8
LI0083 – Revision 22 June 2017
Microphone Conditioner Section
These LEDs indicate the current preamplifier-input status which is controlled via the
USB
inter-
face connection on the rear panel.
Mic OutAmp InAmp Out
Cu
rrent Out
+20dB +30dB +40dB +50dB
Monitor
Microphone Conditioner
Overload
High
Pass
20
0V
olt
CCP
-20dB -10dB 0dB +1
0dB
Overload
AC Coupled Mute
Amplifier
Overload
0dB +20dB
Current
G.R.A.S. Sound & Vibration
Power Module Type 12 AU
Gain
Gain
Gain
Output
0dB +1
0dB
Power On
I
O
Gain
LEDs
.
Indicates current gain setting.
Gain settings are from 0 dB to + 50 dB in
10 dB steps.
Input
Overload
LED. Lit when
microphone signal overloads the 12AU.
Overloads can be latched and read via
the
USB
interface, in which case they are
cleared when read. Alternatively, overload
messages can be signalled to remote con-
trol, displayed briefly and cleared automati-
cally.
High Pass
(20 Hz) LED. Lit when high-pass
filter is active. Otherwise, full-bandwidth
conditions apply, i.e. 1 Hz to 100 kHz
(– 3 dB). When fast settling is enabled, the
High Pass LED will flash during settling.
200 V
LED Lit when then 200 V Polariza-
tion is enabled.
CCP
LED. Lit when the CCP input is ena-
bled.