User Manual-Windows

INSTALLING THE PCI-424 HARDWARE
48
SYNCING ADAT ‘LIGHTPIPE’ DEVICES
The word lightpipe is our short-hand way of
referring to any device that connects to a 2408mk3
interface via an ADAT optical cable. But we make a
further distinction: a lightpipe device is also one
that doesn’t care about sample location. An
example is a digital mixer. Since the digital mixer is
not a recording device, it has no sense of sample
location like an ADAT. An ADAT can cue to a
specific sample number (e.g. sample number
43,478, 103) — as can any device that supports
ADAT sync, but a digital mixer simply mixes and
processes audio digitally, with no sense of location
in time. There are many other devices that fall into
this category, including digital effects processors,
synthesizers, A/D converters, and many more.
For Alesis recorders or other devices that support
ADAT sync, sync them with a 2408mk3 as
described in the previous sections of this chapter.
For lightpipe devices, such as digital mixers, all you
have to do is make sure that their digital audio
clock is phase-locked (in sync with) the 2408mk3.
There are three ways to do this:
■ Slave the lightpipe device to the 2408mk3
■ Slave the 2408mk3 to the lightpipe device
■ Slave both the lightpipe device and the 2408mk3
to a third master clock (such as a Digital Timepiece
or MIDI Timepiece AV synchronizer)
ADAT
Sync out port
PCI-424 card
ADAT Sync In
ADAT Optical IN
ADAT Optical OUT
Digital mixer
or other lightpipe
device
2408mk3
With this setup, in the MOTU PCI
Audio Console window, choose
Internal, or any clock source
setting except one of the three
Optical In settings. The lightpipe
device slaves to the 2408mk3
(via its optical cable connection).
Digital mixer
or other lightpipe
device
ADAT Optical IN
ADAT Optical OUT
2408mk3
With this setup, in the MOTU PCI Audio
Console window, choose Optical In and
the Bank (A, B or C) to which the light-
pipe device is connected. The 2408mk3
slaves to the lightpipe device via their
optical cable connection.
Figure 4-28: Three setups for synchronizing a lightpipe device with a 2408mk3. You can slave the lightpipe device to the 2408mk3 or vice
versa with their optical connections. For more elaborate setups, you can slave both to a digital audio synchronizer like the Digital Timepiece.
Don’t use any of these setups for an ADAT or other optical device that records. Instead, see “Sample-accurate ADAT sync” on page 40.
Word Clock Out
Digital Timepiece
set to Internal
Word Clock IN
Computer with PCI-424 system
bi-directional
lightpipe
MOTU PCI Audio Console
Clock Source setting
Digital mixer
or other lightpipe
device