The ADATs like to be the master.  It did seem to make sense.  The ADATs could generate their own SMPTE, plus, they could be the wordclock master to the O2Rs.  It made sense in my mind, but to explore this as the actual solution meant spending a couple of thousand on a Lynx setup.  I decided that I believed enough in this theory that I would run it by the studio owners as if I might emerge the hero.

What is entailed is having the Micro Lynx, a synchronization device, take over the machine control of the Otari 2” analog deck.  A Lynx will read two separate SMPTE timecodes, and using one deck as the master, have the 2nd deck chase the master.  Some analog decks are harder than others to sync, but the Otari is designed with a sync input for just this purpose.

This type of thing is done all of the time when locking two analog decks to each other.  When you’ve heard of 48 track recording, at least up until recently, this referred to the synchronizing of two 24 track decks using such a device.  One deck would be the master, while the “slave” deck’s motor would be controlled by the Lynx synchronizer.  The Lynx would analyze the SMPTE position of each deck, and if the slave deck didn’t match the position of the master, the slave deck would reposition itself accordingly.

The major problem in achieving this in the opposite direction (with the ADATs slaved to the 2” deck), as described in Part 1, is that the SMPTE on the analog deck will vary slightly.  How slightly?  Slightly enough that the ADATs couldn’t maintain their digital wordclock timing.  I don’t have any numbers for what the actual tolerance is, but I believe the official figure to be +/- zilch.

Popping and clicking are the Beavis and Butthead of digital audio artifacts, commonly recognized as a result of wordclock timing problems, and equally as unfunny (Beavis and Butthead fans, please forgive me).  Understand that the O2Rs are digital boards, and we were taking lightpipe out of the ADATs to lightpipe in of the O2R’s lightpipe expansion cards.  But what if we, for arguments sake, had come analog out of the ADATs to the analog inputs of the O2Rs?  I touched on this in part one, now here’s the foray into verbose mode.

Can you imagine a world without hypothetical situations?  What if we came analog out of the ADATs?  The question here is, how analog is a digital to analog conversion?  Answer- it will forever have been chopped up into 48,000 pieces (just go with this use of the English language).  Just like a motion picture, where we’re viewing 24 discrete pictures every second, we perceive it as continuous.  The reality is, there are 24 discrete pictures.

It’s when you take those 48,000 pieces of audio and chop it up 48,000 times again, that a different phenomenon occurs.  It’s not exactly an artifact, but the result is a thin, hollow quality to the audio.  Results will vary according to the quality of all D/A and A/D involved, but there is a definite drawback to sampling audio that has previously been digitized- when wordclocks are not synchronized!!

So we’re basically still in the same boat.  Coming analog out of the ADATs to the analog ins of the O2Rs would have solved our fundamental wordclock popping and clicking problem, but we would still be left with a wordclock issue.  Back to the Lynx.

I had my chat with the studio owners.  Everyone had been driven to varying degrees of insanity from all of this.  We seemed to be so close in the current sync scenario.  Some days were good days, with a very occasional pop and click.  Some days there were more, with the eventual complete drop of audio from the O2Rs.  We considered sunspots, or static electricity, and even tried a negative ion generator.  It was a brief chat, and they agreed to the Lynx.

Its way too late to make a long story short, but making the ADATs the master, having them send SMPTE to the Lynx, having that SMPTE control and drive the Otari analog deck (in conjunction with reading SMPTE from the Otari), having the ADATs send wordclock to the O2Rs slaving to incoming wordclock sync..  Well, let me say that the world had color again, everyone was suddenly nice, and smiling.  Oh yes, and the audio no longer popped and clicked.  The O2Rs passed audio in the continuous fashion that we all had come to know and love.  It was a beautiful thing.

JD Mars is the Producer of Digital Pro Sound.

Take me to Part One