Looking for a word clock over fibre solution

[klaukholm]

I am trying to find a way to reliably pass dedicated word clock over fibre.

Something that looks like the SSL opticoax, but designed for WC.

[d_fu]

While this may be overkill for your specific needs here, have you considered MADI?


Daniel

[klaukholm]

It is in fact for a madi system.

I have an optical madi cable run of 100m and I want to pass a separate clock over the same optical multicable, but it has to be separate from the madi stream.
One of the madi units requires external clock and incapable of taking sync from the madi stream.

The alternative is a single low loss coax, but I would love to have an all in one solution. If it would also pass midi or USB I would be a very happy customer.

[Teddy Ray]

Optocore GmbH - Optical Digital Fiber based Network System for Audio and Video - Munich

or will the ADI 648 work?

[klaukholm]

I have been looking at those, but pricing is hard to come by. Do you have a pricelist, or a link to a dealer with prices listed?
It seems like it may be on the expensive side.


I am a little worried about the delay it puts on the clock.
I would prefer a zero latency solution if such a thing exists.

As for the RME, I am sceptical of the solidity of clocks extracted from madi.
Interestingly both DAD and SSL require external clocking of their madi/PTHD units which is where I will be using this.

[d_fu]

Kjetil,

some more details would help. What's the device in question that is unable to clock to MADI? Where is it positioned? Isn't there another MADI device nearby in the setup that will clock to MADI and could just exract and feed Word Clock to the XYZ 123? The 648 could, but you may have something else already...

Daniel

[klaukholm]

Master clock will soon be a brainstorm placed by the AD's

2x Euphonix AM713 madi over coax
1x Euphonix MD704 madi over coax
short coax cables
2x ssl opticoax format converters
(or "direct-out" SPLIT.CONVERTER if they can deliver within a few weeks)

100-150m optical madi snake
SSL Delta link + 2x192D interfaces
1.5' digilink cable
HD3

I need a rock solid clock for 96khz operation

Until now, we have been using a DAD for our madi/pt interface and I used the fourth unused strand of our 4way coax snake for dedicated clock.

I am have an inkling that the ssl and the dad are the same design with optical and coax being the only difference.
They both have some unique design features and limitations that are identical, such as the clock issue and the digilink cable length restrictions.

[Teddy Ray]

Originally Posted by klaukholm

I have been looking at those, but pricing is hard to come by. Do you have a pricelist, or a link to a dealer with prices listed?
It seems like it may be on the expensive side.


I am a little worried about the delay it puts on the clock.
I would prefer a zero latency solution if such a thing exists.

As for the RME, I am sceptical of the solidity of clocks extracted from madi.
Interestingly both DAD and SSL require external clocking of their madi/PTHD units which is where I will be using this.

TTS

just type OPTOCORE into the search box at the home page....and a price list will come up

[klaukholm]

Thanks for that, but at $8000 per unit it would cost me 16k.
I was hoping for something in the opticoax pricerange.

[Bixby]

Our RME 648s have been flawless in two years of use. They're fed by a Lucid clock on one end, and feed a Big Ben (only for distribution - we had one and it has the number of outs that we need) on the other end.

[klaukholm]

Like I said in my first post, I am looking for a dedicated clock over optical, not any form of embedded madi clock.
I can do this already by hooking up two euphonix and use them for clock only, but I don't see this as a rock solid option.
The DAD in combination with PT was very finicky with clocking and I expect the ssl to be very similar.

[Bixby]

Hey, sorry to offer my experience re: clocking with the RME 648. Myself, I'd probably try it and see.

Good luck in your search.

[klaukholm]

The issue is that I need far better jitter specs than madi can provide.
Madi jitter is scary high.

[Teddy Ray]

Originally Posted by klaukholm

The issue is that I need far better jitter specs than madi can provide.
Madi jitter is scary high.

you won't find anything cheap..

the optocore and the ADI are the only two that I know of..

[mpdonahue]

Originally Posted by klaukholm

The issue is that I need far better jitter specs than madi can provide.
Madi jitter is scary high.

