
Pioneer C-Z1 |
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400,000yen(around the 1980 time) |
The unreturned stereo
preamplifier which carries the super linear circuit which solves the
nonlinearity of a transistor aiming at the amplifier of transmit error zero
without using no NFB.
In order to acquire the property which was
excellent without applying NFB, the super linear circuit is carried.
In this
circuitry, it is a scheme which cancels the nonlinearity of a transistor with
the nonlinear transistor in the reverse mode by action of a current mirror.
By considering it as the unreturned amplifier to which NFB is not applied,
the distinctive characteristicses "without the mechanism of a TIM distorted
occurrence" "there is no distortion and a flat property is acquired also for the
frequency characteristic over all the bands since a phase correction is not
needed", like "the stability in a quantity region is good" have been acquired.
Furthermore, the 50 or more piece thing element is being modularized and
used for a super linear circuit. This also acquires the shielding effect over
the improvement in a robustness, reservation of the heat stability of each
element, and external noise, and the improvement in a tone quality is aimed at.
In C-Z1, the super linear circuit is used for two pieces and one flat
amplifier in the equalizer stage per channel, it is total two channels and the
unreturned stream composition is realized using six pieces.
Since a
super linear circuit is fundamentally considered to be a current amplifier, it
has the property to determine a gain by the value of load resistance. In C-Z1,
this distinctive characteristics was used and the current equalizer which gave
the RIAA property to the load intensity is adopted. The maximum permissible
input which was excellent with this scheme is realized.
Compared with
NFB amplifier, the stability of DC voltage in an outputting point becomes
important with unreturned amplifier.
In C-Z1, in order to suppress a
variation of a middle point voltage, the double locked servo regulator who is
stabilized still more nearly doubly and locks the supply voltage of the super
linear circuit stabilized once is employed.
Furthermore, all the coupling
capacitors constituting the cause of coloring of sound are also removed, from an
input to an output is constituted from a whole page hardwired connection, and
the robustness is improved.
In order to prevent the ill effect by the
magnetic substance, the non-magnetic-material structure which uses aluminum
material for all, such as a chassis and a frame, is adopted.
In order to cancel the eddy current generated according to the signal current
and ripple current and to improve a tone quality, the glasscase electrolytic
capacitor is adopted.
To the printed circuit board, an intensity is
high, and glass epoxy excellent in the RF property is adopted.
Furthermore, a Copper foil is considering it as thickness of 140micro, and has reduced direct
current resistance and an inductance.
Reliable
oxygen-free-high-conductivity-copper material is adopted as the product-line
material of a signal system.
The mass double insulation power cord is
adopted as a power cord.
The pin plug code for an interconnection of a
star-quad structure (oxygen-free-high-conductivity-copper line) is equipped
standardly.
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Form |
A unreturned stereo preamplifier
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Input sensitivity/impedance |
Phono: |
2.5mV
Cartridge load capacity: 100, 200
or 400pF
Cartridge load resistance: 25, 50, 100kohm
|
Tuner, Aux, Tape Play:150mV /,
50kohm |
An Output voltage/impedance |
Tape Rec: 150mV / 1kohm
Output: 1V
(rate), 5V (maxima) / 1kohm |
Supply voltage |
AC100V, 50Hz/60Hz |
Power consumption |
60W (Electrical Appliance and Material
Control Law) |
AC outlet |
Power-switch interlock: Three lines, Total
700W
Power-switch un-interlocking.: Two lines, Total 200W |
Dimensions |
Width 220x height 185x depth of 454mm
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Weight |
12.1kg |
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