Chassis Mounting and Physical Placement
The Ahuja APA-240 is built in a heavy-duty 19-inch rack-mountable chassis measuring 485 mm in width, 142 mm in height, and 405 mm in depth, with a total unit weight of 20.6 kg. System integrators can install the booster amplifier directly into standard 19-inch equipment racks or deploy it in standalone tabletop configurations across commercial, institutional, and industrial facilities.
When racking multiple power units, ensure adequate vertical spacing within the equipment rack to support ambient air circulation. The substantial 20.6 kg chassis requires secure fastening using appropriate rack screws and rail supports within the cabinet to prevent mechanical stress on the front mounting ears.
Audio Input Connections and Cascade Configuration
The amplifier provides versatile input interfaces to integrate with preamplifiers, audio mixers, or existing high-voltage public address distribution lines:
- Balanced Line Inputs: Two 1V / 50kΩ balanced inputs terminated via standard XLR connectors, providing low-noise transmission across extended cable runs. One 1V line input features priority override over all other input sources, ideal for emergency paging.
- Unbalanced Auxiliary Input: One 200mV / 470kΩ unbalanced input for standard line-level audio equipment.
- 100V Distribution Line Input: A dedicated 100V high-voltage input allows the APA-240 to receive speaker line feeds directly from an upstream master amplifier, enabling booster distribution over long distances.
- Loop-Through Line Outputs: Rear loop-through outputs—rated at 1 × 200mV / 600Ω and 2 × 1V / 1kΩ—facilitate clean signal chaining into additional slave booster amplifiers without signal degradation.
Loudspeaker Load Matching and Tap Selection
The amplifier delivers up to 415W Max. (325W RMS at 10% THD, 300W RMS at 5% THD, and 275W RMS at 2% THD) with an output regulation of ≤ 2 dB from no load to full load at 1kHz. Installers must match speaker cabling to the correct output terminal barrier strip according to system architecture:
| Output Terminal | Impedance / Voltage Rating | Typical Application |
|---|---|---|
| Direct Low-Impedance | 4 Ω / 8 Ω | Short cable runs, high-fidelity local sound systems |
| Constant Voltage Line | 70V / 100V | Long-distance multi-speaker distributed networks (matching transformers) |
Mains AC Wiring and 24V DC Emergency Backup
Connect the amplifier to a stable AC 220–240V 50/60Hz mains supply (power consumption rated at 600VA). For critical communication setups requiring uninterruptible public address operation, connect a 24V DC auxiliary source (operable via 2 × 12V Car Battery (they are not included)) drawing up to 7A. The unit features built-in instant transfer circuitry that switches seamlessly to 24V DC battery power (they are not included) if primary AC power fails.
Ground Loop Hum Mitigation and Circuit Protection
In multi-unit rack installations, ground potential differences can create audible 50Hz mains hum. The APA-240 includes a dedicated ground lift switch on the rear panel that isolates signal ground from chassis earth to break ground loops instantly. The amplifier is equipped with an integrated resettable circuit breaker that guards against excessive thermal overloads and external loudspeaker line short circuits.
