User`s guide

INSTALLING THE MOTU 896 HARDWARE
28
SYNCING AES/EBU DEVICES
If you would like to transfer stereo audio digitally
between the 896 and another device that has AES/
EBU I/O, connect it to the 896’s AES/EBU jacks
with balanced, AES/EBU grade audio cables.
AES/EBU clock and sample rate conversion
The 896 AES/EBU section is equipped with a real-
time sample rate converter that can be used for
either input or output. This feature provide a great
deal of flexibility in making digital transfers. For
example, you can:
■ Transfer digital audio into the 896 at a sample
rate that is completely different than the 896 system
clock rate.
■ Transfer digital audio into the 896 without the
need for any external synchronization
arrangements.
■ Transfer digital audio out of the 896 at double or
half the 896 system clock rate.
Rate conversion does not add any appreciable noise
to the audio signal (under -120 dB).
Digital audio phase lock
Without sample rate conversion, when you transfer
digital audio between two devices, their audio
clocks must be in phase with one another — or
phase-locked — as demonstrated below in
Figure 4-14. Otherwise, you’ll hear clicks, pops,
and distortion in the audio, or perhaps no audio at
all.
AES/EBU
AES/EBU
DAT deck
or other AES/EBU
device
MOTU 896
MOTU 896
Clock Source setting =
Internal (when transferring from the
MOTU 896 to the AES/EBU device)
Figure 4-13: Two setups for synchronizing an AES/EBU device with the MOTU 896. In the top diagram, sync is achieved via the AES/EBU connec-
tion itself. In this case, you have to choose AES/EBU as the MOTU 896’s clock source when recording from the AES/EBU device. If you don’t want
to have to worry about switching the Clock Source setting depending on the direction of the AES/EBU transfer, you can slave the AES/EBU device
to word clock from the MOTU 896 or vice versa (not shown). The Word Clock connection maintains sync, regardless of the direction of the trans-
fer.
MOTU 896
Clock Source setting =
AES/EBU (when transferring from
the AES/EBU device to the MOTU 896)
Word Clock Out
MIDI Timepiece AV
set to Internal
ADAT Sync out
ADAT sync in
Word Clock IN
Computer with MOTU 896
AES/EBU
DAT deck
or other AES/EBU device
PC
MOTU 896
Clock Source setting =
ADAT 9-pin
!896 Manual/Win Page 28 Tuesday, November 27, 2001 5:02 PM