Almost everyone who uses Pro Tools needs to synchronize audio with something. How about a digital multitrack machine, or a D2 digital video machine, or a 3/4” video deck, or a film chain?

Synchronization is no stranger to Digidesign. In the past they have offered the Video Slave Driver and the SMPTE Slave Driver. They have done a perfect job of digital audio lockup. They now have combined all the features of both boxes, and more, into one Universal Slave Driver.

Sync Or Swim

When synchronizing two digital audio devices together, all you have to do is get them to the same spot, and let go to sample clock. You then have sample accurate lock forever. When synchronizing different sample rates, locking to picture, or even (heaven forbid) locking digital audio to an analog source, the potential problems rise exponentially. You must be able to vari-speed the slave (in this case, Pro Tools) to make it run second for second in sync with the master. The problem with most systems is increased jitter and distortion in the digital audio signal when chasing SMPTE or locking to the crystal of a video machine.

The USD generates Digidesign Superclock, which is basically a sync pulse 256 times higher resolution than a regular word clock. This signal then drives the sample rate of the Pro Tools system. If the video machine runs a little slow, then the USD slows down to match so that Pro Tools stays in sync throughout the show.

Out Standing In Its Field

The USD functions as an LTC reader and generator, a VITC reader and generator (with window burn), a stand-alone time code and clock format converter, and a master clock for Pro Tools workstations. If you want Pro Tools to me the master, then the USD will generate SMPTE based on Pro Tools play position.

The USD is one of those add-ons where you don’t have to think about it, you just get it. Later, you won’t know how you ever got along without it. By the way, do I get royalties if a piece of equipment is named after my wife?