Synchronization - MOTU 828mkII User Manual

Figure 9-3: Fine-tuning the timing of audio playback and recording.

SYNCHRONIZATION

AudioDesk can run under its own transport
control or slave to an external sync source, such as
SMPTE time code or ADAT sync (sample address).
Running AudioDesk under its own transport
control
If you do not need to synchronize AudioDesk with
time code or another recording device, such as a
tape deck, just leave the Slave to External Sync
command in the Studio menu (Basics menu under
OS 9) unchecked.
However, even though AudioDesk is not slaving to
external sync, you still need to be concerned with
the synchronization of the 828mkII's digital audio
clock with other devices connected to it digitally (if
any). For example, if you have a digital mixer
connected to the 828mkII via an ADAT optical
lightpipe cable, you need to make sure that their
audio clocks are phase-locked. For details, see
"Syncing optical devices" on page 29 and "Making
sync connections" on page 22. If you don't have any
digital audio devices connected to the 828mkII,
digital audio phase-lock does not apply to you.
Resolving AudioDesk and the 828mkII to
SMPTE time code
If you need to slave AudioDesk and the 828mkII to
SMPTE time code, you can do so with or without a
dedicated synchronizer.
A U D I O D E S K
Resolving directly to time code (with no
synchronizer)
To resolve your AudioDesk/828mkII system
directly to SMPTE time code with no additional
synchronization devices, use the setup shown in
"Syncing to SMPTE time code" on page 54.
Choose Receive Sync from the Setup menu (Basics
menu under Mac OS 9) and choose the Sample
accurate option. Then make sure that the Slave to
External Sync command in the Studio menu
(Basics menu under Mac OS 9) is checked. Make
sure the Clock Source setting in the MOTU
FireWire Audio Console window is set to SMPTE.
Also, make sure that you've connected an LTC
input signal the 828mkII SMPTE input.
Resolving to video and/or time code with a
dedicated synchronizer
To resolve your AudioDesk/828mkII system to
video and/or SMPTE time code using an
additional synchronization device, use the setup
shown in "Syncing to video and/or SMPTE time
code using a synchronizer" on page 60.
Choose Receive Sync from the Setup menu (Basics
menu under Mac OS 9) and choose the MTC
(MIDI Time Code) option. Then make sure that
the Slave to External Sync command in the Studio
menu (Basics menu under Mac OS 9) is checked.
To ensure that your audio tracks don't drift out of
sync with your MIDI tracks — or time code, use a
hardware synchronizer like the MIDI Timepiece
AV or Digital Timepiece to resolve the 828mkII
hardware as well, as shown in Figure 5-30 on
page 62. A digital audio synchronizer is required
for drift-free SMPTE/MIDI time code sync. Make
sure the Clock Source setting in the MOTU
FireWire Audio Console window has the
appropriate setting for locking the 828mkII to the
synchronizer. For example, in Figure 5-30 on
page 62, word clock is being used to resolve the
828mkII, so the Clock Source setting is Word Clock
In.
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