1)  My Mac's external SCSI port produces +7 volts on the SCSI bus. The Synclavier likes +5.  Measure the DC voltage of pin 38.
2)  Make an adapter that lifts pin 38 of a 50 pin cable to remove TERMPWR from the Mac's external SCSI bus.
3)  If using both towers, leave the Synclavier's D24 TERMINATION RESISTORS and +5 TERMPWR on, connect to DtoD (making sure the D24 is  UNTERMINATED and TERMPWR is removed) with a SCSI 'T' connector on the SCSI 'IN' connector, then connect to the Mac's external SCSI connector with the special TERMPWR-REMOVAL adapter.
4)  If using a DtoD standalone, make sure that ABLE 0's SCSI is TERMINATED with TERMPWR ENABLED.  Use a modified SCSI 'T' connector to allow the Mac to plug into the DtoD (two males with one female 50 pin 'D' sub connector with wire 38 removed for the Mac).
5)  If converting sounds from optical to mac, connect in this order:  Mac, TERMPWR-REMOVAL adapter, Optical, then TERMINATED System Winchester.
6)  Make sure ALL devices EVERYWHERE have "power from SCSI bus" enabled regardless if they are terminated or not.  Only the Synclavier D24 should make +5.
7)  Remove ALL extensions except OPEN TRANSPORT, QUICKTIME and their respective helper files.
8)  Give S/Link all available memory.
9)  Use BIG-ASS SCSI cables - no cheap ones allowed - heavy, triple shield.
10)  Make sure there are NO semi corrupted files on the optical and system winchester and no other files but sound files.
11)  Try not to reset the computers during a read/write operation (disk light active), even if the mac looks "hung".  Give it a second. If necessary, then reset the "Drive Reset" on the DtoD or the mac's software reset - control, open apple, del.
12  When using the Synclavier with optical, connect Synclavier to Optical to Winchester (terminated).

Transfers will be faster because there is no bizarre voltage potentials on the SCSI bus (you can burn out devices otherwise).  Hang-ups will occur less.  The possibility of quitting S/Link without the Mac bombing will increase.

--
Brandon Amison
Yaking Cat Music Studios
Synclavier Assistance
Music for Television and Film
http://home.earthlink.net/~yaking/
THE source of Synclavier information

The 3200/6400/9600 require the use of a terminator  into the Expansion Port as the internal drives are NOT terminated.

When using a DtoD slaved to the Synclavier 3200/6400/9600 the configuration is as follows:
Synclavier Expansion Port Out to DtoD SCSI In.  If using an Optical Drive, the drive is placed in-between the two towers and NOT terminated.  Termination is achieved through the two D24/50 boards.

http://www.idbdnet.com/infotech/scsisolved.html

Apparently most Macs supply TERMPWR to the SCSI bus.  One has to make
sure with older drives to 1) remove termination unless at the end of the
chain and 2) jumper "receive power from SCSI bus only".  Termination and
power are two different things.  On newer devices, they sometimes supply
voltage even though you don't want it.   You have to physically cut the
cable line leading to TERMPWR.  This causes differentials in the voltage
which leads to slower transmission and/or occasional to complete
errors...

Internal lengths are:
Optical = 6"
Winchester = 18"
Synclavier/DtoD computer panel = 14"

These lengths have to be considered when calculating Total Cable Length (18 feet max.)

For information on proper termination go to
http://lowendmac.com/tech/termination2.shtml
or
http://lowendmac.com/tech/termination.shtml

And for every topic you can imagine
http://macsupport.about.com/compute/macsupport/msub10.htm?iam=dp&rf=dp

Even though I've never seen the source code for this program, I think it's
fair to say that if it crashes this frequently and consistently, it must
just be poorly written.

Even aside from the feeling one gets when using S/tink that you should cross
your fingers and pray while a transfer is in progress, it has so many
annoying quirks and things that just plain don't work right.  I can't wait
for Cameron's AIFF translators.

Todd Humongous

To download S/Link, go here

Todd Yvega wrote: 

   Not true.  Zappa's G3 has the CD drive on the ATA bus, and S/Tink works fine here (so it HAS to
   work there.)

Bizarre.  That is supposed to be the golden rule.  Sean Callery couldn't get his to work and he has a
G3 with a built-in CD-ROM also.  Your experience is contrary to what I have read in several articles
(as if we can really believe what we read in music/computer magazines...)

Oh well.  Color me dumb! - Brandon (maybe it is IDE drives...) Actually, I just read about it at http://www.xlr8yourmac.com/audio/issue12.html

However, S/Link works PERFECTLY with the Synclavier - Don't I wish ;-) 

I bought S/Link directly from Airworks by telephone.  The company never 
got around to charging my credit card.  I STILL FEEL CHEATED!!!
-Todd Yvega

I had to change the names of several dozen files to perform my last job duty.  They should pay us to use S/Link.

IMPORTANT INFORMATION:  once this modification is made, you *MAY* have to use an active terminator if you wish your system to run as a stand-alone machine or without S/Link.  Here is a better alternative:

On the back of my PostPro are four "Time Expansion" connectors which lead straight to the hard drives.  By connecting your Mac to these ports, the tracks come off at a 2 to 3 times faster rate.  Before I did this, I was receiving "Read-Errors".  It looks as if the data was having to make too many "connections" (SCSI cards, several feet of cable, etc.) before it got to the Mac.  I was told by Andy Pettit of Airworks to also try using an APS SCSI Sentry or active termination and increasing the memory to the application.  This did not help in my case (I have only a generic active terminator, however).

I am now tape free.  I mix my DtoD and Synclavier tracks to 2 tracks on the DtoD.  I then S/Link them to the Mac for cue editing in ProTools to be placed onto Zip disks or a CD-RW.  Let me tell you folks, the sound is incredible.  *NO MORE TAPE!*