|330,000 yen(June, 1984 release)
Stereo control amplifier which inherited the circuit technology of the high-end
model C-280 based on C-200X, and was developed.
The circuit composition of an equalizer and high-level amplifier has adopted
the dregs Class [ A ] cord push pull system which prepared the FET buffer
for direct connection for the input, the following stage is a dregs Class
[ A ] cord push pull, and the output serves as the A Class-A Darlington
Dregs cord connection has
little feedback during input and output, and has the feature that the good
characteristic is acquired especially in a high region. Moreover, a profit is
large, a linearity is maintained to the operating limits of an element,
distortion decreases, S/N is also improved, and the outstanding characteristic
can be acquired.
Furthermore, since the Class-A Darlington push pull is adopted as an output
and input impedance can be made high, operation of the preceding paragraph
cannot be easily influenced by load, and can constitute the amplifier of
a low distortion and an extensive dynamic range.
amplifier for MC cartridges has adopted the full-scale method of inserting
exclusive amplifier in front of equalizer amplifier, and circuit composition has
three-step composition of a dregs cord differential push pull + dregs cord push
pull + Darlington push pull.
Since head amplifier has the extremely low
signal level, it is selecting a low noise element carefully and also performing
the low impedance design of a circuit, and is aiming at the improvement of S/N.
direct-current servo circuit by IC is carried in each unit amplifier.
This is a circuit which detects the direct-current ingredient generated in an
output, feeds back to an input by negative phase, and prevents generating of a
direct current, can constitute all the unit amplifier from direct connection by
this, and is suppressing coloring.
While driving each unit amplifier by
independent winding wire and an independent rectifier circuit, building an
exclusive constant-voltage power source in unit amplifier, respectively and
attaining stabilization, interference between unit amplifier is intercepted.
Since a straight signal course is constituted at the shortest, a relay
is installed in the place of a required signal course, and it is changing by a
switch controlling these relays electronically in a logic circuit.
only for an audio of an encapsulated type is used for a relay, and durability is
raised reliability and over a long period of time.
Since it corresponds
to various MC cartridges, three steps of MC input impedance can be changed.
Moreover, the gain changeover switch is provided so that high gain of 36dB can
be obtained to everything but a usual head amplifier profit of 26dB for a low
output MC cartridge.
The 600-ohm balance type output is carried.
The step system by a right-and-left independent type 11 contact rotary
switch is adopted as tone control, and the turnover changeover switch is
provided in it so that change of only heavy low-pitched sound and the highest
compass can also be performed.
The on-off switch of which tone control is
canceled is carried.
Hearing impression at the time of small volume
reproduction was rectified, and the loudness Compensation switch which prepares
energy balance is formed.
It is possible to choose two kinds of curves
according to the characteristic of a regeneration level or a listening room, and
the degree of compensation is automatically adjusted with the position of volume
Three tape recorders can be connected and mutual dubbing
is also possible.
There was a wood cabinet of native wood rosewood finishing as an option.
|Tuner, Line, Tape play :
||1.0Hz-500kHz+0 -3.0 dB
|THD (EIA, 20Hz - 20kHz)
||0.005% (with all the input terminals)
power / EIA 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 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:19V (at the time of Disc)
|The Disc maximum inlet pressure
0.005% of distortion)
|Head amp off:300mV
Head amp +26dB:15mV
Head amp +32dB:7.5mV
|Minimum load impedance
||Tuner, Line, Tape play->Output:24dB
Tuner, Line, Tape play->Tape rec:0dB
Disc(Head amp off, MM)
Disc(Head amp off, MM) ->Tape rec: 36dB
Head amp is
+26dB and +32dB change type.
||10 step control
||500Hz : }7.5dB (100Hz), a 1.5dB step
200Hz : }7.5dB (40Hz), a 1.5dB step
||2kHz : }7.5dB (10kHz), a 1.5dB step
: }7.5dB (35kHz), a 1.5dB step
Comp of 2:+8dB
(100Hz), +6dB (20kHz)
||10Hz, -18 dB/oct
|The semiconductor used
||Transistor: 164 pieces
FET: 16 pieces
IC: 21 pieces
Diode: 123 pieces
|Power supply voltage
||the width 445x height 160(piece -- it
includeds) x depth of 373mm
Width 466x height 190x depth of 385mm (at the
time of wood cabinet wearing)
||Wood cabinet A-8 (16,000yen)