hifi engine



Accuphase E-307
280,000 yen(December, 2000 release)


The Integrated Amplifier which refined E-306V, concentrated the design technique cultivated until now, and aimed at higher completeness.

The power transistor for multi-emitter type large electric power audios excellent in many characteristics, such as the high frequency characteristic, a current gain linearity, and switching, is adopted as an output element.
This element is constituted from a parallel push pull, low impedance-ization is attained, it fixes on a large-sized heat sink, and efficient heat dissipation processing is carried out.

The current feedback magnification circuit the preamplifier part and the power amplifier part excelled [ circuit ] in the phase characteristic of the high region is adopted.
This circuit lowers the impedance of the input terminal which is a return side, detects current, carries out I-V conversion (current-voltage) of that current with a transformer impedance amplifier, and is making the output signal. Since the impedance of a return input portion is low, it is hard to generate phase rotation, and there is almost no necessity for phase compensation.
For this reason, many characteristics have been sharply improved by a little NFB, and the more natural energy response has been obtained.

The pure complimentary push pull circuit constituted from a discrete part is adopted as a line amplifier part, and this is made it with the current feedback magnification circuit.
Phase compensation of each stage also becomes light by this, and acquisition of natural sound quality is aimed at.

In order to make a straight signal course possible at the shortest, the logic relay control system is adopted.
The sealed type relay for communication industry is adopted as the relay used by this system, and low contact resistance and quantity durability are acquired by making a contact into a plated with gold and a crossbar twin system.

Tone control of an added type active filter system is carried in tone control.
This system passes an original flat signal straight, if needed, is another, and makes the characteristic, and sound quality is adjusted by making it adjust from a flat signal.

Two speaker terminals are carried and proper use and bi-wiring connection are possible by the change of a speaker selector.

The large-sized power transformer of about 500 VA is adopted as a power-source part. Moreover, two 22,000-micro F things are carried in the aluminum electrolytic capacitor for filters.
Furthermore, the exclusive power supply circuit is used for the preamplifier part handling a small signal, and interference with the power amplifier through a power-source part is prevented.

A preamplifier part and a power amplifier part are separated like internal structure and arrangement, and the mutual intervention is suppressed.

In order to monitor output electric power, the logarithm compression type analog type peak power meter is carried.

The separation switch and input-and-output terminal which can use a preamplifier part and a power amplifier part independently are carried.

The balance input is also carried in the input terminal.

The remote commander who can change volume control and an input selector is attached.

Playback of a digital input or an analog record is possible by extension of an option board.

[Guaranteed specifications are measured according to EIA standard RS-490.]

 Continuous Average Output Power (both channels driven, 20 - 20,000 Hz)
140 watts per channel into 4 ohms
120 watts per channel into 6 ohms
100 watts per channel into 8 ohms

 Total Harmonic Distortion (both channels driven, 20 - 20,000 Hz)
0.01%, with 4 to 16 ohms load

 Intermodulation Distortion 0.01%

20 - 20,000 Hz +0, -0.2 dB (for rated continuous average output)
2 - 150,000 Hz +0, -3.0 dB (for 1 watt output)

 Damping Factor 100 (with 8-ohm load, 50 Hz)

 Input Sensitivity, Input Impedance
For rated output For 1 W output (EIA)
HIGH LEVEL INPUT 113 mV 11.2 mV 20 kΩ
BALANCED INPUT 113 mV 11.2 mV 40 kΩ
MAIN INPUT 1.13 V 112 mV 20 kΩ

 Output Voltage, Output Impedance PRE OUTPUT: 1.13 V, 50 ohms
(at rated continuous average output)


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

 Loudness Compensation +6 dB (100 Hz) (Volume control setting -30 dB)
 Attenuator -20 dB
 Signal-to-Noise Ratio
Input shorted, IHF-A weighting
S/N ratio at rated input
MAIN INPUT 122 dB 100 dB

 Power Level Meters Logarithmic compression, peak reading meters dB scale
 Load Impedance 4 - 16 ohms
 Stereo Headphones Suitable impedance: 4 - 100 ohms
 Power Requirements 120 V/230 V (Voltage as indicated on rear panel) AC, 50/60 Hz
 Power Consumption 50 watts idle
240 watts in accordance with IEC-65

 Maximum Dimensions Width 475 mm (18-11/16”)
Height 170 mm (6-11/16”)
Depth 424 mm (16-11/16”)

 Weight 21.6 kg (47.6 lbs) net
26.0 kg (57.3 lbs) in shipping carton