Clock Source - MOTU 828 Mk III Hybrid User Manual

Clock Source

The Clock Source determines the digital audio
clock that the 828mk3 will use as its time base. For
a complete explanation of synchronization issues,
see "Making sync connections" on page 28. The
following sections briefly discuss each clock source
setting.
Internal
Use the Internal setting when you want the 828mk3
to operate under its own digital audio clock. For
example, you may be in a situation where all you
are doing is playing tracks off hard disk in your
digital audio software on the computer. In a
situation like this, you most often don't need to
reference an external clock of any kind.
Another example is transferring a mix to DAT. You
can operate the 828mk3 system on its internal
clock, and then slave the DAT deck to the 828mk3
via the S/PDIF connection (usually DAT decks
slave to their S/DIF input when you choose the
S/PDIF input as their record source) or via the
828mk3's word clock output (if your DAT deck has
a word clock input).
If you would like help determining if this is the
proper clock setting for your situation, see
"Making sync connections" on page 28.
Word Clock In
The Word Clock In setting refers to the Word Clock
In BNC connector on the 828mk3 rear panel.
Choosing this setting allows the 828mk3 to slave to
an external word clock source, such as the word
clock output from a digital mixer.
S/PDIF
The S/PDIF clock source setting refers to the
S/PDIF RCA input jack on the 828mk3. This
setting allows the 828mk3 to slave to another
S/PDIF device.
M O T U A U D I O C O N S O L E
Use this setting whenever you are recording input
from a DAT deck or other S/PDIF device into the
828mk3. It is not necessary in the opposite
direction (when you are transferring from the
828mk3 to the DAT machine).
For further details about this setting, see "Syncing
S/PDIF devices" on page 30.
ADAT Optical A / B
The ADAT optical clock source settings (ADAT
Optical A and ADAT Optical B) refer to the clock
provided by the 828mk3's two optical inputs, when
either one is connected to another optical device.
These two settings only appear in the Clock Source
menu when their corresponding optical bank input
is enabled and set to the ADAT Optical format, as
explained in "Optical input/output" on page 39.
This setting can be used to resolve the 828mk3
directly to the optical input connection. Most of
the time, you can set up a better operating scenario
that uses one of the other synchronization options.
However, there may be occasions when you have an
optical device that has no way of synchronizing
digitally to the 828mk3 or an external
synchronizer. In this case, the ADAT Optical clock
source setting lets you slave the 828mk3 to the
device itself via its digital input to the 828mk3.
This setting is also useful if you just need to make a
simple, click-free digital transfer between the
828mk3 and another device — where a time code
reference and shared transport control are not
needed — without having to set up an elaborate
synchronization scenario.
For further details, see "Choosing a clock source
for optical connections" on page 24.
TOSLink A / B
The TOSLink clock source settings (TOSLink A and
TOSLink B) refer to the clock provided by the
828mk3's two optical inputs, when either one is
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