OT: Word Clock and a newbie

[Beel]

Hey,
I´ve come to a point where I guess I need to know a bit more (in my case more means more than nothing) about World Clock syncing.
I have 3 pieces of gear with World Clock jacks: a Yamaha 01R96 mixer, a Akai Z8 and an old AD/DA-to-ADAT Converter a Creamware A-16.
My question is what to do regarding the World Clock thing. What should be Master? Shall I leave it alone and not connect them? Should I buy an external clock? AND... what the heck is World Clock actually doing. I´m sorry if thats a dumb question. I´m lost and have no clue.
Thanx in advance for any helpful soul.

Holger

[killerbobjr]

Word clock is a synchronization method. If you have word clock inputs on your mixer or sound card or rack gear, you can use a master clock source to synchronize everything. This is necessary because every internal crystal used in digital products varies slightly in frequency, and when you connect all these products together via digital connections (lightpipe, S/PDIF, etc.), you get pops and clicks in the audio stream when the gear adjusts itself trying to synchronize with the digital stream.

Not all master word clock generators are alike. The most important specification is how much jitter it produces. Pick the piece of gear you have that has the lowest jitter spec and slave all your other gear to that. You will need BNC type cables and can use \"T\" connectors on the slave devices to daisy-chain all your word clock inputs. Then select \"Word Clock\" on each piece of gear as the syncronization source, except for your gear acting as the master clock. Set that one to internal synchronization.

[Beel]

Thank you so much Killerbobjr ! Now I finally understand it. I knew it is a sync thing but I never figured out what exactly is synced by World Clock.
Thanks again!

Holger

[PeterRoos]

Hi Holger, it\'s Word clock, not world clock images/icons/wink.gif

It is about aligning data \"words\", not syncing with GMT using some atom clock images/icons/grin.gif

just kidding, take care
Peter

[Beel]

Hi Peter,
oh boy... all those manuals, on every page at least 10 times and I even wasn\'t able to READ it right... ok, now you all understand why I have had problems figuring out whats the deal with WORD Clock. images/icons/frown.gif
Now I know why I wasn´t able to find useful information on the net, goggle returned just stuff about time-zones etc... lol.
Hey, its just me. Not all germans are that dumb.
Thanks Peter for correcting me. Better here than in a situation even more embarrassing images/icons/wink.gif

Holger

[Cool7s_Dad]

killerbobjr posts some great info here about word clock. He neglected to mention a couple of critical items, though. Be sure you get 75ohm BNC cables and connectors. (BNC stands for Bayonet Nut Connector... I have no idea where *that* comes from... and originated with the old 10-base-2 networking systems... seems that audio is always stuck in the past). For quite some time, 75ohm was hard to find (it\'s also referred to as RG59 cable) because it was supplanted by the RG6 cable adopted as a standard for NTSC video signals... standard cable-TV fare.

I\'ve had good luck finding 75ohm RG59 cable at my local Altex Electronics store. You can also order this on the web at www.altex.com (\"http://www.altex.com\") preconfigured with the BNC connectors. They also have the T connectors and terminators very cheap there.

One other *critical* item: Be sure to terminate the last device in the daisy-chain with a 75ohm BNC terminator. It\'s a little \"cap\" that plugs into the other side of the T connector on the last device. Without this, your word clock sync will not work right and you\'ll have the dickens figuring out why.

How do I know all this? Am I one smart dude? Not really. I\'m getting this straight from my RME ADI8DD manual. When I rebuilt my studio these last few weeks, I simply followed exactly what they recommended and it has worked GREAT! The people at RME really know their stuff!

Hope this helps.

TM

[Cool7s_Dad]

One more thing. Be sure to set the sync source to \"external\" on all devices except the first one in the chain that originates the sync signal.

TM

[Cool7s_Dad]

Sorry to keep chiming in, but on the subject of digital sync and RME and ADI8DD\'s, I thought it might be useful to mention that the ADI8DD is a KILLER device. I have a POD Pro, a Proteus 2000, a recording computer with a MOTU 2408mkIII and a Gig computer with an RME Hammerfall 9652 in it. I was having a *very* hard time with the digital outs on all this gear. Clicks and pops and grinds and garbage constantly. The main culprit was the Proteus 2000 which outputs only at 44.1khz, while everything else was at 48khz.

