Necessity of word clock when connecting to AD/DA converters

[weighbor]

ok, i'm some guy trying to do writing, recording, mixing on LE hopefully to a high high standard (all sorts of stuff!)
I love protools as a DAW. :-0 bottomline. mostly software interface, workflow.. software parts and how it sounds kinda neutral and the fact that it is easy to take it to many studios just the way it is
but somehow i find the ad/da's of the LE-associated hardware (although i know there are people who can mix brilliantly on even internal computer speakers!... and i really want to grow like that!.. am trying.. tho) not brilliant / comfortable enough when it comes to mixing. and also i found it slightly more difficult to find the virtual instrument on RTAS platform.. but still i love protools.. don't know why.. but somehow it makes things easier for me work very fastly effortlessly and allow me to try, edit so many takes swiftly midi/wave wise and focus more on music i guess in my case.

the thing is..
i want to be able to get a decent external ad/da along with a dongle that'll allow me to run either PT M-POWERED or PTLE and both logic at the same time.. (i like programming, editing, arranging in protools so much i even use logic purely as a sampler with the internal IAC midi bus going on)

and i recently downgraded from MBOX 2 pro to MBOX 1 in order to add to the budget for both preamp and ad/da solutions..

my current inventory

sm 58 / 57
ISA 220
MBOX 1

so let's say if i were to purchase ROSETTA 200. which is an apogee produce ad/da converter that has both spdif and wordclock I/Os.

but on the mbox1 it has SPDIF I/O but not word clock (BNC?) I/Os unlike mBOX2 pro which i just sold (:'()...

so.. i am worried about how much error / jitter or damage it would cause if i were to directly connect my future ad/da into an interface that only has s/pdif but not word clocks with them (something like mbox1, mbox2, digi002 or transit... etc)...

or should i consider getting something like firewire1814 (by m-audio)? because then i will be able to have both S/PDIF and WORD CLOK I/Os and will still be able to run PTLE and LOGIC as well?!! i'd like to know whether this could work swiftly enough.. (because i think i saw some articles where someone managed to pull it off like this..) or should i revert back to mbox 2 pro..

i don't know how to call it but i wasn't too pleased with the medium high and high end (frequency detail wise) with the mbox-related hardwares.. anyone with similar views on this?

i even considered getting mix plus system to get out of this dilemma but i think it'd be too much to handle for me i think.. getting a new desktop and all..

so in short, my questions are

the chain will be something like

mic -> channel strip -> apogee rosetta 200 a/d -> either PTLE DIGI hardware or PT M-powered M audio hardware -> apogee rosetta 200 d/a -> speakers!

1. if i were to connect an external ad/da to a LE or M-powered hardware how necessary is it (quality-wise) to get an interface that has both S/PDIF options along with WORD CLOCK?

(if it is ok, inside the PTLE or PT M-POWERED has clock source option.. is it ok to set them to just s/pdif? )

2. OPTICAL S/PDIF VS COAXIAL S/PDIF .. i heard that optical option is more beneficial in terms of lossless aspect of transmission.. then again how different are the two (SOUND QUALITY/RISK WISE) for connecting to an external ad/da?

i'd be more than happy if word clock isn't that neccessary i could just use my mbox1, isa220 with some integrated ad/da like rosetta !! blerg!! so i could record, mix, produce more properly / seriously :)

have a nice day folks!!

[flommer]

Mbox 1 is a bad call. It is no longer supported - EOSS - last PT version is 8.0.1

Word clock connections are only necessary when using multiple input A/d's (to use the spdif and optical inputs on a 003 at the same time with 2 different A/d converters, for example) or other more complicated scenarios.

For Rosetta to Mbox the sync will be established via the spdif signal itself, no WC needed

[Dism]

Originally Posted by weighbor

and i recently downgraded from MBOX 2 pro to MBOX 1 in order to add to the budget for both preamp and ad/da solutions..

I don't mean to rain on your parade... but you will probably discover very quickly that this was a bad idea.

Aside from the lack of hardware options available on it, the MBox 1 has been discontinued and will not be compatible with any version of Pro Tools after 8.0.1.

Now, as far as your original questions...

An external AD/DA can make a pretty significant difference. The Rosetta series is a great choice, and a popular one at that. Pro Tools LE can accept a clock source via S/PDIF, ADAT and BNC, and will clock via the same source as the audio. Meaning, you can track via ADAT or S/PDIF and clock from the same source. A good AD/DA will also do the clocking for you, so you don't need another separate clock unless you are doing multiple AD/DA conversions.

I'm not sure how much it really matters as far as S/PDIF clocking vs. BNC, but a good clock can make a huge impact on your recording quality.

If I might make a personal suggestion, the API A2D is both a great preamp, AND a great AD/DA converter, with S/PDIF outputs that leaves your analog inputs free. One of the best solutions for the price.

