Sonifex RB-MA2 Dual Microphone Amplifier

Description

The Sonifex RB-MA2 consists of two independent low-noise microphone pre-amplifiers for converting mic level signals to line level, or for driving long lines from microphones to processing equipment.

 

All connections and controls are on the rear panel. The microphone inputs are XLR-3 type and are electronically balanced. The input gain for each input can be adjusted individually by a recessed pre-set potentiometer which allows for the use of both dynamic and powered microphones.

The XLR-3 line outputs are 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 microphones.

 

 

 

RB-MA2 Block Diagram.

 

 

 

 

 

Technical Specification For RB-MA2
Audio Specification
Maximum Input Level:	-10dBu
Maximum Output Level:	+28dBu
Low Frequency Roll-Off:	125Hz @ 6dB/octave
E.I.N.:	130dB
Common Mode Rejection:	>60dB typically
Frequency Response:	20Hz to 20kHz ±0.1dB (600Ω load, ref 1kHz)
Input Impedance:	2kΩ nominal balanced
Output Impedance:	<50Ω
Gain Range:	Adjustable 36dB to 75dB gain (each input)
Distortion:	0.01% THD @ 1kHz, ref +8dBu output
Phantom Power:	48V
Connections
Input:	2 x XLR 3 pin female (Balanced)
Output:	2 x XLR 3 pin male (Balanced, can be unbalanced)
Mains Input:	Filtered IEC, switchable 110-120V, or 220-240V, fused, 6W max
Fuse Rating:	Anti-surge fuse 100mA 20 x 5mm (230VAC) Anti-surge fuse 250mA 20 x 5mm (115VAC)
Equipment Type
RB-MA2:	Dual microphone amplifier
Physical Specification
Dimensions (Raw):	28cm (W) x 10.8cm (D) x 4.2cm (H) (1U) 11” (W) x 4.3” (D) x 1.7” (H) (1U)
Dimensions (Boxed):	36cm (W) x 20.5cm (D) x 6cm (H) 14.2” (W) x 8” (D) x 2.4” (H)
Weight:	Nett: 1.00kg Gross: 1.45kg Nett: 2.2lbs  Gross: 3.2lbs