General
Number of channels	4
Power per channel	120 W (sinus)
Rack format	19˝
Height in rack	3 HE
Application range	Professional ELA systems
Supported technology	100 V, 50 V, 25 V
Inputs	4 electronically balanced program inputs, 4 priority inputs
Pilot tone modules	Prepared for FD-20
LED indicators	variously-coloured indicator lamps
Fault alarm contacts
Short-circuit and no-load safe
Power Remote
Soft-start
Ground/Lift switch

The RCS Audio-Systems BA-4120DP is a 4-channel power amplifier in 19˝ rack format, specifically designed for use in professional ELA systems (Electronic Loudspeaker Systems). It supports high-voltage technologies 100 V, 50 V, and 25 V, commonly used in large installations such as buildings, industrial facilities, or transportation systems. The amplifiers are fully monitored and feature fault alarm contacts for all functions relevant in emergency situations, ensuring reliable alarm and monitoring functionality. The devices are designed for continuous operation, short-circuit and no-load safe, and equipped with appropriate fuse protection.

Applications

The BA-4120DP is suitable for professional sound systems, particularly in buildings requiring emergency call or mandatory announcement functions. The support for 100 V, 50 V, and 25 V technology enables driving various loudspeaker impedances over long cable runs, which is necessary in large areas or multi-storey buildings. The integrated fault alarm contacts ensure that in case of a fault or disturbance, an external alarm system can be activated.

Functions and Equipment in Detail

Each amplifier features four electronically balanced audio inputs for program signals and four additional priority inputs, which can be used for mandatory announcements. This priority function allows important messages (e.g., during evacuation) to interrupt ongoing music or other programs. The devices can be equipped with up to four pilot tone modules (FD-20) to monitor the amplifier’s function. Inputs and outputs are implemented using screw terminals, reducing wiring effort and eliminating the need for XLR connectors.

Technology Explained Simply

The electronic balancing of inputs and outputs minimizes hum interference caused by ground loops. This improves signal quality and reduces unwanted noise. The LED indicator lights on the front panel, in various colors, continuously display the amplifier’s operating status, such as operation, fault, or overload. A Power Remote contact enables remote switching of the device, even if the local on/off switch is turned off. The soft-start mechanism and a special circuit suppress unpleasant switching noises, protecting the acoustics in sensitive environments. A Ground/Lift switch disconnects the connection between chassis ground and signal ground to avoid hum loops.

Compatibility and Accessories

The amplifier is prepared for mounting of pilot tone modules FD-20, which serve to monitor the amplifier’s function. Compatibility with the mentioned high-voltage technologies (100 V, 50 V, 25 V) enables integration into existing sound networks. The use of screw terminals for inputs and outputs simplifies installation and maintenance.

Mounting and Installation

The BA-4120DP is designed in 19˝ rack format (3 HE), making it suitable for standard rack systems. Installation is done by mounting into an appropriate rack, with screw terminals enabling quick and secure wiring. The devices are designed for continuous operation and require no special environmental conditions other than sufficient ventilation.

Operational Advantages

The combination of high-voltage technology, priority inputs, fault alarm contacts, and integrated monitoring makes the BA-4120DP a robust and reliable component in professional sound systems. The reduction of hum and noise interference through balancing and the Ground/Lift switch ensures clear sound quality. Remote control via Power Remote and visual status indication through LED lights facilitate maintenance and monitoring during operation.