Bosch LBD1938/00 – Plena Booster 480W Power Amplifier

Bosch LBD1938/00 – 480W Plena Booster Power Amplifier

The LBD1938/00 is a powerful power amplifier in a 3U housing for rack mounting or tabletop use. The Bosch Plena power amplifier series with its varied amplification range fulfills a wide variety of public address requirements at a surprisingly low cost.

System overview

The LBD1938/00 amplifier features a colorful LED bar on the front side to indicate the acoustic level of the signal in dB. The LBD1938/00 amplifier has a 100 V input for slave operation of the amplifier, XLR loop in and loop through facility for ease of installation and a 100 V output as well as 70 V output for connecting to the loudspeakers with line matching transformers, 8 ohm and 4 ohm outputs for connecting to the Low impedance speakers. The output voltage can be selected between 100 V and 70 V internally.

The LBD1938/00 amplifier features a dual XLR inputs with priority switching. Gain or level control is located on the rear of the unit to avoid accidental setting change. The amplifier works on 24 VDC power supply during emergency situations.

Functions

Dependability:

The amplifier is protected against overload and short circuits. A temperature-controlled fan ensures high reliability at high output levels and low acoustic noise at lower output levels. An overheat protection circuit switches off the power stage, if the internal temperature reaches a critical limit due to poor ventilation or overload.

Input:

The system has two balanced inputs with priority control, each with a loop-through facility. This makes it easy to connect remote systems that require priority control. An additional 100 V line input is provided to connect the amplifier to a 100 V loudspeaker line to provide more power to remote locations.
Gain or level control is located on the rear of the unit to avoid accidental setting change. A meter with LEDbar shows the output level.

Output:

The amplifier has 70 V and 100 V outputs for constant voltage loudspeaker systems, and a low impedance output for 8 ohm or 4 ohm loudspeaker loads.
There are Priority input enable and Program input enable pins which are default off and default on respectively, when these enabled by a 24 VDC signal then the respective inputs are activated. Whenever the priority enable input is supplied with continuous 24 VDC signal, the program input is over-rided by the priority input.