Fireface 8-channel optical ADAT to 8 individual optical SP..

[Guest]

Archived from groups: rec.audio.pro (More info?)

I don't even know how dumb a question this is, but here goes...!

I recently upgraded my system with an RME Fireface. The Fireface has
two optical ADAT I/Os, each of which can support four stereo pairs of
I/O.

Unless you have a device that can distribute those 16 channels, the
actual number of available digital I/O available on the Fireface in
its default state is two: one coaxial and one optical (ADAT2 can be
transformed through software into a single SPDIF optical pair; ADAT1
would then simply go unused).

I'm thinking it might be pleasant to have more than that available--so
that perhaps I could keep several boxes purely in the digital domain.

So that would mean a device or box with a similar ADAT connection
that could distribute the signal into 8 independent optical SPDIFs for
each.

I wish I knew digital audio better. Maybe that's simply technically
impossible.

Strangely, after a ton of searching on the web, the only thing I can
turn up that might be useful is a Behringer DDX3216 with the
appropriate ADAT and SPDIF cards attached. I've been lurking on this
group for enough years to know the general concensus on the
quality/ethics of Behringer, but--barring that--would this be a
possible solution? It's still a little overkill for me, all I want is
the distribution, I really don't need the rest of the mixer functions.
Is there something more appropriate to this purpose?

Anyway, I'd appreciate any insights. Please feel free to correct any
of the above if my elementary understanding is completely wrong.

Thank you!

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Hi,

>
> Unless you have a device that can distribute those 16 channels, the
> actual number of available digital I/O available on the Fireface in
> its default state is two: one coaxial and one optical (ADAT2 can be
> transformed through software into a single SPDIF optical pair;

There is no transformation. The second optical simply switches to SPDIF
mode.

> ADAT1
> would then simply go unused).

No, there's only one SPDIF I/O. It can be set to either optical or
coaxial in, and the same signal can be played back on both the optical
and coax output (not independently).

>
> So that would mean a device or box with a similar ADAT connection
> that could distribute the signal into 8 independent optical SPDIFs for
> each.

The ADI-4DD converts 1 ADAT to 4 AES/EBU or SPDIF, but only XLR or coax,
not optical:
http://www.rme-audio.com/english/adi/adi4dd.htm


Daniel

 

[Guest]

Archived from groups: rec.audio.pro (More info?)

Daniel (and whoever else contributes)--

Thanks very much for the reply. Clearly, I'm not that knowledgeable
about digital I/O. Your reply was very clarifying and made it easier
for me to understand the manual. The Fireface is a superb device and
I want to make sure I'm getting the most out of it.

May I ask other clarifying questions about the Fireface/ADI-4DD
combination?

Let's say I want to add some FX or processing devices to my Fireface
via the ADI-4DD that could allow me to work completely in the digital
domain. Also (for this example), I want to use the recommended sample
split mode to achieve 96 kHz, which means both ADAT1 and ADAT2 will be
required.

Such devices have both digital ins and outs. Since we have now gone
from 16 potential channels (8 stereo pairs), to 4 stereo pairs (to
achieve 96 kHz), and each device has both digital ins and outs, the
actual practical number of digital devices I can add to such a setup
is 2. Is that right?

However, I have noticed that almost all of the devices I'm considering
(in my price and expertise range) have sampling frequencies of 44.1
kHz and 48 kHz. Could I not instead add one ADI-4DD, using only ADAT1
to drive two devices at these frequencies, and later add another
ADI-4DD using ADAT2 allowing me to use two additional devices? Can
two ADI-4DDs run simultaneously from the Fireface?

(I know that some devices, like synth modules, have only one digital
port and so the actual number of devices in such a setup could be
potentially larger than 4).

Finally, because these units tend to have the RCA phono SPDIF
connectors, I need to set the ADI-4DD to consumer mode and find
XLR->RCA adaptors for the breakout cable. Is that reasonable and
right?

Thanks for any insights!



On Sat, 22 Jan 2005 15:32:51 +0100, Daniel Fuchs
<dfuchs@stud.uni-goettingen.de> wrote:

>Hi,
>
>>
>> Unless you have a device that can distribute those 16 channels, the
>> actual number of available digital I/O available on the Fireface in
>> its default state is two: one coaxial and one optical (ADAT2 can be
>> transformed through software into a single SPDIF optical pair;
>
>There is no transformation. The second optical simply switches to SPDIF
>mode.
>
>> ADAT1
>> would then simply go unused).
>
>No, there's only one SPDIF I/O. It can be set to either optical or
>coaxial in, and the same signal can be played back on both the optical
>and coax output (not independently).
>
>>
>> So that would mean a device or box with a similar ADAT connection
>> that could distribute the signal into 8 independent optical SPDIFs for
>> each.
>
>The ADI-4DD converts 1 ADAT to 4 AES/EBU or SPDIF, but only XLR or coax,
>not optical:
>http://www.rme-audio.com/english/adi/adi4dd.htm
>
>
>Daniel