Introduction

The P-4600 is Accuphase’s high-power Class AB stereo amplifier, engineered to combine musical finesse with formidable driving capability. Its advanced push-pull output stage delivers 150 W per channel into 8 Ω (300 W into 4 Ω, 450 W into 2 Ω), ensuring effortless control over any speaker, from compact monitors to full-range floor-standers.

Design

At the heart of the P-4600 lies a six-parallel push-pull power-transistor output stage operating in a three-stage Darlington configuration. Combined with Accuphase’s instrumentation-amplifier-principle input circuitry and current-feedback loops, it achieves both high gain (28 dB) and ultra-low output noise. Front-panel gain selectors and large analog meters provide precise control and a clear visual indication of output levels.

Application

Ideal for high-end two-channel systems, the P-4600 also excels in bi-amping or bridged-mode setups—achieving 600 W into 8 Ω and 900 W into 4 Ω when bridged. Its robust speaker-output protection and balanced remote-sensing circuitry make it equally suited for professional installations and demanding home-audio environments.

Technology Overview

• Instrumentation Amplifier Principle
  Ensures exact gain distribution and minimal added noise by keeping the signal path fully differential.
• Current-Feedback Amplification
  Provides fast transient response and stable operation into low-impedance loads.
• MCS+ Circuit (Multiple Circuit Summing)
  Reduces distortion by distributing current among parallel output devices.
• Balanced Remote Sensing
  Compensates for cable losses to maintain constant voltage at the speaker terminals.

Key Features

• Class AB stereo power amplifier with six-parallel push-pull output transistors
• Rated output: 150 W × 2 (8 Ω), 300 W × 2 (4 Ω), 450 W × 2 (2 Ω)
• Bridge-mode capability: 600 W (8 Ω), 900 W (4 Ω)
• High damping factor (800) for tight bass control
• Signal-to-noise ratio: 125 dB
• Total harmonic distortion: 0.03% (20 Hz–20 kHz at rated power)
• Gain selector with four settings: Max, –3 dB, –6 dB, –12 dB
• Speaker-output protection and soft-start circuitry
• Front-panel analog power meters with switchable hold time
• Support for bi-amping and bridged configurations
• Inputs: 1× XLR balanced, 1× RCA unbalanced
• Outputs: Dual five-way binding posts per channel

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