User Manual

PRE Guide6
Activity LED
When lit (green), this LED indicates MIDI data is
being received by PRE.
Remote “Lock-Out” LED
When lit (green), this LED indicates PRE is in Re-
mote Lock-Out mode. In this mode, PRE is con-
nected to a remote controller (such as Pro Tools
or a dedicated device), and the front panel con-
trols are locked out.
PRE is placed in Remote Lock-Out mode (after
configuring PRE for remote control) by selecting
Remote Lock-Out Mode in the Mic Preamps tab
of the Pro Tools Peripherals dialog.
PRE can be taken out of Remote Lock-Out mode
by deselecting the Remote Lock-Out Mode box
in the Pro Tools Peripherals dialog, or by power-
ing PRE off, and then back on.
For more information on locking and unlocking
PRE front panel controls, see Chapter 3, “Re-
mote Operation.”
Shift Switch and LED
This switch (along with the channel Select
switches) is used in Stand-alone mode when
grouping channels in order to control multiple
channels simultaneously. When lit (green), this
LED indicates the Shift switch is active.
OSC (Oscillator) Switch and LED
This switch enables the internal oscillator,
which can be used for calibrating the inputs of
audio interfaces (such as the HD I/O). When lit,
the OSC LED indicates the oscillator is on.
The oscillator generates a fixed tone of approxi-
mately 1k Hz at +4 dBu (= 1.228 Vrms).
The PRE oscillator signal can be routed through
the OSC output on the back of the unit or
through individual channels on the DB-25
connector.
To route the signal to the OSC output:
 Press the OSC switch on the front of the unit.
To route the signal through an individual channel
output on the DB-25 connector:
1 Disconnect any cable inserted into the chan-
nel’s Send jack.
2 Enable the Insert for that channel via the front
panel (see “Insert Switch and LEDs” on page 9)
or through software.
3 Press the OSC switch on the front of the unit.
The oscillator signal can only be activated via
the front panel. However, routing the oscillator
signal through the DB-25 connector can be con-
trolled remotely or by the front panel.
Calibration can change with temperature.
The output is nominally +4 dBu, but may
vary up to ± 0.3 dB depending upon the
current operating temperature. Allow the unit
to warm up and stabilize the oscillator output
before using it for calibration purposes.
Oscillator routing through a channel output
is done after the channel’s metering point,
and therefore does not display in the PRE
meters.