Manual

Table Of Contents
Chapter 1 - RB-MA1 Single & RB-MA2 Dual Microphone Amplifiers
Redbox User Handbook 1-1
1. RB-MA1 Single & RB-MA2 Dual
Microphone Amplifiers
1.1. Introduction
Fig 1-1: RB-MA1 & RB-MA2 Front Panel
The RB-MA1 consists of an independent low-noise microphone pre-amplifier for
converting microphone level signals to line level, or for driving long lines from
microphones to mixing equipment. The RB-MA2 dual microphone amplifier consists of
two low noise pre amplifiers.
All connections and controls are on the rear panel. The microphone input is XLR-3
type and is electronically balanced. The input gain can be adjusted individually by a
recessed pre-set potentiometer.
The XLR-3 line output is electronically balanced and can be wired unbalanced by
grounding the non-phase signal, allowing you to feed both balanced and unbalanced
equipment.
For each channel there are independent switches to control a high pass filter (low
frequency roll-off at 125Hz) and to provide phantom power at +48V to the connected
microphone. An LED power indicator on the front panel displays the power supply
connection.
The rest of this chapter will refer to both RB-MA1 and RB-MA2 unless stated
otherwise.