Audio Database


Accuphase E-303X
298,000yen (December, 1983 release)

Integrated stereo amplifier of the new generation who considered playback of digital sauce, such as PCM and CD, based on the development technology and the material which were cultivated with high-class separation amplifier.

The output stage has adopted the triple push pull composition by six MOS FET, and PD (the drain maximum loss electric power) is giving a sufficient margin called 600W.
In the whole power amplifier part, it has the composition that MOS FET drives by the predrive according [ the next ] to a dregs cord push pull and two transistors according [ a prestage ], to a differential push pull.
It is a circuit system used in the high frequency magnification circuit of a tuner, and a Miller effect does not occur in high frequency, but the dregs cord is excellent in the high region characteristic.

MC head amplifier, equalizer amplifier, high-level amplifier, and all power amplifier have realized the form of a direct connection system. High reproduction which does not have coloring by this is aimed at.
The problem of direct-current drift generated by direct connection stabilized each unit amplifier by direct-current servo, and is solved.

In the input, it is the composition which calls a dregs cord the differential and the predrive in which equalizer amplifier passed the FET buffer, and a final stage calls Darlington, and the whole of each stage consists of push pulls.
Low distorted-ization is expectable over a broadband with the dregs cord connection excellent in the high region characteristic of a predrive.
A power source prepares a constant-voltage power-source part in the same board, and is attaining strengthening.

The full-scale composition which installs exclusive flat amplifier in front of EQ amplifier is used for the head amplifier for MC cartridges.
The signal with detailed MC cartridge does not let a capacitor pass, but direct input is carried out, it selected the low noise element carefully, measured low impedance-ization of the NFB loop simultaneously, and has prevented generating of noise.
Moreover, in order to prevent the noise of the constant voltage circuit of a power source having a bad influence on a signal, the low noise design which selected the element of the constant-voltage power-source part carefully, and was put into practice has been performed.
The input impedance of MC cartridge can be changed to a three-stage (10ohm, 30ohm, and 100ohm).

The signal from an input terminal was directly linked with the print circuit board, the relay has been arranged in the near position, and the signal course is combined at the shortest by controlling this relay by a logic circuit.
Especially the relay has adopted the high reliability relay of a crossbar twin system in which the golden layer was made to form as the silver palladium alloy developed as an object for small signal audios. Furthermore, by sealing, it intercepts with the open air and durability is raised.

It is a switch type from which an exact curve is obtained, and tone control is change of a 1.5dB step, and detailed control is possible for it.

The loudness Compensation which rectifies the energy balance at the time of small volume is carried.
Three kinds of characteristics can be chosen according to the acoustic feature of the room, a speaker, and liking.

The power output meter can carry out the Direct reading of the output in logarithm compression type peak support.

The tape monitor switch which can monitor the sound which can connect two sets of recorders, and records, or is recorded, and the switch which can be dubbed between two tape recorders regardless of the program sauce chosen with the input selector are carried.

The function of a Subsonic Filter, the Attenuator which lowers volume with volume control fixed, 2 sets of speaker changeover switches, a mode switch, etc., etc. is carried.

The cabinet of the natural rosewood was an option.

Rear Head

Rating of a mode
Form Integrated stereo Integrated Amplifier
Continuation average output
(EIA, both channel operation)
20Hz - 20kHz, 0.01% or less of a distortion
4ohm load: 200 W/ch
8ohm load: 150 W/ch
16ohm load: 75 W/ch
THD (EIA, both channel operation) 0.01% (with load of 4ohms or more, they are 20Hz - 20kHz, 0.25W - an Output power)
IM distortion (EIA) 0.005%
Frequency response (EIA)
Main Amp Input: 20Hz-20000Hz+0 -0.2dB (at the time of an Output power)
1.5Hz-150000Hz+0 -3.0dB (at the time of 1W output)
High Level Input: 20Hz-20000Hz+0 -0.2dB (at the time of an Output power)
Low Level Input: 20Hz-20000Hz+0.2 -0.2dB (at the time of an Output power)
Dumping factor (EIA) 150 (8-ohm load, 50Hz)
Input sensitivity/impedance
(An Output power / EIA1W output)
Disc MM(Head amp off): 2.7mV/0.22mV/47kohm
Disc MC(Head amp on): 0.085mV/0.007mV/10, 30, 100ohm
Tuner, Line, and Tape play:170mV/13.9mV/20kohm
Main amp input: 1.4V/0.12mV/20kohm
The disc maximum input (1kHz, 0.005% of distortion) Head Amp Off:300mVrms
Head Amp On:9.5mVrms
An Output power/Output load impedance Pre Output: 1.4V/200 ohm
Tape Rec Output: 170mV/200 ohms (in the case of DISC)
Headphones: 0.4V, conformity impedance 4-100ohm
Gain Main Input -> Output: 27.8dB
High Level Input -> Pre Output: 18.4dB
DISC Input(Head Amp Off) -> Tape Rec Output: 36dB
DISC Input(Head Amp On) -> Tape Rec Output: 66dB
S/N, input conversion noise
Input short-circuit and A-compensation EIA
At the time of a rated input Input conversion noise
Main Amp Input: 123dB -120dBV 102dB
High Level Input: 105dB -120dBV 82dB
DISC(Head Amp Off): 86dB -137dBV 80dB
DISC(Head Amp On): 72dB -153dBV 80dB
Tone control 10 step control
Turnover point Low-pitched sound: 200Hz, 500Hz
Loud sound: 2kHz, 7kHz
Low-pitched sound 500Hz : ±7.5dB (100Hz), a 1.5dB step
200Hz : ±7.5dB (50Hz), a 1.5dB step
Loud sound 2kHz : ±7.5dB (10kHz), a 1.5dB step
7kHz : ±7.5dB (50kHz), a 1.5dB step
Loudness Compensation
(Volume -30dB)
Comp 1:+3dB(100Hz)
Comp 2:+6dB(100Hz)
Comp of 3:+8dB (100Hz), +6dB (20kHz)
Subsonic Filter 17Hz, -12 dB/oct
Attenuator -20dB
Power meter Logarithm compression type peak level display
dB and the output Direct reading at the time of 8-ohm load
Load impedance 2-16ohm
The semiconductor used Transistor: 108 pieces
FET: 23 pieces
IC: 17 pieces
Diode: 103 pieces
Power source AC100V/117V/220V/240V, 50Hz/60Hz
Power consumption At the time of no inputting: 90W
Electrical Appliance and Material Control Law: 320W
At the time of an 8ohm load Output power: 550W
Dimensions the width 445x height 160(piece -- it includeds) x depth of 370mm
Weight 20.5kg
Option: Wood cabinet A-8 (\16,000)
Dimensions Width 466x height 190x depth of 385mm