But to ask a stupid question: Does it actually matter? What we're talking about here is digital interface jitter that has no bearing on the audio quality, not conversion jitter.
Also, any DA worth its salt uses a clock recovery circuit to reshape the incoming clock signal.
I would be far more concerned about the actual clock timing relationships rather than the jitter induced by a MADI transmission link, but that's just me.......

By the way, I think the Direct Out stuff looks great. We already purchased the split-converter and are waiting for its arrival.

All the best,
-mark

[klaukholm]

Mark,
not a stupid question at all!

Can high jitter cause clicks and pops?
That is the main concern I have these days.

As the dad (and seemingly the ssl, but we will see) is incapable of extracting clock from the madi stream, it would seem an odd result of that design choice if one were to extract clock from the madi stream and pass it to the DAD WC.


I have been talking with DAD about it, bit the problem is that they are not the actual designers of the unit (soundscape?)


I will have to to some extensive testing this summer

So far the most viable solution is to bring a coax snake.

[d_fu]

Originally Posted by klaukholm

Can high jitter cause clicks and pops?

Not unless it's higher than a MADI receiver's tolerance. I don't think this will be an issue.

As the dad (and seemingly the ssl, but we will see) is incapable of extracting clock from the madi stream

How so? As long as a device can sync to incoming MADI and then feed this clock to a Word Clock output, that should be all you need, if I'm not mistaken. Which device is the one that won't clock to WCK here?

As for the ADI and jitter (removal), it's got this...


Daniel

[klaukholm]

The dad and probably the ssl will not clock to the madi incoming.
Interesting as it is a madi PT interface.

Every other piece I have will happily clock to madi.

[klaukholm]

It is a bit of a sidebar, but I have been reliably informed about issues with the opticoax under certain conditions.

It is supposedly not happy with 56ch madi, and was not working with certain digico another highend console that needs to remain nameless.

The deltalink also has this problem, but it was solved with a firmware update.

Has anyone here had sucess running 28/56ch madi over the opticoax? (I have one unit coming here, and I will report back to say if it is working or not)
32/64 is not the issue.

I really hope direct out can deliver soon!

[mpdonahue]

We had the same problem with the Sony DMX-R100. It too does not clock to MADI.
This might be a little overkill, but you could also use the Alphalink SX or AX to receive the MADI and generate local clock. As a bonus you would also have local analog conversion. The prices here in the states have dropped pretty dramatically in the past half year. When I last looked the SX was $2900 and the AX was $2600.
Also, I believe that you can still get the iBox 64-MADI-T from Sydec/soundscape directly for $1875. Same MADI implementation as the Alphalink.

***Edit***
The iBox 64-MADI-T also has double speed TDIF which interfaces with the X48 directly. I have seriously thought about a 48 track/96k remote kit with 2 Iboxes, X48 and a SSL MadiExtreme 128 or MX-4. Total cost is somewhere just south of $10k all in including Pyramix Native.
Food for thought.

All the best,
-mark

[LX3]

Originally Posted by klaukholm

2x ssl opticoax format converters
(or "direct-out" SPLIT.CONVERTER if they can deliver within a few weeks)

Hello hello... what's that?

Could that be the bit of kit I've been waiting for? (active optical MADI splitter?)

That makes TWO bits of SSL gear I'm waiting to hear something about

I pretty much concur with Daniel, to my way of thinking, as long as the receiving interface doesn't lose sync with the incoming MADI signal, you should be good. The quality of the audio is determined by the clock quality at the A-D end. Yes, there's jitter like crazy by the time the data ends up as MADI, but that doesn't matter...

...Apart from when it gets reconverted to analog, as the show happens. In which case I would say it depends on the clock handling and PLL setup of the receiving system. I know RME make a big deal of their clock de-jittering in their MADI cards. Not sure what the SSL / PT combination will do. Are you mixing live in PT as well? If you're only capturing audio, and monitoring for your own confidence purposes, then I don't think the jitter issue is anything to worry about.)

All these different MADI manufacturers... It's so frustrating. Even RME seem to be a little behind the curve. Their little MADI router would be a fantastic tool if only it wasn't essentially coax only

[klaukholm]

Originally Posted by LX3

Hello hello... what's that?

Could that be the bit of kit I've been waiting for? (active optical MADI splitter?)

