Specifications
192 I/O Guide22
Check the owner’s manual for your mixer,
power amplifier or effects processor to see if it
can handle this load. If the other devices in your
studio cannot handle this load, consider lower-
ing the headroom value of Pro Tools.
Output Trims
18 dB and 20 dB Output Levels
The 192 I/O has two Output Trims for each out-
put signal. You can switch between these Out-
put Trim levels in software. Output Trim A is
factory calibrated for 18 dB headroom. Output
Trim B is calibrated for 20 dB headroom. If you
want to change the inputs to 20 dB headroom,
switch the Output Trims to B and follow the di-
rections in the Pro Tools Reference Guide for Cali-
bration mode.
About Input Operating Levels
As with Output levels, check the owner’s man-
ual for your mixer, power amplifier or effects
processor to see if it operates more comfortably
at line level, in which case consider setting the
192 I/O to operate at –10 dBV line levels and/or
adjusting the Input Trims.
Consider the following when connecting a
mixer:
◆ If your mixer cannot handle more than 1.5V
(RMS) inputs at +4 dBu, then you should set the
192 I/O to operate at –10 dBV line level.
◆ If your mixer can handle up to 15.5V (RMS)
inputs, or has pads or attenuators on its inputs,
then you can use the +4 dBu setting on the
192 I/O.
◆ 192 I/O is calibrated for 18 dB headroom at
the +4 dBu setting.
Most manuals contain device input specifica-
tions, including whether or not there are pads or
attenuators. Consult the manufacturer’s docu-
mentation for your mixer or power amplifier for
further information.
Selecting Analog Input Operating
Levels
If you want to switch the input levels of the
192 I/O from +4 dBu to –10 dBV, you can access
these parameters, on a channel-by-channel ba-
sis, in the Hardware Setup dialog.
To Set Input Operating Levels:
1 Launch Pro Tools.
2 Choose Setups > Hardware Setup in Pro Tools.
3 If your 192 I/O is not the only peripheral, se-
lect it from the Peripherals list.
4 Click on the Analog In tab.
5 Select the input operating levels for each
channel.
6 Click OK to leave the Hardware Setup dialog.
Selecting +4 dBu or –10 dBV levels in the Hardware
Setup Dialog