The Rolls DU30b is an amazing microphone and background music preamplifier. When you make an announcement into the microphone, it automatically lowers the music volume during the announcement and then restores it to the previous level. It's a great choice for restaurants and small clubs. The mic preamp is clean and quiet. Key features include automatic music ducking during announcements. Technical specs: Input Impedance is 100K Ohms unbalanced and 600 Ohms balanced. Frequency Response ranges from 20 Hz to 40 kHz. THD + Noise is typically < 0.03%. Noise Floor is -78 dB. It has a Power LED indicator. Input/Output jacks are XLR balanced Input and RCA unbalanced input and output. It measures 4' x 4' x 1.5' and weighs 1 lb. (.5 kg). It runs on 12 - 16 VDC 50mA with a 5 x 1.2 mm DC Jack - Center Negative.
Using the Rolls DU30b is easy. First, connect your microphone to the XLR balanced input and your audio source and output devices to the RCA unbalanced input and output. Then, power it on using a 12 - 16 VDC 50mA power supply with the 5 x 1.2 mm DC Jack - Center Negative. When you start speaking into the microphone, the music will automatically lower in volume and go back up when you stop. Remember to place it in a clean and dry area. Avoid exposing it to extreme temperatures or humidity. For maintenance, simply wipe it with a dry cloth regularly to keep it clean. If you encounter any problems, check the connections and power supply first.
