Communications Systems | PRS‑xPxxx and LBB 4428/00 Power Amplifiers
PRS‑xPxxx and LBB 4428/00 Power
Amplifiers
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1, 2, 4, or 8 audio outputs (selection from 100 / 70 /
50 V outputs)
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Audio processing and delay for each amplifier
channel
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Amplifier supervision and spare amplifier switching
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Loudspeaker line and loudspeaker supervision
(LBB 4428/00 only line supervision)
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Eight control inputs and 1, 2, 4 or 8 control outputs
There are four types of Power Amplifier units in the
Praesideo product range. These differ in the number of
amplifier channels per frame: one, two, four, or eight.
The overall power rating is 500 watts for all of the
amplifiers.
The Power Amplifiers can be set to 100 V, 70 V and
50 V output tappings. They have short-to-ground and
short-circuit detection functions, and can generate
their own pilot tone for supervision purposes.
Functions
The Power Amplifiers receive input signals over the
network. They also have two auxiliary audio inputs
(four for LBB 4428/00) for local audio. Their eight
control inputs are freely programmable for system
actions, and priorities can be assigned to these inputs.
Each control input has the ability to monitor the
attached line for open and short-circuits. Control
outputs are freely programmable for faults and call
related actions.
The 2 x 16‑character display and the rotary control
enable local status enquiries. The display shows the
VU‑meter reading, when the audio monitoring mode is
active. Audio can be monitored by headphone.
The units are self-monitoring and continually report
their status to the network controller. They support
both single branch and redundant loop cabling. The
amplifiers have a changeover facility for spare power
amplifier switching. Changeover relays are included
with the units. The amplifiers have a 48 V DC back-up
supply input.
The digital audio processing can handle three
parametric equalization sections and two shelving
equalization sections per channel with configurable
audio delay.
Controls and indicators
• 2 x 16-character LCD for status display
• Rotary/push control button
• Mains switch
• Voltage selector for PRS‑xPxxx