Parasound A51

Parasound A51

This is a high-performance 5-channel amplifier, meticulously designed for audiophiles and home theater enthusiasts who demand superior sound quality and power. Engineered by the legendary John Curl, this amplifier features advanced circuitry and an array of premium components to deliver unrivaled audio fidelity, dynamic range, and reliability.

Key Features:

• THX Ultra2 Certified: Ensures that the A51 meets the rigorous standards for high-end audio performance in large home theater systems.
• High Bias Class A/AB Operation: The amplifier operates in Class A mode for low-level signals, ensuring optimal sonic purity, and switches to Class AB for higher output, delivering power efficiently and maintaining clarity at all volume levels.
• Balanced and Discrete Inputs: Equipped with balanced XLR inputs and discrete circuits, the A51 offers enhanced signal integrity and reduced noise, ideal for both professional and high-end consumer setups.
• Direct Coupled Design: With no capacitors or inductors in the signal path, the A51 provides an unaltered, transparent audio signal for uncompromising sound quality.
• Premium Power Components: The amplifier boasts a massive 2.2 kVA toroidal power transformer with independent secondary windings for each channel, along with 164,000 μF of power supply filter capacitance, ensuring exceptional current delivery and stability.
• Robust Output Transistors: The A51 is equipped with 40 beta-matched, 15-amp, 60 MHz bipolar output transistors, ensuring high-speed, low-distortion performance even under demanding conditions.
• Comprehensive Protection: Features DC Servo and relay protection circuits, along with AC present, channel status, and high-temperature indicators, ensuring long-term reliability and safety.
• Heavy-Duty Build: Gold-plated RCA input jacks, 24k gold-plated 5-way speaker terminals, and a durable 4u chassis with carry handles and a rack mounting adapter make the A51 as practical as it is powerful.

Specifications:

• Power Output (All Channels Driven):
  250 watts RMS per channel at 8Ω, 400 watts RMS per channel at 4Ω, continuous from 20 Hz to 20 kHz.
• Current Capacity:
  60 amperes peak per channel for powerful dynamic performance.
• Power Bandwidth:
  Extends from 5 Hz to 100 kHz, with a flat response of +0/-3 dB at 1 watt.
• Total Harmonic Distortion (THD):
  Less than 0.2% at full power for clean, distortion-free sound.
• Intermodulation Distortion (IM):
  Less than 0.04% at 16 V RMS balanced, maintaining signal purity.
• Slew Rate:
  Over 130 V/µsecond for fast, accurate signal reproduction.
• Dynamic Headroom:
  Greater than 1.5 dB for handling musical peaks effortlessly.
• Interchannel Crosstalk:
  More than 78 dB at 1 kHz and 63 dB at 20 kHz for excellent channel separation.
• Input Sensitivity:
  1 V input required for 28.28 V output at THX reference levels.
• Input Impedance:
  47 kΩ for unbalanced and 94 kΩ for balanced inputs, ensuring compatibility.
• Signal-to-Noise Ratio (S/N):
  112 dB (IHF A-weighted) for a quiet, noise-free operation.
• Damping Factor:
  Greater than 1100 at 20 Hz for tight control over bass performance.
• Power Requirements:
  110V to 120V standard power supply.
• Dimensions:
  17-1/2" W x 7-5/8" H x 20" D (7" H without feet), designed for versatile placement.