MOTU PCI-424, Руководство пользователя

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P E R F O R M A N C E T I P S & T R O U B L E S H O O T I N G
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external sync (shown as “diG”) and internal sync
(“int”). Note that the ADAT will return to the “diG”
setting each time it is powered off.
Alesis ADAT track offset
If you find that sample accurate transfers from an
ADAT are displaced by a small amount, try to reset
the ADAT to its factory default state. This is
accomplished by powering on the ADAT while
holding down the RECORD and PLAY keys simul-
taneously. The ADAT LX uses a ‘soft’ power key so
LX users will have to unplug and plug the ADAT LX
while holding down the RECORD and PLAY keys.
Tascam TDIF and word clock
If any Tascam TDIF units are connected, they must
be word locked to the 2408mk3. The Tascam TDIF
protocol does not contain word clock, so you must
slave the Tascam to the 2408mk3’s word clock
output. For detailed instructions on how to
accomplish this, see “Syncing Tascam ‘TDIF’
devices” on page 49, “Syncing to a DA-88/98 time
code track” on page 47, or “Sample-accurate
Tascam sync” on page 42. Another alternative is to
slave everything to a Digital Timepiece. The
Tascam LED on the 2408mk3 will blink if a
connected Tascam device is not in sync.
Clicks and pops under word clock sync
Many problems result from incorrect word
clocking. It is essential that all digital devices in the
system be word locked. Consult chapter 4,
“Installing the PCI-424 Hardware” (page 27) for
detailed information on how to word clock your
gear. Whenever there is any weird noise or
distortion, suspect incorrect word lock. Tip: the
Cuemix Console provides messages helpful for
diagnosing problems and optimizing system
performance.
Clicks and pops due to PCI bandwidth problems
If your host audio software has a CPU meter, and it
is not overloaded, but you observe spiking in the
meter, you may be exceeding available PCI
bandwidth. This may happen if you have other PCI
cards installed and/or multiple MOTU audio I/Os.
To remedy this, you can disable unused inputs and
outputs in the MOTU PCI Audio Console. Also
check the CueMix console message center for
details about PCI bus performance.
Clicks and pops under ADAT Sync
Sometimes, the ADAT sync cable seems to be
plugged into the PCI-424 card, and partially works
- but it isn’t really all the way in because it binds
against the side of the bulkhead slot. This can cause
clicks when slaved to 424 ADAT. Make sure it is
really seated firmly. Connect the ADAT sync before
screwing the card down - this will ensure that it is
aligned properly.
Clicks and pops in 2408mk3 stand-alone mode
Any time the 2408mk3 is in stand alone mode, not
connected to the computer or the computer isn't
turned on, the 2408mk3 is acting as a stand alone
converter and has a number of choices for word
clock settings. If the 2408mk3 is ever trying to
clock to some digital source that isn't present, or
there are two sources present that are not word
clocked locked together, you have the possibility of
click's and pop's or sometimes white noise. This is
true in any digital scenario.
If the 2408mk3 is in stand alone mode and you
have not assigned it the correct clock setting or any
clock setting, it could just be sitting there trying to
look for word clock or ADAT clock. The solution is
to set the 2408mk3 to internal as the clock source
or choose the source you are working with. Let's
say you are using the analog I/O and a DAT
machine with the 2408mk3. In stand alone mode
you could choose internal, meaning the 2408mk3
is clocking internally and is the master, ready for
you to send audio to your DAT machine. You could
choose SPDIF as the clock source if you have the
DAT machine on and connected. The sample rate