MOTU V4HD User Manual page 30

Camera
Video out AES/EBU out
Video in AES/EBU in
Figure 3-16: When capturing digital audio from the current video
source, the V4HD genlocks to the source input, which keeps the
digital audio clock properly resolved to the video source audio clock.
Resolving a third device to the V4HD
If you need to make digital audio transfers between
the V4HD and third device (that is not the current
video source), you must resolve the third device to
the V4HD, as demonstrated in Figure 3-17. In this
example, the third device, a field recorder, is being
resolved to the V4HD via word clock. Alternately, it
could be resolved via AES/EBU or ADAT optical
input.
Camera
Video out
Video in
Word clock AES/EBU in
out
Word clock
AES/EBU out
in
Figure 3-17: Capturing digital audio from a third device that is not
the current video source. In this case, the third device must resolve to
the V4HD via word clock in, AES/EBU input or ADAT optical input.
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Resolving a digital mixer to the V4HD
If the V4HD is currently operating as a video
interface (i.e. Audio only mode is not enabled), and
you would like to connect a digital mixer via ADAT
optical or AES/EBU (or both), resolve the digital
mixer to the V4HD, either via its optical or
AES/EBU connection, or via word clock, similar to
what is shown in Figure 3-17.
Resolving to the VIDEO REF IN
If the V4HD is currently resolved to its VIDEO
REF IN, you can either resolve the other digital
audio device to the V4HD (Figure 3-17), or you
can resolve the other device to the same genlock
source that is feeding the V4HD's VIDEO REF IN.
In this scenario, the genlock source serves as a
master clock to which both the V4HD and the
other device are resolved (Figure 3-15).
Digital audio transfers in Playback only mode
When the V4HD is in Playback only mode (see
"Playback / Playback only" on page 38), resolve
other digital audio devices to the V4HD, either via
their optical or AES/EBU connection, or via word
clock, similar to what is shown in Figure 3-17.
Audio synchronization in 'Audio only' mode
If the V4HD video features are disabled with
"Audio only" mode (page 39), then the V4HD
operates as an audio interface with a variety of
options for digital audio clocking (without
requiring sample rate conversion). You can resolve
other digital audio devices to the V4HD or vice
versa, using word clock or their digital audio
connections (ADAT optical or AES/EBU).
If you choose the V4HD as the clock master, set its
audio clock source ("Clock Source" on page 73) to
Internal and resolve the other device to its word
clock or digital audio connection to the V4HD.
Field audio recorder resolved
to its word clock input
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