MOTU PCI-424, User Manual

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T R O U B L E S H O O T I N G
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Tascam sync” on page 40. 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 3,
“Installing the PCI-424 Hardware” (page 25) 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 Digital Performer or AudioDesk’s CPU meter is
not overloaded, but you encounter spiking in the
peak indicator, 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 standalone 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
on the 2408mk3 must match the sample rate of the
DAT. There are many possible configurations.
There must only be one master!
Clicks and pops due to hard drive problems
If you have checked your clock settings and PCI
bandwidth and you are still getting clicks and pops
in your audio, you may have a drive related
problem. Set your Clock Source to PCI-424
Internal and try recording just using the analog
inputs and outputs of your 2408mk3. If you
encounter the same artifacts you may want try
using another drive in your computer. Clicks and
pops can also occur when the drive is severely
fragmented, the disk drivers are outdated, or if you
are using a SCSI accelerator that is not optimally
configured for working with audio.
Connecting or powering gear during operation
It is not recommended that you connect/
disconnect, or power on/off devices connected to
the PCI-424 system while recording or playing
back audio. Doing so may cause a brief glitch in the
audio.