User`s guide

INSTALLING THE 896HD HARDWARE
26
SYNCING AES/EBU DEVICES
If you would like to transfer stereo audio digitally
between the 896HD and another device that has
AES/EBU I/O, connect it to the 896HD’s AES/EBU
jacks with balanced, AES/EBU grade audio cables.
AES/EBU clock and sample rate conversion
The 896HD AES/EBU section is equipped with a
real-time sample rate converter that can be used for
either input or output. This feature provides a great
deal of flexibility in making digital transfers. For
example, you can:
■ Tr a n s fer dig i t al audio into the 896HD at a
sample rate that is completely different than the
896HD system clock rate.
■ Tr a n s fer dig i t al audio into the 896HD without
the need for any external synchronization
arrangements.
■ Tr ansfer digital audio out of the 896HD at
double or half the 896HD 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 3-15. 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
896HD
896HD
Clock Source setting =
Internal (when transferring from the
896HD to the AES/EBU device)
Figure 3-14: Two setups for synchronizing an AES/EBU device with the 896HD. In the top diagram, sync is achieved via the AES/EBU connection
itself. In this case, you have to choose AES/EBU as the 896HD’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 896HD or vice versa (not shown). The Word Clock connection maintains sync, regardless of the direction of the transfer.
896HD
Clock Source setting =
AES/EBU (when transferring from
the AES/EBU device to the 896HD)
Word Clock Out
MIDI Timepiece AV
set to Internal
ADAT Sync out
ADAT sync in
Word Clock IN
Computer with 896HD
AES/EBU
DAT deck
or other AES/EBU device
Mac
896HD
Clock Source setting =
ADAT 9-pin