, Nov 19, 2003 11:27 AM, Scott Dorsey >
> wrote:
> >Wayne Stephens > wrote:
> >>
> >>I have a question about Digi transfer cables.
> >>I'm sure that I'm not the only that is moving my SPDIF
> >connections
> >>around from machine to machine all of the time.
> >>
> >>Is it possible to run these connection thru a standard
> >patchbay without
> >>losing quality of signal?
> >
> >No, although you can use AES/EBU stuff on a standard 1/4"
> >patchbay and
> >usually get away with it.
>
>
> But digital is either there or it isn't.

Or it is...then isn't. Then is again...then isn't again. Then is...you get
the idea. Usually, the "isn't" is when there's a client in front of you and
you're trying to perform a critical transfer.

[flint]

This might be helpful:
http://student.math.hr/~sklaic/electronics/

- Flint


"ar3a" > wrote in message
...
>
> "nmm" > wrote in message
...
> > On Wed, Nov 19, 2003 11:27 AM, Scott Dorsey >
> > wrote:
> > >Wayne Stephens > wrote:
> > >>
> > >>I have a question about Digi transfer cables.
> > >>I'm sure that I'm not the only that is moving my SPDIF
> > >connections
> > >>around from machine to machine all of the time.
> > >>
> > >>Is it possible to run these connection thru a standard
> > >patchbay without
> > >>losing quality of signal?
> > >
> > >No, although you can use AES/EBU stuff on a standard 1/4"
> > >patchbay and
> > >usually get away with it.
> >
> >
> > But digital is either there or it isn't.
>
> Or it is...then isn't. Then is again...then isn't again. Then is...you
get
> the idea. Usually, the "isn't" is when there's a client in front of you
and
> you're trying to perform a critical transfer.
>
>

[nmm]

On Wed, Nov 19, 2003 5:58 PM, ar3a > wrote:
>
>"nmm" > wrote in message news:BBE114AE-
...
>> On Wed, Nov 19, 2003 11:27 AM, Scott Dorsey <
>
>> wrote:
>> >Wayne Stephens > wrote:
>> >>
>> >>Is it possible to run these connection thru a standard
>> >patchbay without
>> >>losing quality of signal?
>> >
>> >No, although you can use AES/EBU stuff on a standard 1/
>4"
>> >patchbay and
>> >usually get away with it.
>>
>>
>> But digital is either there or it isn't.
>
>Or it is...then isn't. Then is again...then isn't again.
>Then is...you get
>the idea. Usually, the "isn't" is when there's a client in
>front of you and
>you're trying to perform a critical transfer.
>

That sounds more like an intermitant contact/ short than problem with the
signal.

Digital signals don't degrade... that's the advantage.. when i type
<<010101010101010101>>

You read <<010101010101010101>>

Yes. when things do F$#@$% Up it is usually in front of paying clients.

If he is getting signal through a patch bay without loss of data.. then it
is working. It won't degrade, that is not possible.

.. Someone else mentioned that you should be more worried about what it
might do analogue signals through the same patch bay.. that is valid!

[Robin]

If it's RCA spidif/Toslink you're patching...

Check out the M-Audio Digipatch.

Very handy...

HTH,

Robin Farrell
JuliRob Productions

[Mike Rivers]

In article > writes:

> Any problems using BNC to RCA apapts. as long as you stay with the 75
> ohm digi cables? Or will I have to buy RCA to BNC cables?

No, adapters work fine, but RCA-BNC cables aren't hard to find
(Markertek has them) and it removes one potential point of failure. It
also probably costs less to buy 75 ohm RCA-BNC cables from a place
like Markertek than to get adapters and RCA cables from Radio Shack.



--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Justin Ulysses Morse]

Go to Radio Shack and buy a video switch box. It'll have a bunch of
RCA inputs and one RCA output. Since it's intended for video, it'll be
"75 ohm" if it's any good. If it's a piece of ****, it'll have bigger
problems than its characteristic impedance. But a good one will cost
less than a patchbay.

And no, you don't want to connect SPDIF to your existing audio patchbay
in hopes of saving money/space/hassle.

ulysses


In article >, Wayne Stephens
> wrote:

> Hello again to all of you,
>
> I have a question about Digi transfer cables.
> I'm sure that I'm not the only that is moving my SPDIF connections
> around from machine to machine all of the time.
>
> Is it possible to run these connection thru a standard patchbay without
> losing quality of signal?
>
> I have a few of the connections in one already (DAT and CD recorder IO)
> I just put a RCA to 1/4" mono adapt. on the cable and run them in an
> unbalanced bay and it seems to work without any problems at least to my
> old tired ears.
> I just was wondering before I bring the rest of them out to the bay
> (sound card, mixer, outboard fx units)
>
> Thanks for any insight
> Wayne
>

[nmm]

On Wed, Nov 19, 2003 9:10 PM, Mike Rivers >
wrote:
>
>In article >
>writes:
>
>> Any problems using BNC to RCA apapts. as long as you stay
>with the 75
>> ohm digi cables? Or will I have to buy RCA to BNC cables?
>
>No, adapters work fine, but RCA-BNC cables aren't hard to
>find
>(Markertek has them) and it removes one potential point of
>failure. It
>also probably costs less to buy 75 ohm RCA-BNC cables from
>a place
>like Markertek than to get adapters and RCA cables from
>Radio Shack.
>

If you tell me the lengths you need i have a lot of Belden 1505a that i
can put BNC(s) on.

takeout the "I" to respond

[Ralf Köster]

[nmm wrote:]
> Digital signals don't degrade... that's the advantage.. when i type=20
> <<010101010101010101>>
[...]
> Someone else mentioned that you should be more worried about what it
> might do analogue signals through the same patch bay.. that is valid!


But SPDIF or whatever cable doesn't transport numbers! It transports an =
electrical signal aka "Volt". And these signal can be above or below a =
certain threshold (in the SPDIF receiver). Therefore the problem with =
interference of digital signals in a patch bay is the same as with =
analog signals, although not as obvious.

....Ralf