FBT MPU - Manual (Page 23)

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INPUT WIRING
1) Use only shielded cables for all input connections. Cables with shielding films or with
high density braids are better. The cables shielded using twisted strands, even though
extremely flexible, can be damaged over time and can cause noise problems.
2) If possible, do not use unbalanced lines; if they must be used, cables shall be as short as
possible.
3) Before changing the connectors or the input cables, turn the amplifier level control to the
minimum position (anticlockwise).
4) Before changing the output connections, turn the amplifier level to the minimum and
switch off the AC power supply tominimize the possibility of short-circuits on outputs.
DISTRIBUITED SPEAKER SYSTEMS
The distributed speaker systems for music and paging are often used in hotels, restaurants,
offices, schools, etc. In these systems several speakers are located all over the area.
These multispeaker systems include one amplifier or one amplification channel that drives
one ormorespeakers equipped with transformers.
The transformers reduce the line voltage to a lower level, so to drive speakers, and are
connected between the conductor pair. Compared to a single speaker, the combination of a
transformer and a speaker on the line has a much higher impedance toward the amplifier,
and this makes it possible to add several speakers to a single power signal line.
POWER AMPLIFIER
100V
100V
UK
CONNECTIONS
Standard distributed speaker system