Tascam 788 - Manual (Page 94)

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TASCAM 788 Digital PortaStudio
11 – Synchronization
You can expand the options available to you when
using the 788 by connecting it and synchronizing it
to other musical equipment.
Typically, this extra equipment will be MIDI-based
(sequencers, drum machines, synthesizers, etc.).
Of course, although it is possible to record MIDI
instruments on the 788 tracks during the initial stages
of the recording project, it may make more sense to
use the eight audio tracks of the 788 for material that
cannot be automated via MIDI (guitars and other
acoustic instruments and of course vocals).
When it comes to mixdown time, the 788 allows you
to extend the eight available audio tracks by playing
additional sources through the sub-mixer and adding
them to the mix (see “Sub-mixer” on page 48).
To make this work, though, the MIDI instruments
and the 788 must be synchronized to each other, so
that playback on one set of sound sources (the
recorded audio tracks) keeps time with the sequenced
MIDI tracks.
The 788 can synchronize with MIDI equipment in a
number of different ways, as explained in this sec-
tion, allowing a high degree of flexibility in the
setup.
As well as synchronizing to other devices, it is also
possible for the 788 to control other devices or to be
controlled by them (see “MMC and MIDI functions”
on page 101).
NOTE
All synchronization is carried out through the two MIDI
ports on the rear panel of the 788, no matter what kind of
synchronization is used, or the role of the 788 in the syn-
chronization chain.
The 788 cannot use audible SMPTE/EBU timecode from
the timestripe track of a tape. If the source to be synchro-
nized with the 788 only has audible timecode available, it
must be converted to and from MIDI timecode (MTC) as
appropriate.
Master or slave?
The terms master and slave are used to name the con-
troller and the controlled units in a chain of devices
such as the 788 and other audio devices.
However, it is possible for a unit to be a master unit
in one configuration at the same time as being a slave
in another.
For example, the 788 may be set up to be a timecode
master (other units receive their timecode from the
788 and act accordingly), and a control slave (it
receives stop/start commands, etc.) from other units.
A 788 can also be a timecode (MTC) slave, and in
this way, two 788s can be synchronized.
How to measure time?
There are two ways of counting time in music: one is
the number of minutes and seconds since the begin-
ning of the piece. This is the way in which tape
recorders, etc. count time.
The other method of counting time is the number of
bars (measures) since the beginning of the piece.
This is the way in which MIDI sequencers typically
count time.
There is no direct relationship between these two
ways of counting, as the relationship depends on the
tempo of the piece.
When synchronizing, therefore, one unit in the chain
must be capable of making a map which relates the
minutes and seconds of one system to the bars and
beats of the other. If the tempo stays fairly constant
throughout a piece, this is a matter of fairly simple
arithmetic, but if the tempo changes through a piece,
this is not so easy to do.