TIMECODE RECORDING AND PLAYBACK
IN CUBASE 3.5 VST (WIN95)

Fig. 1 - 16-channel audio recording, recorded from ADAT locked to computer.

This App Note describes timecode recording / playback using Cubase VST and ADATs, using the standard MM ASIO driver and STUDI/O.  Timecode recording is when you have the computer following the ADAT tape so that it records and plays back in perfect synchronization (lock step) with the tape. 
 
 

Hardware	Software
Pentium-II 266MHz ASUS KN97-X motherboard  128MB RAM  DPT SCSI RAID controller  6x4GB Micropolis drives in RAID0  STUDI/O  2xADAT XT  MOTU Pocket Express  Steinberg ACI	Cubase Score VST 3.502  Sonorus 1.021 drivers  Virtual Memory OFF (that's right!)  Graphics Acceleration OFF

With this setup we were able to record 16 channels from the two ADAT XT's into the computer locked to timecode.  Then, we listened back to the recorded tracks, and the ADATs at the same time to make sure they were sync'd, and they were, over the whole 6 minute song! 

Here are the pertinent setup screens in Cubase: 

Fig. 2. Steinberg's ASIO MM setup.  

Setting smaller buffer sizes might work, but the more channels you're running, the bigger they need to be.  If they're too small, you might get a 'lost communication with soundcard' error in cubase, and/or real-time error in the driver. 

Fig. 3. Audio... System window. 

Note the sample rate should be set to the whatever the ADATs are running at.  Also note the disk block buffer size is cranked -- again you might get away with less, but that's what we used. 

. 
Fig. 4. Synchronization... window 

Setting MMC here allows transport control, etc. via Cubase.  Very nice!  Note that the Pocket Express has a different input for sync.  Also, make sure the frame rate here matches the ACI's frame rate. 
 

Note also, that we started recording at bar 4.  Currently, there is a problem with Cubase VST where you have to record at bar 2 or greater -- recordings from bar 1 would be out of sync.   

Here are Charlie Steinberg's comments (verbatim) on these settings:

a) buffer sizes are *very* large...5 * 8192 is almost one second of delay for all start audio, change volume and other params, automation...

b) disk block buffer size to 256k looks stupid to me; sizes like 128 or 256k are actually only useful for very slow seek media like floppy or cd-rom. especially if you have virtual memory off (really??), this looks like a useless waste of memory. I'd rather recommend 96k.

Keep in mind, that these are the settings that we used to get this setup working. But, as you see from Charlie's comments, additional tweaking of the buffer sizes might be required and/or desirable.

For more info and ideas about Cubase VST check out these Cubase user sites:

Questions? Comments? Email us at techsup@sonorus.com.

[end] 
 

Macintosh is a trademark of Apple Computers, Inc.
Windows 95, Windows MM System are trademarks of Microsoft Inc.
Studi/o is a trademark of Sonorus, Inc. Copyright © 1997 Sonorus, Inc. 
All rights reserved