MOTU micro express-USB, Руководство пользователя

Страница: 124 / 156

S Y N C H R O N I Z A T I O N W I T H T H E A V
122
drop). This ensures that the audio you record will
be recorded at the exact sample rate you have
chosen in the MIDI Timepiece AV LCD.
SLAVING ADATS
The MIDI Timepiece AV is programmed out of the
box to automatically establish synchronization
with an ADAT or chain of ADATs connected to its
ADAT Sync Out port. The MIDI Timepiece AV will
automatically set the first ADAT it sees to
Device ID 1 and all subsequent chained ADATs to
device IDs 2, 3, and so on. For more information,
see “Connecting ADATs” on page 14 and “Setting
MMC device ID’s” on page 132.
Running ADATs at 44.1 kHz
To run an ADAT or ADAT XT at 44.1 kHz instead
of 48kHz, just set the desired sample rate on the
front panel of the MIDI Timepiece AV. Please note,
however, that when you choose 44.1 kHz, there will
be no indication on the ADAT front panel that it is
running at 44.1 kHz. Furthermore, the SMTPE
display on the ADAT front panel will not match the
SMPTE display in the MIDI Timepiece AV front-
panel LCD (or the rest of your MIDI Timepiece
AV-based system). This discrepancy, however, is
only a display issue: when you actually play music,
the music on the ADAT will be in perfect time with
the MIDI Timepiece AV (and everything else being
synchronized by the MIDI Timepiece AV). Please
contact Alesis for information about the
availability of a ROM update that addresses this
issue. Please note that this display discrepancy does
not occur when the ADAT or ADAT XT is running
at 48K.
Working with ADATs and the 2408
MOTU’s 2408 cross-platform audio interface for
provides a fiber-optic, 24-channel digital super-
highway between your ADATs and your 2408-
compatible audio software. The 2408 system
includes both word clock and ADAT SYNC ports
for clean, phased locked — and even sample-
accurate — digital audio transfers from ADATs to
the computer. For details, see the next section.
SLAVING A MOTU 2408 SYSTEM
The MIDI Timepiece AV provides complete
synchronization services for a MOTU 2408 (or
related) hard disk recording system. The AV can
continuously resolve the 2408 to video, SMPTE
time code or its own internal clock. This allows you
to slave the 2408 system to video, multi-track tape
decks, other hard disk recorders and any other
SMPTE time code source. If you have ADATs, the
AV provides ADAT sync to the 2408 and the
ADATs, allowing you to make sample-accurate
transfers between your ADATs and ASIO 2.0
compliant audio software.
ADAT Sync versus Word Clock
There are two ways to slave a MOTU 2408 system
to the MIDI Timepiece AV:
■
via ADAT Sync
■
via Word Clock
While there are several possible scenarios, we
recommend ADAT sync if you have an ADAT and
word clock otherwise.
!USB Interfaces Manual Book Page 122 Tuesday, October 10, 2000 12:43 PM