The PB-400 Industry amplifier is an ultra-reliable, high-power, 4 channel (250W per channel) audio power amplifier designed for use in critical systems. It is designed to drive 100 V line loudspeaker systems and is equipped with on-board DSP allowing gain, EQ, delay and other parameters to be controlled from a remote location using WinControl software, via RS-485.
The amplifiers are fully monitored, with automatic fault detection and reporting. Inputs are via balanced analogue audio.
When used in conjunction with Duran Audio’s OpSTImizer® service the PB amplifiers can provide significant improvements in speech intelligibility within a tunnel.
The full complementary class AB amplifiers are equipped with rugged industrial power mosfet devices capable of handling large currents without risk of failure. The large phase margin within the feedback loop keeps the amplifiers stable under any load condition.
The IndustryAmps are equipped with a high-power switch mode power supply. The power supply is specially designed for audio applications, featuring soft knee over current protection and very high peak power capability. Active power factor correction keeps the mains harmonics at low levels while increasing the input voltage range from 90V to 270V without interruption or manual changeover. A low-power stand-by switch mode auxiliary supply enables shut down of the main supply under network control.
Signal Processing Unit
A digital signal processor unit controls the amplifier units. The digital processing is performed by a 32 bit floating point DSP. The DSP software provides various functions in order to attenuate, delay, equalize, filter, compress or limit the separate audio signals for all individual output channels, or perform special algorithms necessary for dedicated active array control. All software is stored in non-volatile memory, enabling the unit to start up and operate autonomous without host control unit.
Inputs and Outputs
All power-amplifier outputs are equipped with high-grade toroidal output transformers to provide 100V/70V outputs. All loudspeaker terminals are protected by means of gas discharge devices against voltage spikes. Both analogue audio inputs are transformer isolated.
The RISC also manages the network functionality of the device. By using a host PC, the user can monitor all surveillance related parameters, send "one line" control commands or upload new DSP code or process settings to any combination of addresses. All surveillance related and DSP related software inside the IndustryAmp is stored in non-volatile RAM, restoring the last settings automatically after power up.
The surveillance routines are performed by a RISC (reduced instruction set computer) which is located on the processor board. It monitors a large amount of surveillance related parameters. These include: pilot tone detection on all inputs, load monitoring on each output, temperatures of heat sink and ambient, amplifier functionality, fan speed, ambient noise sensing microphone presence and DSP status. The RISC software enables the IndustryAmp to take “intelligent” autonomous decisions such as switching to a second input channel in case a pilot tone is lost, or acoustical output level adaptation the to the ambient noise level without any central intervention. All possible reported failures can be mapped onto a dedicated failure relay.