Chassis Placement and Mechanical Mounting
The Ahuja TZA-7000 is an industrial-grade dual-zone public address power amplifier measuring 510 mm (W) × 185 mm (H) × 470 mm (D) with a net chassis weight of 39.8 kg. Due to the high-density power transformer and dual-channel amplifier stage, ensure the unit is mounted on a structurally reinforced tabletop, equipment shelf, or standard audio rack with adequate mechanical support capable of carrying the amplifier's weight. Maintain clear airflow clearance around the chassis intake and exhaust vents to avoid thermal build-up during sustained high-output operation.
Primary AC Mains and 36V DC Battery Wiring
The TZA-7000 operates on dual power sources supporting primary AC mains and emergency DC battery operation:
- AC Mains Connection: Connect the amplifier to a stable 220–240V AC, 50/60 Hz single-phase mains supply. The system draws up to 1100 VA under maximum operating loads.
- DC Backup Power Connection: For uninterrupted public address operation during mains outages, connect a 36V DC battery bank composed of three 12V car battery (they are not included) units wired in series to the heavy-duty DC terminal strip. The amplifier draws up to 13A on DC operation.
- Automatic Power Transfer: The internal power circuitry automatically and instantaneously switches over to 36V DC battery backup (they are not included) power upon AC line failure without signal dropping or manual switching.
Speaker Load Connections and Zone Impedance Matching
The amplifier delivers a total power output of 700 Watts (500W + 500W Max; 350W + 350W RMS at 10% THD, 300W + 300W RMS at 5% THD, and 280W + 280W RMS at 2% THD). Each zone features independent terminal taps offering flexible loudspeaker load matching:
- Low-Impedance Systems: Connect direct low-impedance loudspeaker loads to either the 4 Ω or 8 Ω terminal taps for local high-fidelity sound reinforcement.
- High-Impedance Distributed Lines: Wire long-distance distributed ceiling speakers, column speakers, or horn arrays using the 70V or 100V constant-voltage line output taps. Ensure the aggregate wattage of all line-matching transformers per zone does not exceed the zone rated RMS output. Output voltage regulation across both zones is ≤ 2 dB from no load to full load at 1 kHz.
- Box Speaker / Driver Unit Selector Switch: Configure the rear selector switch for each zone depending on transducer type. Setting the switch to 'Driver Unit' automatically defeats the bass boost circuit, protecting acoustic driver diaphragms from destructive low-frequency over-excursion.
Input Interfacing and Audio Line Routing
Connect microphones, background audio sources, and external mixing consoles into the designated input channels:
- Microphone Inputs: Connect dynamic microphones to the 6 × Mono Mic inputs rated at 0.6 mV sensitivity into 4.7 kΩ input impedance.
- Auxiliary & Line Inputs: Terminate external media sources to the 2 × Mono Aux inputs (100 mV / 470 kΩ), Stereo L/R inputs (200 mV / 100 kΩ), or Line L/R inputs (1V / 50 kΩ).
- Mixer & Booster Link: Utilize the dedicated Line Input and Line Output (1V / 1 kΩ) terminals on each zone to slave external booster amplifiers or accept feeds from master mixing consoles.
- Preamp Output: Connect the dedicated Preamplifier output (200 mV / 600 Ω) to external audio recording devices for logging or archiving.
Tone Adjustment, System Monitoring, and Protection
Calibrate system audio response across the 50 Hz to 15,000 Hz (±3 dB) operating frequency spectrum using the independent front-panel Bass (±10 dB at 100 Hz) and Treble (±10 dB at 10 kHz) controls with an overall signal-to-noise ratio of 60 dB. Real-time audio levels can be monitored via the integrated LED bar graph signal display. In the event of an electrical short-circuit or continuous load overload across speaker lines, the integrated resettable circuit breaker trips instantly to protect internal amplifier output stages and can be manually reset once the external wiring fault is cleared.
