MOTU PCI-424, User Manual

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I N S T A L L I N G T H E P C I - 4 2 4 H A R D W A R E
50
SYNCING SPDIF DEVICES
DAT decks and other SPDIF devices will sync to a
2408mk3 interface in one of two ways:
■
Via the SPDIF connection itself
■
Via word clock
SPDIF devices with no word clock
If your DAT deck or other SPDIF device has no
word clock sync connectors, just connect it to the
2408mk3 via the SPDIF connectors. When the
SPDIF device is programmed to receive digital
audio on its input (from the 2408mk3), it will
simply synchronize to the clock provided by the
audio input.
On the other hand, when you transfer audio from
the SPDIF device into the 2408mk3, you’ll have to
slave the 2408mk3 to the SPDIF input. If you have
other digital audio devices connected to the
2408mk3, and they are not slaved directly to the
2408mk3 itself, you may hear clicks and pops
resulting from their unsynchronized audio clock. If
so, just turn them off during the transfer.
SPDIF devices with word clock
If your SPDIF device has a Word Clock input,
connect the 2408mk3’s word clock Output to the
SPDIF device’s Word Clock input. You can then
freely transfer audio between the 2408mk3 and the
SPDIF device, regardless of how the rest of your
2408mk3 rig is synchronized.
SPDIF
SPDIF
DAT deck
or other SPDIF device
2408mk3
With this setup, in the MOTU PCI Audio
Console window, choose
Internal , or any
other clock source setting except SPDIF.
The DAT deck (or other SPDIF device)
slaves to the 2408mk3 via word clock for
SPDIF transfers in both directions.
Word Clock Out
Word Clock In
SPDIF
SPDIF
DAT deck
or other TDIF device
2408mk3
MOTU PCI Audio Console window
Clock Source setting
MOTU PCI Audio Console window
Clock Source setting
When transferring from
the 2408mk3 to the SPDIF device
When transferring from
the SPDIF device to the 2408mk3
Figure 4-30: Two setups for synchronizing an SPDIF device with a 2408mk3. In the top diagram, sync is achieved via the SPDIF connection itself.
In this case, you have to choose SPDIF as the PCI-424’s clock source when recording from the SPDIF device. If you don’t want to have to worry
about switching the Clock Source setting depending on the direction of the SPDIF transfer, you can slave the SPDIF device to word clock from the
2408mk3 or vice versa (not shown). The Word Clock connection maintains sync, regardless of the direction of the transfer.