|
| 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.
|
| 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 |
|
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