Rb-Ssml1 Mic/Line Source Selector With Compressor Limiter; Introduction; Fig 4-1: Rb-Ssml1 Front Panel - Sonifex Redbox RB-SS10 User Handbook Manual

4 RB-SSML1 Mic/Line Source Selector with Compressor Limiter

Introduction

Fig 4-1: RB-SSML1 Front Panel.

The RB-SSML1 is a 1U rack-mountable source selector for compressing or limiting an
incoming microphone or stereo line signal and mixing this signal with a stereo monitor
input, which can then be metered and mixed to two headphone outputs. The unit is mainly
used in situations where level control is required, for example in voiceover applications.
The mic input consists of an independent low-noise microphone pre-amplifier for
converting microphone level signals to a line level. 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. A preset pot on the rear panel allows adjustment of the
mic gain from 36dB to 75dB.
A front panel switch selects between mic and line inputs. Both mic and line inputs have fully
adjustable volume control via front panel pots, with the line input having an additional 10dB
gain increase via a switch on the rear panel for use with unbalanced equipment. The mono
mic input is converted to a stereo signal before being passed to the compressor/limiter.
The XLR-3 stereo monitor input has an adjustable volume control via a back panel recessed
pot, and has an additional 10dB gain increase via a switch on the rear panel, for use with
unbalanced equipment. The audio on this input is only present on the headphone outputs,
and is therefore suitable as a return feed from a codec, a PC audio output, or similar
equipment.
The compression ratio and threshold limits of the compressor/limiter section are fully
adjustable via linear pots situated on the front panel. The threshold can be set between
-30dBu and +20dBu. When the input signal rises above the threshold level a soft-knee
compression is applied at the selected ratio. The compressor has an attack time of
approximately 20ms and a release time of approx 400ms, and can operate at ratios of 1:1
(no compression) to ∞:1 (limiting). A front panel BYPASS switch can be used, where no
compression is applied. A rear-panel DIPswitch allows compression only to be applied to the
mic input and not the stereo line input.
Redbox User Handbook No 3
MIXER & SOURCE SELEC TORS
Mic Line Threshold
Volume Volume Control
Mic/Line Bypass
Select Switch Switch
LED Metering
Headphone
Outputs
Compression
Control
4
Headphone
Volume
25