User guide

Avid Mbox Pro User Guide6
Soft Limit Switch
These switches engage a soft limiter on that chan-
nel, applying a smooth, overdriven tape-type lim-
iter to strong input signals.
Mic/Line Input Source Button
These buttons select the input source for input
channels 3 and 4. When “out”, the back panel Mic
input is active; when “in” the back panel Line In-
put is active for that channel.
LED Ladders (Inputs 1–4)
These four 8-segment LED ladder-style meters il-
luminate green in the presence of audio signal, and
illuminate red when the signal is about to clip
(overload) the input. The LEDs are associated with
signals routed from inputs 1–4.
48V Switch and LED (Phantom
Power)
The 48V switch toggles phantom power on/off for
all mic input channels. The LED, when lit, indi-
cates that 48V phantom power is active on the
XLR Mic inputs.
About Phantom Power
Most condenser microphones require phantom
power to operate. Dynamic microphones do not re-
quire phantom power to operate, but are not
harmed by it.
If you are not sure about the phantom power re-
quirements for your microphone, refer to your mi-
crophone’s documentation or contact the manufac-
turer.
Master Volume Knob
The Master Volume knob adjusts the output level
of the assigned Monitor output pair. The Master
Volume knob is assigned to an output pair (1–2,
3–4, or 5–6) in the Control Panel. See “Master
Vol” on page 31.
Dim/Mute Switch
The Dim/Mute switch affects the output volume
for control room outputs as assigned in the Driver
Control Panel setup (by default, Line outputs 1 and
2.) See “Control Room Assignment” on page 31.
The switch has two functions:
 When pushed, Line outputs 1 and 2 (or the cur-
rently assigned Control Room outputs) are
dimmed. When Dim is engaged, the switch
LED lights solid.
 When pushed and held in, Line outputs 1 and 2
(or the currently assigned Control Room out-
puts) are muted. When Mute is engaged, the
switch LED flashes.
Mono Switch
The Mono Button sums the control room outputs
to a mono signal (delivering that identical signal to
both speakers) via the Driver Control Panel or the
Mbox Pro. When engaged, the Mono LED lights.
Although phantom power can be used safely
with most microphones, it is possible to dam-
age some ribbon microphones with it. Always
turn off phantom power and wait at least ten
seconds before connecting or disconnecting
a ribbon microphone.
When using phantom power, the Mbox Pro
maximum current per microphone is 10 mA.