The Ahuja SSA-250M public address mixer amplifier is engineered for versatile integration across industrial, commercial, and institutional sound distribution networks. Designed to accommodate a wide variety of audio sources, loudspeaker loads, and secondary power infrastructure, the unit provides standardized electrical matching across both low-impedance setups and high-voltage distributed line systems.
Audio Source and Front-End Input Compatibility
The mixer amplifier features nine dedicated input paths engineered to interface directly with dynamic microphones, line-level media players, and upstream audio processing gear without requiring external impedance matching transformers:
- Microphone Inputs (Mic 1 to Mic 6): Rated at 0.65mV sensitivity with an input impedance of 4.7kΩ via standard 6.3mm phone jacks. These channels are compatible with standard low-impedance dynamic vocal and paging microphones.
- Auxiliary Inputs (Aux 1 and Aux 2): Rated at 100mV sensitivity with a 470kΩ input impedance, suitable for line-level audio sources including CD players, media playback modules, radio tuners, and auxiliary audio processors.
- Line Input: Rated at 1V with a 50kΩ input impedance. This dedicated input allows direct connection from commercial audio mixing consoles or permits the SSA-250M to function as a slave booster power amplifier driven by an upstream master mixer.
Loudspeaker Load Matching and Output Taps
The rear-panel terminal strip supports low-impedance voice-coil connections as well as high-voltage distributed line transmission. When configuring speaker networks, the total load must match the specified impedance or power budget:
- Low-Impedance Direct Outputs (4Ω and 8Ω): Designed for direct connection of low-impedance cabinet loudspeakers. Connecting loads below 4Ω must be avoided to prevent triggering the internal protection circuitry.
- Distributed Line Outputs (70V and 100V): Intended for long-distance multi-speaker networks utilizing line-matching transformers. The cumulative tapped wattage of all connected 70V or 100V ceiling speakers, column speakers, or horn speakers must not exceed the amplifier's rated capacity of 250W RMS.
- Acoustic Transducer Selection: Features an integrated Box Speaker / Driver Unit selector switch. When driving compression driver horns, setting this switch to 'Driver Unit' automatically defeats low-frequency bass boost to safeguard driver diaphragms from mechanical damage.
Booster Expansion and Downstream Interconnections
For large-scale industrial plants or expansive outdoor venues requiring greater sound reinforcement than a single 250W unit can provide, the amplifier incorporates dedicated preamplifier and line output ports:
- Preamplifier Output (200mV / 600Ω): Dedicated unbalanced output for routing preamplified master audio to external recording equipment.
- Line Output (1V / 1kΩ): High-level feed designed to daisy-chain up to four Ahuja BR-250M booster power amplifiers, allowing system engineers to scale the installation into a unified 1250W mono public address distribution network.
Electrical Power and DC Backup Interfacing
The SSA-250M operates on standard 220–240V AC 50/60Hz utility power (consuming 460VA to 500VA). For continuous operation during utility outages, the unit includes 24V DC terminals designed for external battery connection (utilizing two 12V external car batteries (they are not included), drawing up to 6A under maximum load) with instantaneous automatic changeover upon AC mains failure.
