Chapter 6: Backup; Backup Basics; Backing Up Via Digital I/O - Alesis ADAT Reference Manual

CHAPTER 6: BACKUP

6.0

BACKUP BASICS

With analog recording, backing up from one multitrack to another loses one
generation, which adds hiss and distortion. With digital recording, backing up
produces an exact copy or "clone" of the original tape being backed up. This makes it
easy to create safety copies of important tapes, or make multiple copies for
distribution.
Because of ADAT's careful transport and format design, a good quality S-VHS tape
handled properly can be capable of over 1,000 play or record passes across the
head drum without any change to the audio. However, all tapes and environments
are not equal, and no tape of any format, analog or digital, video or reel-to-reel, lasts
forever. When tapes begin to wear out or have dropouts, the ADAT will give you
advance notice via the Advanced Information Indicator (see Section 9.4A). Since
one of the advantages of ADAT is its ability to make digital backups, and another is
the relatively low cost of S-VHS tape, you should make backup safety copies of all
tapes whenever you have invested a great deal of work into that tape. If you have
only one ADAT, your dealer or a local studio may offer an ADAT backup service.
6.1

BACKING UP VIA DIGITAL I/O

Alesis recognizes the importance of backup, so ADAT includes a fiber optic digital
connection that carries all eight ADAT tracks.
There are two ways to make digital copies of an entire ADAT tape:
In the normal method, you make an exact "clone" of the original with the copy
synchronized to the ADAT's internal time code numbering. Use this method if you
have a multi-ADAT setup, or if you're using a BRC, AI-2, or other ADAT time code-
based product. The original and the copy will be interchangable, with no change in
the time code offset.
It is also possible to make a digital copy using the optical I/O only, without sync
connections. The only thing that will be different between the copy and the original
will be the ADAT time code. Such copies won't play back the same time code at the
same point in the song as the original. Even so, such non-corresponding time code
copies can still be synchronized to the original with sample accuracy by using the
BRC and finding the proper offset.