Rolls DU30b Preamp Ducker Manual & Schematic 电路图.pdf

Rolls Corporation Salt Lake City, UT 9/05 DU30b DUCKER - Automatically ducks music under announcements - Perfect for restaurants and small clubs - Clean, Quiet Mic Preamp The DU30b is a microphone preamp and background music preamp. When an announcement is made into the microphone, the music is automatically “ducked” under the announcement. Then the music is brought back to its previous level. SPECIFICATIONS Frequency Response 20 Hz - 40 kHz Input Impedance 100K unbalanced, 600 balanced THD + Noise <0.03% typical Noise Floor -78 dB Indicators Power LED Input/Output jacks XLR balanced input 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 Thank you for your purchase of the Rolls DU30b Mic Preamp Audio Ducker. This device temporarily and automatically mutes or “ducks” a background music signal under a paging microphone or other auxil- iary signal. After the announcement, the music level is automatically returned to its previous level. DESCRIPTION REAR PANEL MIC IN: Female XLR jack for con- nection to a dynamic or condens- er paging microphone. PHTM PWR: Jumper for engag- ing the +12 volt phantom power to the microphone input - confi gured OFF from the factory. AUX 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. OUTPUT: Stereo RCA jacks for connection to the systems ampli- fi ers. 12 VDC: Power input. Connect to the enclosed Rolls PS27 AC adapter. FRONT PANEL MIC/LINE: When pressed in, the gain of the XLR Mic In is reduced by 30 dB. RELEASE TIME: Adjusts the amount of time for the “ducked” signal to return to its normal level. Counterclockwise; slow - Clock- wise; fast. MIC LEVEL: Adjusts the amount of gain in the Mic In circuit. DUCK SENSITIVITY: The Threshold at which “ducking” begins. When the microphone level reaches the threshold, the signal pres- ent at the Line In jacks is reduced until the announcement is over, then the Line In signal returns to its previous level. 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. WE RECOMEND TURNING THE DUCK SENSITIVITY AND DUCK DEPTH KNOBS BOTH FULLY CLOCKWISE (ALL THE WAY UP) TO START. THIS IS THE HIGHEST SENSI- TIVITY AND MOST DUCKING AVAILABLE ON THE UNIT. OPERATION If you are using a condenser microphone, carefully connect the two Phantom Power jumper pins together. Set the level of the music signal (Line In) 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. Set the Release Time control for the amount of time you wish for the Aux In signal to return to normal. Set the Duck Depth control for the amount of Aux In signal reduction you want when the Mic or Alternate signal is present. WARRANTY For information on the Rolls One Year Limited Warranty, and to register this product, visit our website at DU30B SCHEMATIC RadioFans.CN 收音机爱 好者资料库