Audio Database


Accuphase E-305
270,000 yen(December, 1987 release)

The Integrated Amplifier developed towards an audio new time taking advantage of the development technology and the material of separation amplifier which have been cultivated for years.

Three full-scale amplifier composition of the equalizer amplifier for an analog disc, a high gain preamplifier, and power amplifier is adopted, and each completeness is raised.

The output stage of a power amplifier part is 3 parallel push pull with six transistors, and Pc (collector loss) constitutes per [ 130W ] element and an output stage as powerful as a total of 780W.
The "low load drive" which can send in sufficient power also to a low load impedance by this is realized.
MOS FET is adopted as the preceding paragraph which drives an output stage.
Moreover, an input stage is dregs coding for retrieval, and has realized the broadband and the high linearity conjointly with constant current load.
And the differential amplification circuit of the following stage constituted the complimentary circuit with 1 chip dual transistor, and has acquired the stability excellent in the low noise.

All the unit amplifier of each stage has composition of a direct connection system from the analog disc input.
Moreover, the problem of direct-current drift generated by direct connection stabilized each unit amplifier by direct-current servo, and is solved.

In order to suppress interference between the unit amplifier by a power-source part, or electrostatic and electromagnetic induction, the transformer winding wire of a preamplifier part and a power amplifier part is made to become independent for interference of the circumference of a power-source part, and the exclusive power source is constituted in it.
Furthermore, the preamplifier part was stabilized by the full-scale constant voltage circuit, and has improved to independent case amplifier and an equivalent level.
Moreover, careful arrangement and cover are performed to electrostatic and electromagnetic induction.

The system changed according to the respectively required gain of MC type and MM type is used for an equalizer amplifier part.
And the stable circuit which constituted a low noise and high gm FET from a differential circuit with 3 parallel dregs cord bootstrap to the input, and excelled [ direct connection / input ] in S/N is realized. receiving MC cartridge of a small incoming signal especially -- 3 -- the remains noise is reduced more parallel.

In order that the input unit may prevent that signal degradation gets angry by leading about of a change and a signal course, it installed the relay in the required place of a change, and the system which controls them electronically by a logic circuit is used for it.
The encapsulated type of a crossbar twin silver palladium money tension contact is adopted as this relay.

In addition to eight lines, the input terminal carries two balance terminals.
Moreover, since the recording selector is carried and it is made to become independent of an input selector, it can perform recording an FM broadcast etc., hearing CD.
Moreover, dubbing between recorders and the copy switch made independently are carried.

A preamplifier and power amplifier are separated electrically and the separate input-and-output terminal which can be used as independent amplifier is carried.

The added type active filter system currently used also for the graphic equalizer is developed and carried in tone control.
It passes straight, an original flat signal makes another characteristic if needed, and this system is a system adjusted from a flat signal.

The logarithm compression peak directions type peak power meter is carried.

Yesterday, such as a mode switch which mixes the speaker selector which changes 2 sets of speakers, and a sound on either side, a Subsonic Filter which cuts the harmful super-low-pass noise of an analog disc, and a Compensation which reinforces the feeling of low-pitched sound at the time of small volume, is carried.

As for the front panel, the sideboard by the persimmon of a natural tree is attached to both sides by the gold tone scratch hair line design.


Rating of a mode
Form Integrated stereo Integrated Amplifier
Continuation average output (both channel operation)
20Hz - 20kHz, 0.02% of a distortion
4ohm load: 180 W/ch
8ohm load: 130 W/ch
THD (both channel operation)
0.25W - a continuation output, 20Hz - 20kHz
0.02% (4-16-ohm load)
IM distortion 0.01%
Frequency response
Main Amp Input: 20Hz-20000Hz+0 -0.2dB (at the time of an Output power)
0.5Hz-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 -0.5dB (at the time of an Output power)
Dumping factor 100 (8-ohm load, 50Hz)
A rated input / input impedance
Input sensitivity Impedance
At the time of an Output power EIA (at the time of 1W output)
AD Input(MC): 0.128mV 0.01mV 100ohms
AD Input(MM): 4.3mV 0.38mV 47kohm
High Level Input: 125mV 11.8mV 20kohm
Balanced Input: 125mV 11.8mV 40kohm
Main Amp Input: 1.28V 121mV 20kohm
The disc maximum input
(1kHz, 0.005% of distortion)
MM input: 300mVrms (Rec Out)
MC input: 8.0mVrms (Rec Out)
An Output power/Output load impedance Pre Output: 1.28V/200 ohm
Tape Rec Output: 125mV/200 ohms (AD)
Headphones: 0.4V, conformity impedance 4-100ohm
Gain Main Input -> Output: 28dB
High Level Input -> Pre Output: 20dB
AD Input (MM) -> Tape Rec Output: 29dB
AD Input (MC) -> Tape Rec Output: 60dB
S/N, input conversion noise
Input short-circuit and A-compensation EIA S/N
At the time of a rated input S/N Input conversion noise
Main Amp Input: 123dB -121dBV 102dB
High Level Input: 108dB -126dBV 82dB
Balanced Input: 90dB -108dBV 82dB
AD Input(MM): 86dB -137dBV 80dB
AD Input(MC): 66dB -147dBV 75dB
Tone control Low-pitched sound: Turnover frequency 300Hz, ±10dB (50Hz)
Loud sound: Turnover frequency 3kHz, ±10dB (20kHz)
Loudness Compensation + 6dB (100Hz, Volume-30dB)
Subsonic Filter 17Hz, -12 dB/oct
Attenuator -20dB
Power meter Logarithm compression type peak level display
dB scale and the output Direct reading at the time of 8-ohm load
Load impedance 2-16ohm
The semiconductor used Transistor: 77 pieces
FET: 34 pieces
IC: 20 pieces
Diode: 78 pieces
Power source 100V/117V/220V/240V, 50Hz/60Hz
Power consumption At the time of no inputting: 60W
Electrical Appliance and Material Control Law: 310W
At the time of an 8ohm load Output power: 490W
Dimensions the width 475x height 170(piece -- it includeds) x depth of 375mm
Weight 20.5kg