Syncing Optical Devices - MOTU 828mkII User Manual

SYNCING OPTICAL DEVICES

The word optical is our short-hand way of referring
to any device that connects to the 828mkII via an
optical cable. But we make a further distinction: an
optical device is also one that doesn't care about
sample location. An example is a digital mixer.
Since a digital mixer is not a recording device, it has
no sense of sample location like an ADAT does. An
ADAT can cue to a specific sample number (e.g.
sample number 43,478, 103) — as can any device
that supports ADAT sync, but most digital mixers
simply mix and process audio digitally, with no
sense of a specific sample location. There are many
other devices that fall into this category, including
digital effects processors, synthesizers, A/D
converters, and many more.
828mkII
ADAT Optical OUT
ADAT Optical IN
Digital mixer
or other optical
device
828mkII
Clock Source setting =
Internal, or any clock source
setting except Optical. The optical
device slaves to the 828mkII (via
its optical cable connection).
Figure 3-16: Three setups for synchronizing an optical device with the 828mkII. You can slave the optical device to the 828mkII or vice versa
with their optical connections. For more elaborate setups, you can slave both to a digital audio synchronizer like the Digital Timepiece. Don't
use any of these setups for an ADAT or other optical device that records. Instead, see "Sample-accurate ADAT sync" on page 25.
I N S T A L L I N G T H E 8 2 8 M K I I H A R D W A R E
For ADATs or other devices that support ADAT
sync, synchronize them with the 828mkII as
described in the previous sections of this chapter.
For optical devices, such as digital mixers, all you
have to do is make sure that their digital audio
clock is phase-locked (in sync with) the 828mkII.
There are three ways to do this:
Slave the optical device to the 828mkII
■
Slave the 828mkII to the optical device
■
Slave both the optical device and the 828mkII to
■
a third master clock (such as a Digital Timepiece or
MIDI Timepiece AV synchronizer)
Digital mixer
or other optical
device
828mkII
MIDI Timepiece AV
set to Internal
Word Clock Out
Digital mixer
Word Clock IN
or other optical
device
bi-directional
With this setup, in the MOTU
FireWire Audio Console, choose
the Optical clock source setting.
The 828mkII slaves to the optical
device via their optical cable
connection.
ADAT Optical OUT
ADAT Optical IN
ADAT Sync out
Mac
ADAT sync in
Computer with 828mkII
optical
828mkII
Clock Source setting =
optical
828mkII
Clock Source setting =
ADAT 9-pin
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