Accuphase E-650 Class-A Precision Integrated Stereo Amplifier

Features

The E-650 has a  Pure Class A operation (30 watts into 8 ohms). It's  guaranteed linear power: 120 watts into 2 ohms, 60 watts into 4 ohms,30 watts into 8 ohms; and the preamplifier and power amplifier sections can be used separately.

Balanced AAVA volume control

As a first in an integrated amplifier, the E-650 features the sophisticated balanced AAVA type volume control incorporated in Accuphase's top-of-the-line preamplifier model C-3850. Balanced AAVA uses two AAVA circuits driven in a fully balanced configuration. This completely cancels out any external noise and results in unsurpassed S/N ratio.

Output stage with power MOS-FETs in triple parallel push-pull configuration

Triple parallel push-pull output stage with power MOS-FETs and power amplifier stage mounted on a large heat sink. Two identical units are arranged on the left and right sides of the chassis.

Balanced I/O

Instrumentation amplifier principle in power amplifier for fully balanced signal transmission, complemented by MCS+ topology and current feedback amplification circuitry

Strong power supply with massive high-efficiency toroidal transformer and large filtering capacitors.

The E-650 uses a massive power transformer with high output capability. Highly effective filtering is realized with two custom-made aluminum electrolytic capacitors, each with a large 50,000 μF rating.

Specifications

Rated Continuous Average Output Power (both channels operating simultaneously, 20 - 20,000 Hz): 150 W/ch  1-ohm load (music signal only), 120 W/ch  2-ohm load, 60 W/ch  4-ohm load, 30 W/ch  8-ohm load

Total Harmonic Distortion (both channels operating simultaneously, 20 - 20,000 Hz): 0.05% 2-ohm load, 0.03% 4 to 16 ohm load

Intermodulation Distortion: 0.01%

Frequency Response: HIGH LEVEL INPUT, At rated continuous average output: 20  -   20,000 Hz ＋0, –0.5 dB, MAIN IN, At rated continuous average output:  20  -   20,000 Hz ＋0, –0.2 dB, At 1 watt output:3  - 150,000 Hz ＋0, –3.0 dB

Damping Factor: 800 (with 8-ohm load, 50 Hz)

Input sensitivity and impedance (rated output/1W output/Impedance): High Level input -77.7mV/14.2mV/20kΩ, Balanced Input -77.7mV/14.2mV/40kΩ, Main In Line-0.617V/113mV/20Ω, Main In Balanced -0.617V/113mV/40kΩ

Output Voltage and Impedance: PRE OUTPUT 0.617 V, 50 ohms (at rated continuous average output)

Gain: HIGH LEVEL INPUT → PRE OUTPUT :18 dB, MAIN IN → OUTPUT: 28 dB

Tone Controls - Turnover frequency and adjustment range: BASS; 300 Hz   ±10 dB (50 Hz),TREBLE; 3 kHz   ±10 dB (20 kHz)

Loudness compensator: ＋6dB（100 Hz)

Attenuator: ─20 dB

S/N Ratio, Input-converted Noise (SN ratio at rated output/SN ratio EIA): High level Input - 102dB/97dB, Balanced input - 102dB/97dB, Main In - 117dB/101dB

Bar Meter: Represents output voltage value (dB) using 26 points With meter on/off switching function

Output Load Impedance: 2 to 16 ohms

Stereo Headphones Suitable impedance: 8 ohms or higher

Power Requirements: 230v AC, 50Hz

Dimensions (WxHxD, mm): 465 x 191 x 428

Weight: 25.3kg net, 32kg shipped