Loudspeaker Load and Output Distribution Compatibility
The Ahuja SSA-250DP public address mixer power amplifier is engineered to interface with both low-impedance loudspeaker configurations and high-voltage distributed line audio networks. The rear-panel terminal strip supports direct low-impedance loads rated at 4Ω and 8Ω for close-proximity sound reinforcement arrays, as well as 70V and 100V constant-voltage outputs designed for distributed commercial paging installations.
When deploying 70V or 100V speaker lines across industrial plants, auditoriums, educational institutions, or commercial facilities, the amplifier matches seamlessly with ceiling speakers, sound columns, and projection horns equipped with step-down Line Matching Transformers (LMT). To protect high-frequency horn driver diaphragms from low-frequency mechanical overload, the amplifier integrates a dedicated Box Speaker / Driver Unit selector switch. Setting the switch to the Driver Unit position defeats the internal bass boost (+10dB at 100Hz), tailoring the output spectrum for driver units and horn arrays.
Input Transducer and Audio Source Integration
The front and rear mixing sections provide extensive source compatibility across standard line-level devices and professional dynamic microphones:
- Microphone Channels: Six dedicated microphone input channels with an input sensitivity of 0.65mV and an input impedance of 4.7kΩ, accepting low-impedance balanced and unbalanced dynamic microphones.
- Auxiliary Inputs: Two auxiliary inputs (Aux-1 and Aux-2) rated at 100mV sensitivity with a 470kΩ input impedance, compatible with external media players, tuners, and standard consumer line-level equipment.
- Direct Line Input: A dedicated 1V / 50kΩ Line Input allows the SSA-250DP to function purely as a slave power amplifier when driven by the master output of an external PA mixing console or another audio processor.
- Digital Media & Wireless Connectivity: An onboard digital audio playback module supports direct file streaming from USB flash memory drives, SD/MMC storage cards, and wireless Bluetooth-enabled transmitting devices.
Amplifier Linking and Signal Distribution
For scalable sound reinforcement architectures requiring distributed amplification, the SSA-250DP provides dedicated preamplifier and line-level outputs:
- Preamplifier Output: Rated at 200mV into 600Ω, allowing the mixed input signal (including tone shaping from the ±10dB Bass and Treble controls) to be routed to signal processors or secondary distribution mixers.
- Line Output: Rated at 1V into 1kΩ, engineered specifically for daisy-chaining downstream high-power booster amplifiers or feeding high-fidelity audio recording equipment without loading the master preamplification stage.
Power Infrastructure and Backup DC Operation
The amplifier is compatible with standard utility AC mains supplies rated at 220–240V AC at 50/60Hz with a nominal operating power consumption of 460VA. For critical life-safety, paging, and industrial communication systems that demand uninterrupted operation during utility grid failures, the power section includes a 24V DC backup input. This input interfaces with two external 12V car batteries (they are not included) configured in series (drawing up to 6A DC at full output), with built-in circuitry providing instantaneous, automatic transfer to battery power if AC mains voltage is interrupted.
