Installation guide

TDM Installation Guide38
Connecting Equipment with
Digital Audio Ins and Outs
Because the 888/24 I/O, 882/20 I/O, 1622 I/O,
and ADAT Bridge I/O feature digital inputs and
outputs, Pro Tools allows you to digitally record
to or from a digital device such as a DAT re-
corder. The 888/24 I/O and ADAT Bridge I/O
provide both AES/EBU and S/PDIF digital audio
input and output. The 882/20 I/O and 1622 I/O
provide S/PDIF digital audio input and output.
If you plan to use a DAT player, CD recorder, or
other digital input and output device with your
Pro Tools system, be sure the external device
supports either the AES/EBU or S/PDIF format.
Your interface’s AES/EBU inputs and outputs
should only be connected to another AES/EBU
device. Likewise, its S/PDIF inputs and outputs
should only be connected to another S/PDIF de-
vice.
To connect your Pro Tools system to a DAT
recorder:
1 Connect the digital output of the audio inter-
face to the digital input of the DAT deck. Audio
channels 1 and 2 will be sent out of these out-
puts.
2 Connect the digital output of the DAT to the
digital input of the audio interface. The DAT re-
corder will be routed to Pro Tools inputs 1 and 2.
Connecting Effects Units
The 888/24 I/O, 882/20 I/O, 1622 I/O, and
ADAT Bridge I/O audio interfaces allow you to
connect effects units to your system by using
any analog (or digital) inputs/outputs as Auxil-
iary Inputs/Outputs for effects sends and re-
turns. Once an effects unit is attached this way,
you can send a variable amount of a track’s out-
put to the effects unit using a send fader in
Pro Tools.
Five separate send controls on each Pro Tools
track allow you to route audio to any of the
available outputs connected to your system or
through any of the 32-internal busses in the
Pro Tools TDM Mixer. Outputs can be returned
to mono or stereo Auxiliary Inputs for auto-
mated mixing or processing.
When you are using an effect in this send-type
of configuration, make sure the unit’s internal
mix or balance between direct (unprocessed)
and wet (effected) signal is set so that only the
processed signal is returned to Pro Tools. On
most effect units, a balance setting of 100%
(completely wet) is the appropriate setting.
If you’ve been using an effects unit in an instru-
ment setup, such as a guitar effects rack, you’ll
probably find the balance to be below 50%. If
the unit has separate dry and effect level knobs,
turn dry level control off. If you don’t do this,
the dry, unprocessed signal will be present in an
effect’s output along with the desired processed
sound, and you’ll have trouble accurately con-
trolling the effect balance in your final mix.
Connecting Effects Units Digitally
To use your audio interface’s inputs and outputs
as effects sends & returns to a digital effects de-
vice, set your interface to Internal mode (unless
it is already synchronized to an external clock
TDM_Install.book Page 38 Saturday, January 13, 2001 9:35 PM