General
Output power	375 W (Program) / 250 W (RMS)
Input sensitivity	1 V, 10 kOhm, symmetrical
Output voltage	100 V or 70 V
Frequency response	90 Hz to 20,000 Hz (better than -3 dB)
Signal-to-noise ratio	91 dB
Total harmonic distortion (THD) at 1 kHz	better than 0.29 %
AC power supply	230 V, 50–60 Hz
DC power supply	24 V (emergency power)
Power consumption (sine signal)	360 W
Power consumption (no load)	12 W
Power consumption (standby)	7,7 W
Height of housing	2 RU
Protection circuits	protection against no-load, short circuit, overtemperature, inrush delay
Cooling	Maintenance-free, fanless
Inputs	symmetrical, screw connector
Outputs	Speaker outputs, screw connectors
LED indicators	For signal and operating states
Standby mode	Automatic when signal is missing, max. 9.9 W
Response time from standby	30 ms
Optional input transformers	TSE-203 per input
Compliance with standards	IEC-268-5, VDE 0828/EN 60849

The RCS Audio-Systems DBA-250D is a digital 1-channel power amplifier for 100 V and 70 V systems, designed for professional use in sound systems, particularly in electronic alarm systems (ELA) according to VDE 0828/EN 60849. The amplifier features a high efficiency of over 90 %, which, compared to analogue power amplifiers with approximately 70 %, results in significantly lower waste heat. This reduces cooling requirements in 48,3 cm ( 19 inch )-technical rooms and extends the device's service life. Cooling is maintenance-free and fanless, preventing contamination and making the devices especially suitable for noise-sensitive environments such as offices, churches or conference rooms.

Applications

The DBA-250D is primarily designed for use in electronic alarm systems (ELA), with integrated pilot tone inputs and fault alarm contacts for backup power and amplifier meeting the requirements of such systems. The low installation depth of 260 mm and compact design in 2 RU enable flexible mounting in standard 48,3 cm ( 19 inch ) racks. The amplifiers are designed for continuous operation and are therefore also suitable for applications in public buildings, schools, hospitals or industrial facilities, where reliable and low-maintenance sound systems are required.

Functions and Equipment in Detail

The amplifier features symmetrical inputs and speaker outputs on screw terminals, reducing wiring effort and ensuring secure, interference-free signal transmission. The inputs can optionally be equipped with input transformers (TSE-203) to facilitate adaptation to various signal sources. The front panel is fitted with LED indicators displaying important operating and signal statuses. In the absence of a signal, the amplifier automatically switches to standby mode, with power consumption of maximum 9.9 W. When a signal is present, for example during alarms, the amplifier is operational within 30 ms.

Technology Explained Simply

The digital technology of the DBA-250D enables high efficiency and low power loss. The output power is 375 W (program) and 250 W (RMS), with output voltage adjustable to 100 V or 70 V. The frequency response curve is between 90 Hz and 20,000 Hz (better than -3 dB), enabling clear and wideband reproduction. The signal-to-noise ratio is 91 dB, and the total harmonic distortion (THD) is less than 0.29 % at 1 kHz. Protection circuits against no-load, short circuit, overheating, as well as a power-on delay, ensure safe operation. Power supply is via 230 V AC (50–60 Hz) or 24 V DC (backup power supply). Power consumption in sine signal operation is 360 W, in no-load 12 W, and in standby mode 7.7 W.

Compatibility and Accessories

The amplifier is designed for operation with 24 V DC backup power supplies, reducing battery capacity compared to analogue systems. Output power and protection circuits comply with IEC-268-5 standards. Optional input transformers TSE-203 can be added per input to enable adaptation to various signal sources. The devices are designed for use in 48,3 cm ( 19 inch ) racks and offer low installation depth, facilitating installation in confined spaces.

Mounting and Installation

Mounting is in a standard 48,3 cm ( 19 inch ) rack. The screw terminals at inputs and outputs allow for quick and secure wiring. The recessed volume controls on the front reduce the risk of damage and enable a clean front panel design. The maintenance-free cooling without fans reduces maintenance effort and noise emissions.

Advantages in Operation

The DBA-250D offers high efficiency, low waste heat and maintenance-free cooling, reducing operating costs and extending service life. The fast response time of 30 ms in standby mode ensures reliable alarm activation. Integrated protection functions and clear indication of operating statuses via LEDs simplify maintenance and diagnostics. The low installation depth and compact design enable flexible installation in existing systems.