|680,000 yen(December, 1982 release)
The stereo preamplifier which corresponded to the appearance of the digital
audio disc and was developed by the main purpose in an analog and both digital
the base before circuit composition's combining dregs
coding for retrieval with all the magnification stage Class-A push pulls of
Accuphase tradition and giving NFB -- the characteristic is improved.
Since dregs cord connection has little feedback, the good high region characteristic is acquired. Moreover, since a linearity is maintained to the operating limits of an element, distortion decreases and there is a merit of the signal to noise ratio being improved.
Furthermore, a linearity and the distorted characteristic before giving NFB are improved with constituting from a Class-A push pull.
fundamental circuit composition of unit amplifier is common, and has adopted
circuit composition common to head amplifier, equalizer amplifier, and
high-level amplifier. The dregs cord push pull by the dregs cord push pull
differential amplification of the input by eight elements and four elements
consists of three-step magnification fundamentally in two steps of a total of
Furthermore, direct-current servo circuit by IC was carried, and a direct current generated in the output was detected, it returned to the
input, and generating of direct-current drift is prevented. It has become that
there is almost nothing about generating of direct-current drift by this
direct-current servo system and precise design, and all the signal systems of
the output were made direct connection from MC input, and coloring is
A power-source part uses a power transformer for exclusive
use for a right-and-left channel, and serves as a mono-construction which became
independent electrically, structurally, and completely.
Moreover, in order
to measure low impedance-ization over a broadband, a constant-voltage power
source for exclusive use is carried for every unit amplifier, and it has become a total of six multiple power supply systems. Furthermore, the constant-voltage
power-source part of equalizer amplifier constitutes dregs cord differential
amplifier, obtains high gain, and is raising the constant-voltage effect.
Unit amplifier and a constant-voltage power-source part have prevented that
it is stored by thick aluminum housing, wire connection is carried out by the
curtate distance, and power-source impedance becomes high in a high region.
In order to prevent generating degradation of a high region, and an
unstable component by taking about a signal course for functions, such as an
input change and a tape monitor, it is at C-280,The relay was installed in the
place of a required signal course, and the switch controlled these relays
electronically and has changed them in the logic circuit.
In this case, the
encapsulated type relay containing [ which was developed as the object for
audios and an object for communication machines ] nitrogen gas is adopted
especially as the relay used, and contacts are golden tension and a crossbar
twin system of a silver palladium alloy, and have become low contact resistance and a thing of high durability which has high quality.
Furthermore, in order
to improve reliability more, the signal course of a low-level is used by 4
In the equalizer amplifier part, low noise-ization is
further attained by using the element selected carefully.
The silvered mica
condenser developed as an object for audios is adopted especially as a
capacitor. This mica condenser forms a silver thin film in the piece of mica of
high purity selected carefully by the screen method, and also has special
processing and structure of printing a glass pattern (thin glass layer). By
this, corposant starting potential becomes high, it is stabilized also in the
pulse high voltage, and a signal is passed. Furthermore, how to take out the
lead which affects sound quality is considering it as the structure directly
connected to the edge portion of a silver film, and has prevented degradation.
The system which inserts exclusive flat amplifier in front of equalizer
amplifier is used for the head amplifier for MC cartridges.
impedance-ization of a NFB loop is measured at the same time it uses a low noise
element for an input circuit, and resistance noise is decreased sharply.
Moreover, in order to avoid the influence of the noise generated from
direct-current servo, it has returned to the base of the source of low current
instead of the method of returning to - side of differential amplification
directly, and the influence of the noise of a servo system is suppressed.
Since it corresponds to various MC cartridges, MC input impedance can be
changed to a three-stage.
Moreover, the gain changeover switch is also
carried for a low output MC cartridge.
The 600-ohm balance type output
terminal is carried.
The unit amplifier of a total of six right-and-left
channels and a constant-voltage power-source part are stored by thick aluminum
A substrate is fixed with a screw, the output element of Class-A
magnification and the element of the constant-voltage power source are being
stuck and fixed to housing to serve also as heat dissipation, and resonance by
guidance and vibration is prevented.
Two tape recorders are connected
and recording, playback, and a monitor are possible.
Three step type
rotary type Attenuator is carried, and the change of -20dB-30dB and -infinity is
The right-and-left independent type Attenuator type level
level control is carried.
For 0 - -6dB can be correctly adjusted at a 1dB
step to -14dB a 0.5dB step and henceforth.
The Subsonic Filter which
cuts only the subsonic noise of 10Hz or less is carried.
Compensation is carried instead of tone control.
It is possible for the
position of volume to have rectified the frequency response automatically and to
choose two kinds of characteristics with a switch.
jack which performed high-class rhodium plating is adopted, and the outstanding
durability has been acquired with the hardness which is equal also to 100
million slides by 1-micrometer thickness.
The front panel and the persimmon wood case of a gold tone scratch hair
line are adopted.
|Tuner, Line, Tape Play :
||1.0Hz-500kHz+0 -3.0 dB
|THD (new IHF)
||0.005% (with all the input terminals, they
are 20Hz - 20kHz)
power / new IHF output 0.5V)
|Disc(Head amp off) MM: 2.0mV/0.5mV/47kohm
Disc (Head amp+26dB): 0.1mV/0.025 mV/10ohm, 30ohm, 100ohm
amp+32dB): 0.05mV/0.0125 mV/10ohm, 30ohm, 100ohm
Tuner, Line, and Tape
|An Output power/impedance
||Output(unbalanced): 2.0V/1.0 ohm
Output(balanced): 2.0V/600 ohm
Tape rec: 126mV/200 ohms (at the time of
|S/N and input conversion noise
short-circuit IHF-A compensation
|Rated input S/N
||Input conversion noise
|Disc(Head amp off)MM:
|Disc(Head amp +26dB):
|Disc(Head amp +32dB):
|Tuner, Line, Tape Play :
a distortion, 20Hz - 20kHz)
Tape Rec:19.0V (at the time of AD)
|The Disc maximum inlet pressure
0.005% of distortion)
|Disc(Head amp off):300mV
Disc(Head amp +32dB):7.5mV
|Minimum load impedance
||Tuner, Line, Tape Play->output:24dB
Tuner, Line, Tape Play->Tape rec output:0dB
Disc(Head amp off)
Disc(Head amp off) MM->Tape rec output: 36dB
amp is +26dB and +32dB change type.
2: +8dB (100Hz), +6dB
||10Hz, -18 dB/oct
||- 20dB-30dB, -infinity
|The semiconductor used
||Transistor: 225 pieces
FET: 16 pieces
IC: 33 pieces
Diode: 167 pieces
||Width 468x height 171x depth of 396mm