MOTU V4HD User Manual page 25

AES/EBU digital audio I/O
The V4HD provides eight channels of 24-bit
AES/EBU digital audio input and output at
standard sample rates from 44.1 kHz up to 96 kHz.
4-channel vs. 8-channel operation
As shown in Figure 3-5, the AES/EBU section
supplies four XLR connectors directly on the rear
panel. These input and output jacks provide four
channels each of AES/EBU digital input and output
via direct connection to the V4HD rear panel using
standard AES/EBU-grade cables.
Similar to the analog section, as explained in
"8-channel operation" on page 24, the V4HD
provides eight channels of AES/EBU input or
output using a DB25-to-XLR breakout cable (sold
separately). However, the requirements for this
cable are different than those for the analog
section. The AES/EBU breakout cable supplies 8
channels of AES/EBU input on four female XLR
connectors and 8 channels of AES/EBU output on
four male XLR connectors, as shown in Figure 3-7.
Figure 3-7: An example of a DB25-to-XLR breakout cable (sold
separately) for 8-channel AES/EBU input and output. This cable has
four female XLR connectors and four male XLR connectors. See
Appendix D, "DB25 to XLR Pin Outs" page (111) for pin out details.
Similar to the analog section, XLR and breakout
cable operation in the AES/EBU section are
mutually exclusive. You cannot use both the XLR
jacks and the breakout cable at the same time.
☛
For best performance (and to avoid issues
with termination and impedance levels), do not
connect cables to the rear panel XLR jacks and the
DB25 cable in the same section at the same time.
I N S T A L L I N G T H E V 4 H D H A R D W A R E
Synchronization and sample rate conversion
When making AES/EBU digital audio transfers to
and from the V4HD, the two devices must be
synchronized with one another, or you must
employ the V4HD's sample rate conversion. See
"Syncing digital audio devices" on page 29.
ADAT optical digital I/O
The V4HD provides 8-channel ADAT optical
digital input and output at 44.1, 48, 88.2 and 96
kHz. The V4HD rear panel provides two sets of
ADAT optical ("lightpipe") connectors to support
8-channel operation even at the 2x sample rates
(88.2 or 96 kHz).
Reminder: optical goes OUT to IN and IN to OUT.
Input and output are independent. For example,
you could connect ADAT optical input from your
digital mixer and connect the output to another
optical-equipped device.
Optical operation at 44.1 or 48 kHz
When connected to an ADAT "lightpipe"
compatible device, the two optical connectors
marked IN and OUT provide eight channels of
digital input and output at 44.1 and 48 kHz.
In addition, when operating the V4HD at a 1x
sample rate (either 44.1 or 48 kHz), optical output
is duplicated on the second optical output marked
5-8@96K. This lets you send the V4HD's 8-channel
ADAT optical output to two separate destinations
in your studio, if needed.
Optical operation at 88.2 or 96 kHz
When operating the V4HD at the 2x sample rates
(88.2 or 96 kHz), the two optical connectors
marked IN and OUT provide channels 1-4 (in and
out) and the second set of optical connectors
marked 5-8@96K provide channels 5-8 (in and
out) when connected to another optical device that
supports 88.2/96 kHz optical sample rates.
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