The Rane MA 4 is a four-channel professional audio amplifier designed for installed sound systems requiring compact, high-efficiency power delivery. Operating as a Class D switch-mode design, it delivers 100 watts per channel across four independent outputs in a 1U rack-mount form factor. The unit incorporates a universal voltage, power-factor-corrected switching supply, advanced dynamics processing including soft-knee compression and downward expansion, and selectable high-pass filtering to optimize audio performance across music systems, paging applications, conference reinforcement, and speech systems.
Technical Specifications
• Output Power: 100 watts per channel (4 channels)
• Amplifier Class: Class D Switch-mode
• Power Supply: Universal voltage, power-factor-corrected switching; 85 to 260 VAC, 50 Hz or 60 Hz
• Supply Protection: Under and over-voltage protection; low inrush current; near-perfect power-factor correction
• Voltage Gain: 26 dB
• Input Sensitivity: +22 dBu to +4 dBu; 1.1 Vrms / 3.4 dBu at 1 kHz, 8 ohms; adjustable per channel
• Input Impedance: 10 kΩ per leg (differential, 1 kHz)
• Frequency Response: 20 Hz – 20 kHz
• Total Harmonic Distortion: 0.1%
– Key Features
• Soft-Knee Compressor: 3:1 ratio, 1.5 second attack, 3 dB/second decay, 10 dB soft-knee span; applies to all channels via single ON/OFF switch
• Downward Expander: –70 dBFS threshold, 3:1 ratio, 50 ms attack, 10 dB/second gain reduction; controlled globally
• High-Pass Filters: Selectable 20 Hz, 40 Hz, 60 Hz, or 80 Hz; 12 dB/octave Butterworth alignment; master control for all channels
• Remote Level Control: Linear potentiometers 10 kΩ to 100 kΩ; –80 dB to 0 dB range with 256-step audio taper; daisy-chain capable
• Redundancy Switching: MASTER/SLAVE mode for remote fault reporting and failover operations
• Dynamics Calibration: Self-adjusting compression relative to sensitivity, load impedance, and temperature
– Interfaces & Integration
• Audio I/O: Four-channel input and output via Euroblock connectors
• Remote Control: Euroblock connector with strain relief for external potentiometer integration
• Fault Reporting: Remote fault reporting capability via MASTER/SLAVE configuration
• Front Panel: Power switch only
• Rear Panel: Individual channel gain controls, mode selection, compressor/expander/HPF switching and configuration
