ACCUPHASE P-4600

Hi-End Balanced Stereo Power Amplifier

The Accuphase P-4600 is a high-performance Class AB stereo power amplifier, designed to deliver exceptional driving capability and sound reproduction. Featuring a power section with 6 parallel push-pull power transistors, it offers a rated output of 150W into 8 ohms, easily driving large speakers. With a signal-to-noise ratio of 125 dB and a damping factor exceeding 700, it creates a dynamic and rich listening experience, faithfully reproducing the full spectrum of recordings and the emotional depth of live performances.

Inheriting the P-300 amplifier introduced in 1973, the P-4600 represents the fourth generation of Accuphase's standard Class AB power amplifiers, following the P-4100. Its design has evolved significantly, offering improved performance, ease of use, and an increased maximum output compared to the previous model. The high damping factor ensures flawless operation with any speaker, while the low-noise balanced circuit extracts the finest details from musical sources.

The P-4600 is equipped with large analog "needle" meters, highly sensitive, allowing for output power monitoring even at low volume levels. A gain selector on the front panel offers four settings: Max, -3dB, -6dB, and -12dB, enabling users to adjust gain levels without attenuating signals. This function ensures optimal operation with high-efficiency speakers, reducing residual noise while maintaining stable performance.

The monoblock construction of the amplifier features a custom-made, oversized toroidal transformer and two large 50,000μF capacitors at the center of the unit, ensuring abundant power supply. Each channel is housed in a separate amplification unit to improve isolation and performance. The P-4600 provides a rated output of 150W/8Ω, 300W/4Ω, and 450W/2Ω, vastly surpassing the capabilities of conventional models and offering an incredibly wide dynamic range.

For speaker protection, the P-4600 uses a MOS-FET switch, replacing traditional mechanical relays. This reduces contact resistance, improving both sound quality and reliability. The amplifier also features a new output protection circuit that can detect short circuits at the speaker terminals, along with temperature sensors that monitor the heatsink temperature, ensuring safe operation and preventing damage. When protection circuits are activated, output to the speakers is completely interrupted, and the power meters flash to indicate an abnormal condition, ensuring both safety and optimal performance.

Technical Specifications:

• Power per channel:
• 500W into 1Ω
• 2x 360W into 2Ω
• 2x 180W into 4Ω
• 2x 90W into 8Ω
• Support for Bi-Amping and bridged monaural configuration (1000W into 2Ω, 360W into 8Ω)
• Variable gain: 4 selectable positions (Max, -3 dB, -6 dB, -12 dB)
• Total harmonic distortion (THD): 0.02% from 4 to 16Ω
• Intermodulation distortion: 0.01%
• Signal-to-noise ratio (S/N Ratio): Up to 126 dB
• Input stage: High gain with discrete, low-noise components
• MCS+ Technology: Amplification stage with 4 pairs of bipolar power transistors in parallel Darlington Push-Pull configuration
• Output stage: Current Feedback with Balanced Remote Sensing technology, ultra-low impedance, damping factor exceeding 700
• Power supply: Oversized toroidal transformer with high-capacity filter capacitors, independent power supply for signal input circuit
• Protection: Protection circuit with MOS-FET semiconductor switches certified for high-voltage operation, real-time detection of short circuits and electrical anomalies
• Phase function: Selector to invert pins 2 and 3 of the balanced XLR connection
• Speaker connectors: Dual set of connectors
• Power indicators: Analog power meters
• Dimensions: 465 x 190 x 427 mm
• Weight: 29.2 kg