DUCK
SENSITIVITY
MIC
LEVEL
pwr
MIC
LINE
RELEASE
TIME
DUCK
DEPTH
phantom
pwr
15 VDC
+
-
INPUT
INPUT
INPUT
MIC
AUX
LINE
OUTPUT
DU30b
AUDIO DUCKER
Mic
Preamp
fast
slow
-6 dB -70 dB
www.rolls.com
ON
DUCK DEPTH: Adjusts the amount
of background signal (or Line In)
reduction - fully counter clockwise
the signal is reduced 6 dB, fully
clockwise the signal is reduced 70
dB.
PHANTOM PWR: Switch for
engaging the +15 volt phantom
power to the microphone input .
RELEASE TIME: Adjusts the
amount of time for the
“ducked” signal to return to
its normal level. Counter-
clockwise; slow - Clockwise;
fast.
MIC/LINE: When
pressed in, the gain
of the XLR Mic In is
reduced by 30 dB.
OUTPUT: Stereo RCA jacks
for connection to the sys-
tem’s amplifiers.
DUCK SENSITIVITY: The Threshold at which
“ducking” begins. When the microphone level
reaches the threshold, the signal present at
the Line In jacks is reduced until the an-
nouncement is over, then the Line In signal
returns to its previous level.
DC jack for connection to
the included Rolls PS27s
power supply
MIC IN: Female XLR jack for
connection to a dynamic or
condenser paging micro-
phone.
LINE IN: Stereo RCA jack
for connection to the
stereo signal source to be
“ducked” such as a tuner,
CD player or cassette
player.
AUX IN: Stereo RCA
jacks for connecting
to a source different
from the Mic In as
the master signal.
MIC LEVEL: Adjusts
the amount of gain
in the Mic In circuit.
A NOTE ON THE DU30b THRESHOLD, WITH THE SEN-
SITIVITY CONTROL FULLY CLOCKWISE: If the control
(paging) signal is on the XLR input, then ducking
begins (the threshold is) at -40 dB when the Mic/
Line switch is set to “Mic”, and 0 dB when the switch
is set to “Line”. If the control signal is on the RCA
input, ducking begins at -40 dB.
WE RECOMMEND TURNING THE DUCK SENSITIVITY AND DUCK DEPTH
KNOBS BOTH FULLY CLOCKWISE (ALL THE WAY UP) TO START. THIS IS THE
HIGHEST SENSITIVITY AND MOST DUCKING AVAILABLE ON THE UNIT.
