Manual

Chapter 8 - RB-DMA2 Dual Digital Microphone Amplifier
Redbox User Handbook 8-3
8.3. Front Panel Indicators & Controls
Fig 8-3: RB-DMA2 Front Panel
8.3.1. Sync & Power Indicator
The LED on the front panel is normally red to indicate that power is present on the
unit. However, it also has a secondary role to indicate the status of the digital inputs:
Fast flashing between red and amber indicates a loss of digital input signal, or that
the unit is being calibrated.
8.3.2. Input Level Adjustment
Front panel potentiometers, coarse and fine, allow for adjustment of the gain of each
microphone input. The recessed screw-head potentiometer coarse control provides a
total gain range of 44dB, with the level knob fine control providing a ±12dB
adjustment.
Connect the mic input and adjust the gain until the line output is at the level that you
need. The wide gain range allows the use of both dynamic and powered microphones.
8.3.3. Disabling the Fine Gain Control Knob
Each fine control also has the ability to be disabled via a jumper (JP1 for MIC1 and
JP2 for MIC2) situated on the PCB. When the jumper is fitted the control is enabled.
JP2
JP1
Fig 8-4: Jumpers to Disable Fine Gain Control
RB-DMA2
DIGITAL MICROPHONE AMPLIFIER
LEVEL 1
LEVEL 2
++
8.3.1
8.3.2 8.3.4