I got the ADI8DD Digital Interface from RME and it killed the jitter and the clicks and pops. It\'s an expensive little thing, but it works exactly as advertised. The Proteus 2000 doesn\'t even have a word clock input, but the ADI8DD manages to sync it up and do pristine real time sample rate conversion to 48khz. I highly recommend this device if you are having trouble with digital devices that you can\'t sync up. Again, at $900, it\'s not for everyone, but if you need it, it will definitely do the job.

TM

[Beel]

Cool7s_Dad,
thank you for your detailed info. Indeed you sound like a really smart guy :-)
As for the BNC stuff, I know it pretty well. I´ve been in the computer business for 8 years now. The problem as you mentioned is the 75 Ohm thing. I´ve plenty of 50 Ohm cables and terminators, but 75 Ohm is hard to get.
Actually I´ve still a few problems with the my A-16 and my Yamaha 01R96 and I believe the 75 Ohm is the reason. I have not set termination at all because of the lack of 75 Ohm terminators. Damn, I guess I have to take a look around for the 75 Ohm stuff.
Thank you all for your help !!!

Holger

[Sam]

For word clock I use 75 ohm video cables from these guys:

http://www.svideo.com/bnc2bnc.html (\"http://www.svideo.com/bnc2bnc.html\")

Good prices & works well, IIRC the \"cheap\" stuff uses Mogami video cable which is great.

I bet you can also get rg-59\'s at radio shack.

I never had good success daisy chaining clocks with T\'s. My life got much easier when I got a Mutec clock generator (8 clock outs), though I do have a rather complex setup with 9 lightpipe cables. Mutecs are hard to find in the US but there are alternatives. (Try Google groups on \"wordclock distributor OR distribution\") They\'re a bit dear for gear that doesn\'t make noise, but as a consolation a good clock makes everything else you own sound better. (If you\'re sensitive, dare I say startlingly so?)

[Beel]

Hey Sam,

Thanks for the reply. Right now I do daisy chain and it´s been a pain because of the sync-trouble I have. So I´m considering to buy an external word clock devise. I don´t have that much digital connections like you have right now, but I am planing at least to buy a decent soundcard with ADAT in the near future.
Here in Germany it´s pretty easy to get the Mutec stuff. Do you use the Mutec Smart Clock or do you use the Word Clock Distributor and use one piece of your gear as master?
One other thing, can you actually hear the difference between a good word clock generator and in my case a digital mixer set to master? I don´t mean the obvious klicks ´n pops...
And again to all, thanks for the info and the patience you have :-)

Holger

[Sam]

Hi Holger,

I have everything slaved to a Mutec Smart Clock. It eliminated problems with pops.

I haven\'t A/B\'d my sound with & without it, so I will be the first to admit that the following opinion is unscientific, but I had no expectation of sonic improvement other than pop elimination, & I didn\'t have a bad click problem before; I had a few clock configurations I would futz between & could usually get things working ok without too much trouble. Still from the moment I wired it up, my impression was, \"whoa, that\'s not subtle.\" I had good sound before, but it feels like new gear to me now, with that magic \"expensive\" sheen.

I had heard this from others & not understood it, it sounded like religion to me (still does!) You won\'t hear it if you don\'t have trained ears, & I expect that the difference only appears in the monitoring chain; other than the lack of sync problems I don\'t expect that there\'s a recorded difference. But I do feel strongly about this gear, as in, \"you can take my mutec - when you can pry it from my cold dead fingers!\"

cheers,
-sam

[Beel]

Originally posted by Sam:
But I do feel strongly about this gear, as in, \"you can take my mutec - when you can pry it from my cold dead fingers!\"
<font size=\"2\" face=\"Verdana, Arial\">That sounds promising! images/icons/grin.gif
I think I´ll go for it as soon as possible to get rid of the sync problems and maybe to be able to experience the \"religion\" of improved sound.
You´ve been very helpful! Thanks a bunch.

All the best
Holger