[nst7]

I don't know about this stuff as much as other people, so hopefully they will offer help. But I can tell you something that might be of interest. I've been looking at getting an Apogee Ensemble to use with my 003R for the same reasons you want to use better conversion. When I called Apogee tech support with some presales questions, we were talking about clocking with the Apogee, which has word clock. He mentioned that the general consensus from people using it in this way, was that you could just use the Ensemble as the master clock using either spidf or adat (depending on how you were using it), and that it actually sounded better this way than by doing it through the word clock cables. So this may apply in your situation, in that even though you don't have a word clock connection, it may not be a big deal. And according to the tech support guy, the Ensemble uses the same clock as the Rosetta's, so the same principle may apply.

Another option to look into would be to get a 003R, or a used 002R and have it modified by Black Lion Audio. They improve many things, including the conversion and the clock. It might be a good overall value for you. You may even be able to trade in your Mbox to Digi for a 003R and get a good deal including Music Toolkit or something.

[weighbor]

aha!

so to sum it up,

DESPITE THE ABSENCE OF WORD CLOCK CABLE connections, WORD CLOCK information is INCLUDED in either S/PDIF cable connection or ADAT LIGHTPIPE cable connection and since the quality word clock source will be provided by A/D device (it being a master source of all the stuff).. i shouldn't worry about it ?

just one more question to add

there exists two types of S/PDIF cables for connection

one being COAXIAL S/PDIF
one being OPTICAL S/PDIF

is there much difference in terms of quality / risk / sound quality / precision / durability of digital data and word clock data ... blah blah blah between the two mediums? or is it un-noticable as long as the environment and setting is calibrated?

oh, and as for the downgrading to mbox 1 being a bad call >_< i sort of agree with that.. a lil regretful !
but i am still deliberately (even though i have leopard and snow leopard installers) swimming in tiger domain so it won't be much of a concern for me for a bit.. i wish i were just more dexterous enough to find and use rtas instruments more swiftly than the logic ones.. but i guess focus on music and sound & creativity that matters!

oh, and WHAT ARE M-POWERED PROTOOLS like compared to PT LE DAW performance & precision wise? because i am not concerned about hardware in terms of a/d d/a quality but more in terms of precision and quality in hardware and software performance when it comes to DD conversion, being an audio interface, and also being a DAW

cheers for swift and satisfactory response guys!!

[BRH]

Get the option card for your ISA 220 and use that to clock your Mbox via SPDIF coaxial.

[weighbor]

Originally Posted by BRH

Get the option card for your ISA 220 and use that to clock your Mbox via SPDIF coaxial.

cheers for suggestion.

funnily enough, i was considering that too.. (budget-wise to figure out a way to not buy unneccessary ad so that i can only bother buying an additional dac and speakers?)

does the option adc card provide decent enough conversion quality? compared to.. say apogee sort of range?
oh , and , does it also provide stable word clock?

:-0 then i could really splurge and get lavry dac or something.. (although if i were able to splurge(which isn't that much amount actually tho.. but anyways), i'd do it to a/d more than d/a)

cheers for the help!

[flommer]

Originally Posted by weighbor

DESPITE THE ABSENCE OF WORD CLOCK CABLE connections, WORD CLOCK information is INCLUDED in either S/PDIF cable connection or ADAT LIGHTPIPE cable connection and since the quality word clock source will be provided by A/D device (it being a master source of all the stuff).. i shouldn't worry about it ?

Yes, the sync/clock info is a part of the spdif or adat data stream.

When there are 2 A/D converters, there are essentially 2 sources for the sync signal.. there can only be one master clock, so the 2nd A/d gets sync'd to the first and the 003 (in that scenario) can take it's sync from either

[BRH]

Of course Apogee is better.... 3 times the $.
For all practical purposes you will not hear a difference... the Focusrite card is really good.
There will be more audible difference in your recording technic.

[Top Jimmy]

Originally Posted by weighbor

DESPITE THE ABSENCE OF WORD CLOCK CABLE connections, WORD CLOCK information is INCLUDED in either S/PDIF cable connection or ADAT LIGHTPIPE cable connection and since the quality word clock source will be provided by A/D device (it being a master source of all the stuff).. i shouldn't worry about it ?

just one more question to add

there exists two types of S/PDIF cables for connection

one being COAXIAL S/PDIF
one being OPTICAL S/PDIF

is there much difference in terms of quality / risk / sound quality / precision / durability of digital data and word clock data ... blah blah blah between the two mediums? or is it un-noticable as long as the environment and setting is calibrated?

Technically, the S/PDIF connection doesn't carry word. Instead, the data is biphase encoded, which is a method of embedding the clock within the data stream itself.

As far as quality, stick with the coaxial S/PDIF with the appropriate 75Ω cable. Optical on the Toslink format usually has more jitter. While this doesn't affect the quality of the data transmitted over the interface, it does affect the D/A clock and the clocking of any A/D conversion happening on the slaved device.