It is made by "direct out" company and should be coming out at the end of this month......
we all have heard that one before.
Nevertheless I just placed an order.
SPLIT.CONVERTER

As for monitoring, I need to have 100% confidence of the sound and the mix in session. It is usually mixed in PT and edited in PMX.
This setup is for movies and videogames only.
The listening is

ADA8 (sometimes euphonix system5 DA)
-
multimax
-
hypex/lipinski L707 plus atc scm20a (two complete 5.0 systems with a shared sub)

(the Prism is actually pretty immune to bad clock)

[LX3]

Ahhh that's close to what I'm looking for, but I'm ideally looking for something that will take one optical input and provide two optical outputs.

But it's very close...! Could be useful, if it's not super-expensive. Thanks for the link.

Re monitoring and clock/D-A quality, if you're monitoring the Prism outputs and you're happy that it is good at dejittering jittery incoming data, then you're in business.

Otherwise you need to get WC out of ProTools somehow (off a 192 maybe, assuming it throws out WC when PT is locked to the DeltaLink - not sure, not a big ProTools guy myself) put it through a clock unit like a Big Ben, and feed the Prism with word from there.

But I suspect that would be overkill.

I get the feeling that any time you try to put clock down an optical cable you tend to get a lot of jitter, whether it's part of a MADI stream or not.

[klaukholm]

Originally Posted by LX3

Ahhh that's close to what I'm looking for, but I'm ideally looking for something that will take one optical input and provide two optical outputs.
.

Look more closely,
you can route any input/output pair to any of the other three so you can achieve what yuu want,
ca 900euros I hve heard

there is a simple splitter out there for optical that is under 300 euros. Is that what you are looking for?

look at the bottom of the pricelist
http://www.madicables.com/docs/Madic...0pricelist.pdf

[LX3]

Originally Posted by klaukholm

Look more closely,
you can route any input/output pair to any of the other three so you can achieve what yuu want

Oh yes, duh, what am I thinking? All these optical connections get duplexed up so often, I forget the "in" doesn't need to be connected to the same device as the "out".

there is a simple splitter out there for optical that is under 300 euros. Is that what you are looking for?

I'm just concerned with these passive optical splits - obviously each branch loses a big chunk of light output, so suddenly all bets are off when it comes to the length of fibre it'll support. (because I want to put the split at the stage end and run two fibres to recording world). But thanks for the link - it's a cute box.

There is a Chinese-made generic multi-mode active repeater you can get, which might do the trick. And it's very affordable. (under $200). I'll investigate more in a few months time when I finish building all the other stuff I'm working on

I'll be fascinated to hear how it's going with your DeltaLink/PT/Prism rig. Hope it's coming along - sounds like a great setup.

[klaukholm]

Paul, I will let you know how things progress as far as solidity is concerned.
I have until september 1st before I will try the new setup. I am very very paranoid and will not use this rig until I know for sure it is rock solid.

[LX3]

I don't blame you. I feel there are a lot more issues to nail down in a complete MADI rig than your average copper and analog system - I'm also battling with similar issues, although I'm in no particular rush to get things together - a few other priorities at the moment. Bits of my system are sitting in boxes waiting for me to get on with it, so I've got all that fun to look forward to.

[klaukholm]

Paul, please use this thread to share your experiences and troubles.

I spent a long time getting my first PT madi setup to work (all coax), only to have to switch to a new rig again.

It is simply harder to troubleshoot when you have so many components and formats compared to my AES based PMX rig.

[0VU]

Originally Posted by LX3

Ahhh that's close to what I'm looking for, but I'm ideally looking for something that will take one optical input and provide two optical outputs.

Which can be done using the RME MADI Bridge (use input 7 or 8 and send to output 7 and 8), and you still have the option of going to/from/amongst copper MADI connections. If you need more optical capability then you can add the six channel RME MADI converter to change the copper MADI connection on the Bridge to/from optical connections.

I have two MADI Bridges and one MADI Converter and they seem to do what it says on the tin. I bought the Bridges, used, for about £600 each and the converter, ex-demo, for £400.

[klaukholm]

Know of any more rme's at those prices?