User`s guide

INSTALLING THE TRAVELER HARDWARE
27
MAKING SYNC CONNECTIONS
If you connect devices digitally to the Traveler, or if
you need to synchronize the Traveler with an
outside time reference such as SMPTE time code,
you must pay careful attention to the synchroni-
zation connections and clock source issues
discussed in the next few sections.
Do you need to synchronize the Traveler?
If you will be using only the Traveler’s analog inputs
and outputs (and none of its digital I/O), and you
have no plans to synchronize your Traveler system
to SMPTE time code, you don’t need to make any
sync connections. You can skip this section and
proceed to “MOTU FireWire Audio Console” on
page 39 where you’ll open the MOTU FireWire
Audio Console and set the Clock Source setting to
Internal as shown below. For details, see “Clock
Source” on page 40.
Figure 4-9: You can run the Traveler under its own internal clock when
it has no digital audio connections and you are not synchronizing the
Traveler system to an external time reference such as SMPTE.
Situations that require synchronization
There are three general cases in which you will
need to resolve the Traveler with other devices:
■ Synchronizing the Traveler with other digital
audio devices so that their digital audio clocks are
phase-locked (as shown in Figure 4-10)
■ Slaving the Traveler system to SMPTE time code
from a video deck, analog multi-track, etc.
■ Both of the above
Synchronization is critical for clean digital I/O
Synchronization is critical in any audio system, but
it is especially important when you are transferring
audio between digital audio devices. Yo u r s u ccess
in using the Traveler’s digital I/O features depends
almost entirely on proper synchronization. The
following sections guide you through several
recommended scenarios.
Be sure to choose a digital audio clock master
When you transfer digital audio between two
devices, their audio clocks must be in phase with
one another — or phase-locked. Otherwise, you’ll
hear clicks, pops, and distortion in the audio — or
perhaps no audio at all.
Figure 4-10: When transferring audio, two devices must have phase-
locked audio clocks to prevent clicks, pops or other artifacts.
There are two ways to achieve phase lock: slave one
device to the other, or slave both devices to a third
master clock. If you have three or more digital
audio devices, you need to slave them all to a single
master audio clock.
Figure 4-11: To keep the Traveler phased-locked with other digital
audio devices connected to it, choose a clock master.
Also remember that audio phase lock can be
achieved independently of time code (location).
For example, one device can be the time code
master while another is the audio clock master. But
only one device can be the audio clock master. If
you set things up with this rule in mind, you’ll have
trouble-free audio transfers with the Traveler.
Not phase-locked Phase-locked
Device A
Device B
Master
Slave
Master
Slave Slave
!Traveler Manual/Win Page 27 Monday, November 29, 2004 3:50 PM