OWNERS MANUAL
DU30
Mic Preamp / Audio Ducker
Rolls Corporation
Salt Lake City, UT
9/01
LIMITED WARRANTY
This product is warranted to the original consumer purchaser to
be free from defects in materials and workmanship under normal installa-
tion, use and service for a period of one (1) year from the date of purchase
as shown on the purchaser’s receipt.
The obligation of Rolls Corporation under this warranty shall be
limited to repair or replacement (at our option), during the warranty period
of any part which proves defective in material or workmanship under nor-
mal installation, use and service, provided the product is returned to Rolls
Corporation, TRANSPORTATION CHARGES PREPAID. Products returned
to us or to an authorized Service Center must be accompanied by a copy of
the purchase receipt. In the absence of such purchase receipt, the warranty
period shall be one (1) year from the date of manufacture.
This warranty shall be invalid if the product is damaged as a
result of defacement, misuse, abuse, neglect, accident, destruction or alter-
ation of the serial number, improper electrical voltages or currents, repair,
alteration or maintenance by any person or party other than our own service
facility or an authorized Service Center, or any use violative of instructions
furnished by us.
This one-year warranty is in lieu of all expressed warranties, ob-
ligations or liabilities. ANY IMPLIED WARRANTIES, OBLIGATIONS,
OR LIABILITIES, INCLUDING BUT NOT LIMITED TO THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PAR-
TICULAR PURPOSE, SHALL BE LIMITED IN DURATION TO THE ONE
YEAR DURATION OF THIS WRITTEN LIMITED WARRANTY. Some
states do not allow limitations on how long an implied warranty lasts, so
the above limitation may not apply to you.
IN NO EVENT SHALL WE BE LIABLE FOR ANY SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR BREACH OF
THIS OR ANY OTHER WARRANTY, EXPRESSED OR IMPLIED,
WHATSOEVER. Some states do not allow the exclusion or limitation of
special, incidental or consequential damages so the above limitation or ex-
clusion may not apply to you. This warranty gives you specific legal rights,
and you may also have other rights which vary from state to state.
DU30 MIC PRE - DUCKER
•
Automatically ducks music under announcements
• Perfect for restaurants and small clubs
• Clean, Quiet Mic Preamp
The DU30 is a microphone preamp and back-
ground music preamp. When an announcement is
made into the microphone, the music is automati-
cally "ducked" under the announcement. Then the
music is brought back to it's previous l level.
phan
pwr
12 VDC
PAD SENSITIVITY
MIC
LEVEL
PWR
DU30
+
-
INPUTINPUT INPUT
MIC AUX LINE
OUTPUT
AUDIO DUCKER
Mic
Preamp
Thank you for your purchase of the Rolls DU30 Mic Preamp Audio Ducker. This
device temporarily and automatically mutes or "ducks" a background music signal
under an announcement. After the announcement, the music level is automatically
returned to it's previous level.
DESCRIPTION
REAR PANEL
MIC IN: Female XLR jack for connection to a dynamic or condenser paging micro-
phone.
PHTM PWR: Jumper for engaging the +12 volt phantom power to the microphone
input. The Rolls 12 volt phantom power circuit will power 99% of the world's existing
condenser microphones.
ALT IN: Stereo RCA jacks for connecting to a source different from the Mic In as the
master signal.
LINE IN: Stereo RCA jack for connection to the stereo signal source to be "ducked"
such as a tuner, CD player or cassette player.
LINE OUT: Stereo RCA jacks for connection to the system's amplifiers.
FRONT PANEL
PAD: When pressed in, the gain of the XLR Mic In is reduced by 30 dB.
MIC LEVEL: Adjusts the amount of gain in the Mic In circuit.
SENSITIVITY: The Threshold at which "ducking" begins. When the microphone level
reaches the threshold, the signal present at the Line Ins jacks is reduced until the
announcement is over, then the Line In signal returns to its previous level.
OPERATION
Shown below is a diagram of typical connection for the DU30. Set the level of the
music signal for a comfortable level. Speak into the microphone and adjust the Mic
Level for a comfortable level, then adjust the Sensitivity so that the music is muted
when speaking with a normal voice.
SPECIFICATIONS
Frequency Response 20 Hz - 40 kHz
Input Impedance 100KW unbalanced, 600 W balanced
THD + Noise <0.03% typical
Noise Floor -78 dB
Indicators Power LED
Active LED
Input/Output jacks XLR balanced output
RCA unbalanced input and output
Size: 4" x 4" x 1.5"
Weight: 1 lb. (.5 kg)
Power: 12 - 16 VDC 50mA
5 x 1.2 mm DC Jack - Center Negative
SCHEMATIC
TUNE +
TUNE -
SET
PRESET
FM / AM
STEREO
/MONO
MUTE
STATION CALL
2 / 10
5 / 13
1 / 9
6 / 14 7 / 15
3 / 11 4 / 12
8 / 16
FREQUENCY
PRESET
SIGNAL
HEADPHONE
VOLU ME
HEADPHONE
OUT
ST
FM
MW
MUTE
MHz
kHz
AUTO
RS79
0 10
Paging Amplifier
phan
pwr
12 VDC
PAD SENSITIVITY
MIC
LEVEL
PWR
DU30
+
-
INPUTINPUT INPUT
MIC AUX LINE
OUTPUT
AUDIO DUCKER
Mic
Preamp
127-Sep-2001Date:
Rev:
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