Handbook
16
Redbox User Handbook No 2
MATCHING CONVERTERS - RB-LI2
5 RB-LI2 Stereo Line Isolation Unit
Introduction
Fig 5-1: RB-LI2 Front Panel.
The RB-LI2 stereo line isolation unit is used to isolate audio signals from inter area ground
hum loops, which could be caused by equipment being powered by dierent mains power
supplies, or dierent phases on the same supply. The input and output are connected
together through a transformer, which has internal jumpers allowing the outputs to be
balanced about ground.
There is also a loop-through output, so that the RB-LI2 can be inserted into a line, forming a
transformer balanced distribution point.
This unit is useful where audio is required to be driven over a relatively long length of cable.
By isolating the signal using transformers, ground loop currents that can be present in non-
isolated signals, are eradicated completely.
System Block Diagram
Fig 5-2: RB-LI2 System Block Diagram.
MATCHING CONVERTERS
5
Gain
Input
Isolated Output
Transformer Balanced Mode
Ground Link
Jumper
Loop
Output
X2