User Manual

HARDWARE INSTALLATION
52
SYNCING S/PDIF DEVICES
The 1248 provides RCA (coax) S/PDIF digital
input and output. Your 1248 and the other S/PDIF
device will sync to each other by way of the S/PDIF
connection itself. One device is the master, and the
other device is the slave.
Syncing the 1248 to its S/PDIF input
When you transfer audio from the S/PDIF device
into the 1248, choose S/PDIF as the clock source
(item #13 on page 18) to resolve the 1248 to its
S/PDIF input.
S/PDIF input with sample rate conversion
The 1248 S/PDIF input provides sample rate
conversion, which allows you to record any S/PDIF
signal up to 96 kHz, even when the 1248 is resolved
to other clock sources besides S/PDIF. See “S/PDIF
with sample rate conversion” on page 46 for more
information.
Syncing another S/PDIF device to the 1248
When transferring audio from the 1248 to another
S/PDIF device, set the 1248’s clock mode (item #13
on page 18) to any source other than S/PDIF.
Doing so makes the 1248 the clock master. When
the other device records (or receives) S/PDIF audio
(from the 1248), it will simply synchronize to the
clock provided by the 1248 S/PDIF signal.
SYNCING OPTICAL DEVICES
There are several ways to sync an optical device
with your MOTU interface:
A. Resolve the other device to your MOTU
interface
B. Resolve your MOTU interface to the other
device
C. Resolve both devices to a word clock source
For A, choose Internal (or anything other than
Optical) as the clock mode in the Device tab (item
#13 on page 18). Then configure the other device
to resolve to its optical input.
For B, choose Optical as the clock mode (item #13
on page 18), and configure the other device to
resolve to its own internal clock.
For C, choose Word C lock as the clock mode for the
24Ai or 24Ao (item #13 on page 18), and resolve
the other device to its word clock input.
SYNCING WORD CLOCK DEVICES
The word clock connectors on your MOTU device
allow you to synchronize it with a wide variety of
other word clock-equipped devices.
For standard word clock sync, you need to choose
an audio clock master (as explained in “Be sure to
choose a digital audio clock master” on page 51).
In the simplest case, you have two devices and one
is the word clock master and the other is the slave
as shown below in Figure 4-11 and Figure 4-12.
Figure 4-11: Slaving another digital audio device to your MOTU
device (a 1248 in this example) via word clock. For the 1248 clock
source, choose any source besides word clock, as it is not advisable to
chain word clock.
Figure 4-12: Slaving your MOTU device (a 1248 in this example) to
word clock. For the 1248 clock source, choose ‘Word Clock In’.
Master
Slave
Word clock OUT
Word clock IN
Other device
1248
Audio
clock
Master
Slave
Word clock master device
Word clock OUT
Word clock IN
1248