Ahuja SSB-120DP System Compatibility & Audio Interfacing Guide

The Ahuja SSB-120DP medium-wattage public address mixer amplifier is engineered for seamless electrical, acoustic, and system-level interoperability within industrial, commercial, institutional, and assembly environments. Designing a public address infrastructure around the SSB-120DP requires matching speaker line impedances, input source levels, power distribution feeds, and downstream signal processors to its rated electrical specifications.

Loudspeaker Load Matching & Distributed Line Compatibility

The amplifier output stage supports both direct low-impedance acoustic circuits and high-impedance distributed constant-voltage lines:

• Low-Impedance Taps (4Ω, 8Ω, 16Ω): Ideal for direct connection to standard low-impedance PA loudspeakers, driver units, or cabinet speakers. Connected speaker networks must be calculated in series, parallel, or series-parallel topologies to strictly match 4Ω, 8Ω, or 16Ω impedance loads without dipping below minimum rated values.
• Constant-Voltage Line Outputs (70V and 100V): Intended for multi-speaker distributed audio networks in commercial facilities, workshops, and large buildings. Connected speakers must incorporate 70V or 100V line-matching transformers wired strictly in parallel. The aggregate power tap wattage of all connected speakers must not exceed the amplifier's rated continuous capacity of 120W RMS (with a maximum peak output headroom of 160W RMS).
• Load Regulation: Output regulation is maintained at ≤ 2 dB from no-load to full-load conditions at 1 kHz, ensuring stable voltage delivery across distributed speaker circuits.

Audio Input Channel Interfacing

The integrated mixer section provides 7 discrete wired input channels designed to interface with standard analog sound equipment:

• Microphone Inputs (5 Channels): Rated at 0.65 mV input sensitivity with a 4.7 kΩ input impedance, accommodating standard dynamic public address microphones via wired 6.3mm phone jack connections.
• Auxiliary Inputs (2 Channels): Rated at 100 mV input sensitivity with a 470 kΩ input impedance, compatible with standard line-level audio playback equipment, including external CD/media players, preamplifiers, tone generators, and audiovisual signal feeds.

System Expansion: Booster Amplifiers & Recording Gear

For scalable PA architectures requiring elevated output wattage or localized monitoring and archival feeds, the unit provides dedicated pre-power line interfacing:

• Line Output (1V / 1kΩ): Compatible with external slave power amplifiers and booster units, enabling line-level audio distribution to expand sound coverage across large industrial complexes without signal degradation.
• Preamplifier Output (200mV / 600Ω): Provides an unamplified pre-master audio feed compatible with external recording equipment, secondary zone mixers, and audio monitoring units.

Digital Media & Storage Card Interfacing

The integrated digital audio player reads standard MP3 audio files directly from external solid-state storage media:

• USB Port: Compatible with standard FAT-formatted USB flash drives for direct MP3 playback.
• SD/MMC Slot: Compatible with standard SD and MMC memory cards.
• Infrared Remote Control: Allows wireless transport control of the digital player section; the handheld remote requires cells (they are not included).

Power Infrastructure & 12V DC Battery Backup Interoperability

The SSB-120DP features dual-mode power sourcing for uninterrupted industrial and emergency operation:

• AC Mains Operation: Operates on standard 220–240V AC (50/60 Hz) utility lines with a nominal power consumption of 250VA.
• DC Standby & Failover: Compatible with 12V DC external power sources, including 12V automotive batteries (they are not included) and industrial 12V battery banks (they are not included), drawing up to 5.5A under full load. The unit incorporates automatic changeover circuitry that instantly transfers operation from AC mains to DC battery power upon utility power failure.

Interfacing Parameters Summary