Clock Source - MOTU 896mk3 User Manual

Operation at 4x sample rates (176.4 or 192kHz)
At the 4x sample rates (176.4 or 192kHz) the
896mk3 provides eight channels of analog input
and eight channels of analog output, simulta-
neously. However, operation of the 896mk3 is
restricted, due to the higher audio bandwidth
demands, as follows:
All digital I/O is disabled (there is no optical,
■
S/PDIF or AES/EBU input/output).
The stereo return bus, as described in "Return
■
Assign" on page 39, can only be assigned to one of
the four available analog output pairs or main outs.
The PHONES jack can only be assigned to one
■
of the four available analog output pairs.
The MAIN OUT jack can only be assigned to
■
one of four analog output pairs or the main outs.

Clock Source

The Clock Source determines the digital audio
clock that the 896mk3 will use as its time base. For
a complete explanation of synchronization issues,
see "Making sync connections" on page 21. The
following sections briefly discuss each clock source
setting.
Internal
Use the Internal setting when you want the 896mk3
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 896mk3 system on its internal
clock, and then slave the DAT deck to the 896mk3
via the AES/EBU connection (usually DAT decks
slave to their AES/EBU input when you choose the
AES/EBU input as their record source) or via the
896mk3's word clock output (if your DAT deck has
a word clock input).
M O T U A U D I O S E T U P
If you would like help determining if this is the
proper clock setting for your situation, see
"Making sync connections" on page 21.
Word Clock In
The Word Clock In setting refers to the Word Clock
In BNC connector on the 896mk3 rear panel.
Choosing this setting allows the 896mk3 to slave to
an external word clock source, such as the word
clock output from a digital mixer or another
MOTU FireWire interface.
S/PDIF
The S/PDIF clock source setting refers to the
S/PDIF RCA input jack on the 896mk3. This
setting allows the 896mk3 to slave to another
S/PDIF device.
Use this setting whenever you are recording input
from a DAT deck or other S/PDIF device into the
896mk3. It is not necessary in the opposite
direction (when you are transferring from the
896mk3 to the DAT machine).
For further details about this setting, see "Syncing
S/PDIF devices" on page 24.
AES/EBU
The AES/EBU clock source setting refers to the
AES/EBU input connector on the 896mk3. This
setting allows the MOTU 896mk3 to slave to
another AES/EBU device.
Use this setting whenever you are recording input
from a DAT deck or other AES/EBU device into the
896mk3. It is not necessary in the opposite
direction (when you are transferring from the
896mk3 to the DAT machine).
For further details about this setting, see "Syncing
AES/EBU devices" on page 25.
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