Accuphase E-307 Stereo Integrated Amplifier (2000)

Name: Accuphase E-307
Brand: Accuphase

A high-end pre-main amplifier refining the E-306V with discrete current feedback topology and independent pre/power sections.

Overview

The Accuphase E-307 Stereo Integrated Amplifier was released in December 2000 by Accuphase Laboratory, Inc. of Yokohama, Japan. It is a pre-main amplifier designed as an evolution of the E-306V, incorporating accumulated design improvements for higher performance. The unit allows independent use of its preamplifier and power amplifier sections via a separate switch and includes both main and preamp input/output terminals. It supports digital input and analog record playback when equipped with an optional board. The amplifier features a moving magnet (MM) and moving coil (MC) phono stage and includes a preamplifier output.

Specifications

Power Output	140W/ch into 4Ω, 120W/ch into 6Ω, 100W/ch into 8Ω (20Hz–20kHz, both channels driven)
Total Harmonic Distortion	0.01% (4Ω–16Ω load)
IM Distortion	0.01%
Frequency Response	20Hz–20kHz ±0.2dB (rated output); 2Hz–150kHz ±3.0dB (1W output)
Damping Factor	100 (8Ω load, 50Hz)
Inputs	Phono MC ×1, Phono MM ×1, Line ×4, Tape ×2
Outputs	Pre Out ×1, Tape Out ×2, Headphone ×1
Input Sensitivity / Impedance	High Level: 113mV/20kΩ; Balanced: 113mV/40kΩ; Main: 1.13V/20kΩ
Output Level / Impedance	Pre out: 1.13V/50Ω
Gain	High Level → Pre out: 20dB; Main → Output: 28dB
S/N Ratio	High Level: 104dB (A-weighted); Balanced: 88dB; Main: 122dB
Tone Control	Bass ±10dB at 300Hz (50Hz); Treble ±10dB at 3kHz (20kHz)
Loudness Compensator	+6dB at 100Hz (Volume -30dB)
Attenuator	-20dB
Power Meter	Logarithmic peak level display with dB scale and 8Ω load reference
Load Impedance	4Ω–16Ω
Headphone Output	4Ω–100Ω
Power Supply	AC 120V/60Hz, 220V/50Hz, or 240V/50Hz
Power Consumption	50W (idle); 240W (compliance); 385W (8Ω rated output)
Dimensions	475mm W × 170mm H × 424mm D
Weight	21.4 kg (47.2 lbs)
Remote Control	Included RC-20 (IR, 2×AA batteries)
Original Price	¥280,000

Design

The E-307 uses current feedback amplifier circuits in both preamp and power amplifier sections, with a fully discrete dual mono construction and DC configuration—no capacitors in the signal path. The line amplifier employs a pure complementary push-pull circuit built from discrete components. The output stage uses parallel push-pull high-power transistors with excellent high-frequency characteristics, mounted on a large heatsink for efficient thermal management. A dedicated power supply isolates the preamp section, and internal layout physically separates preamp and power amp sections. Signal paths are minimized via logic-controlled relays with gold-plated cross-bar twin contacts. The tone control uses an additive active filter design, and dual speaker terminals allow flexible wiring. A 500 VA power transformer and two 22,000 μF filter capacitors provide stable power delivery. The unit includes a high-quality phono equalizer amplifier, a high-precision loudness control, and a subsonic filter.

Context

The E-307 is listed in Accuphase’s Classic Models Reference line and was developed to refine the earlier E-306V by applying accumulated design technology.