Do I need a synchronizer?

alsound2 · Post by **alsound2** » Sat Dec 08, 2007 4:59 pm

Hello everybody
Recently I've added some new digital units to my studio setup and I'd like to know how to handle the digital sync issue.
These are my list of the digital units:

- MOTU 2408mkIII (on MAC)
- MOTU 828 MKII (on MAC)
- Creamware PULSARII (on PC)
- Presonus DIGIMAX LT
- Yamaha 01V
- Lexicon MPX200 and Lexicon MPX500 (connected to the CW PulsarII via spdif)

My intention was to buy a second hand MOTU Digital Timepiece and use it as a Master and everything else as Slave- Since MOTU DT has got only 1 BNC out connection I think I'd need a BNC word clock distribution amplifier...(every unit listed has got the bnc plug, except Yamaha 01v (mixer) and the Lexicons).
What would you do to assure a nice sync between units? Do you think I need a synchronizer? Or may I daisy chain every unit?
Another thing...Apogee BIG BEN has got more than one BNC out connection, so is it better to buy that one than buying MOTU DT+distribution amplifier?
Thank you!
Stefano

stephen1212b · Post by **stephen1212b** » Sat Dec 08, 2007 11:08 pm

To my knowledge the digital timepiece has never been noted for its great clock. It is very capable but not really what you need. The Big Ben would be a better choice or any other quality master word clock. I use an old Aardsync. Everything that can slaves to the master clock. I assume you will create an aggregate device to include the 01V. Make certain it is slaving to the 2408 mk 3 and the 2408 mk 3 will slave to external word-clock. The lexicon gear automatically slaves to its digital input and the output will therefor be in sync. You are limited to 44.1 K or 48 K sample rates on some of the gear and all of the gear needs to be set to the same sample rate and match the master word-clock sample rate. Try not to loop the clock signal from device to device, but run a separate line to each. You might also have to investigate 75 ohm termination that should be on for every device. If memory serves the 828 mk2 may need an external T adapter with an external 75 ohm termination plug.

alsound2 · Post by **alsound2** » Sun Dec 09, 2007 5:44 am

Thanks Stephen for your complete answer

I'd have a couple of questions:

1) Since Yamaha 01V doesn't have WordClock input as BNC, my idea was to sync it via spdif from Big Ben... so the final situation would be:
BIGBEN as MASTER, everything else as SLAVE
BNC cables from BigBen's wordclock outs to MOTU and creamware interfaces+SPDIF cable from BigBen's spdif out to Yamaha 01V's spdif in. Is it a weird supposition?

2) Thanks for the 828mkII tip, I will check it on the manual. Would I have to plug the T adapter and the external 75ohm termination plug to the Word clock in of the MOTU or in Word Clock out of the Big Ben?
Maybe..the T adapter in the BigBen's out and the 75ohm termin. plug in the 828's in?

Thanks a lot Stephen
Ste
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stephen1212b · Post by **stephen1212b** » Mon Dec 10, 2007 6:34 pm

75 ohm termination is needed to prevent the digital signal from reflecting back on itself. It should be applied at the far end of the cable away from the clock source.

I seem to remember that the drivers for the 01V do not allow it to sync to the external digital input when connected to a Mac computer, otherwise that would be a fine plan. I have an 01X and it works fine as slave syncing over firewire to a Traveler as master in an aggregate device. The Traveler can still choose from any of its sync options including time code.

boomtime · Post by **boomtime** » Mon Dec 10, 2007 10:22 pm

stephen1212b wrote:To my knowledge the digital timepiece has never been noted for its great clock. It is very capable but not really what you need. The Big Ben would be a better choice or any other quality master word clock. I use an old Aardsync. Everything that can slaves to the master clock. I assume you will create an aggregate device to include the 01V. Make certain it is slaving to the 2408 mk 3 and the 2408 mk 3 will slave to external word-clock. The lexicon gear automatically slaves to its digital input and the output will therefor be in sync. You are limited to 44.1 K or 48 K sample rates on some of the gear and all of the gear needs to be set to the same sample rate and match the master word-clock sample rate. Try not to loop the clock signal from device to device, but run a separate line to each. You might also have to investigate 75 ohm termination that should be on for every device. If memory serves the 828 mk2 may need an external T adapter with an external 75 ohm termination plug.

Motu devices dont need to be terminated.

Also on the big ben you can run 4 word outputs BnC at say 44.1 - 192 and outputs 5&6 can be different values. the other digital outs outputs s/pdif etc can also have independant values.

Big ben is the way to go at $1100 !