HD, Sync I/O, loop sync and clocking

[Will Russell]

Hi,

I need a straight answer. I was originally under the impression that the loop sync in the new HD I/Os made the use of an external clock source uneccessary. I've since been told that clocking with the Sync I/O will sound better. Most recently I've read that the clock in the 192 I/O, which I have, is exactly the same as the clock in the Sync I/O. Anyone got the straight scoop on this?

[ekuehnl]

The Sync I/O does not substantially impact the sound of the system. If you need versatile sync functionality, you should definitely get one. Otherwise, stick with the internal clock of the 192 I/O.

[O.G. Killa]

Hi,

I need a straight answer. I was originally under the impression that the loop sync in the new HD I/Os made the use of an external clock source uneccessary. I've since been told that clocking with the Sync I/O will sound better. Most recently I've read that the clock in the 192 I/O, which I have, is exactly the same as the clock in the Sync I/O. Anyone got the straight scoop on this?

Loop sync does not make the use of an external clock un-necessary. Loop Sync syncronizes 192s, 96s, and legacy 888s together within the Protools TDM system. Any digital devices outside of this (DAT machines, A/D D/A Converters, digital mixers, etc) also have their own internal clocks. To get those external devices to function properly all devices (Protools and external) should have one master source for clock. Depending on your setup protools might be the master, or a digital mixing board might be the master...or a word clock generator like the Apogee Big Ben might be the master.

But regardless of whether or not you use an external clock or the internal protools clock, you still need loop sync for all digi devices.

[Sean Halley]

Just as a clarification, you should be using the Ext Clock Output on the 192 to feed an 888 connected via the Legacy port, not Loop Sync...the Ext Clock port needs to be set to transmit Superclock, not regular Word....

S..

[Will Russell]

Ok, so what I'm hearing is that in my system with 2 192 IOs loopsynced together, no need to lock to timecode etc and no other digital devices that need word clock it is not necessary to use the SYNC as a clock, correct?

Thanks for your input. Apparently even some Digi folks are confused by this.

[LFOT]

... I was originally under the impression that the loop sync in the new HD I/Os made the use of an external clock source uneccessary. I've since been told that clocking with the Sync I/O will sound better...

The scoop is that if you want your HD rig to sound better, try using an external clock like an Apogee Big Ben or something else with multiple WC outputs. Pull out your Loop Sync cables and hook up each 192 and your Sync I/O to the individual WC sends. You will lose the ability to alter your Sync I/O VSO, but with the Big Ben you can alter VSO from it's own hardware menu. Sounds like a hassle compared to the simplicity of the Loop Sync setup, but it sounds wider and more open (and all sorts of other BS audio-snob terms for "better").

No, I don't work for Apogee. Just a satisfied user.

[Erinugene]

Hello

I am very intrested in this topic.

I am considering adding an Apogee AD-16X with the direct connect card to my HD3 rig with 2 - 192 Digi I/Os.

I spoke with Apogee about this yesterday.
Seems like selecting the Apogee as clock source should result in a comparable improvement to using a Big Ben as master clock.

Quote From Apogees web site:

"Introducing the Apogee X-Series.
Changing the Face of Digital Audio... Again.

Featuring BIG BEN's C777 clocking technology and optional
X-Series Expansion Cards for direct connection to
Pro Tools | HD "

Am I correct in my thinking ?? Comments?..

Thanks, Aaron

[Erinugene]

Hello

Any comments on this ? Apogee AD-16X as Master clock thru Pro Tools loop sync Verses Big Ben as Master Clock.

Thanks, Aaron