Audio Database


Pioneer C-Z1a
460,000yen(1983 release)

The unreturned preamplifier which raised the nakedness property of amplifier in order to realize transmit error zero.
It develops by C-Z1 and the circuitry is polished up based on the super linear circuit which solved the nonlinearity of the transistor.

It returned to the origin of the amplifier design of "amplifying an input signal faithfully and taking out as an output signal", and in order to acquire the property which was excellent without applying NFB, the super linear circuit which cancels the nonlinearity of a transistor with the nonlinear transistor in the reverse mode is developed and adopted.
This becomes unreturned amplifier and the time delay which returns an output signal to an input stage by NFB is suppressing the instability of a high region and the occurrence mechanism of TIM distortion which are generated owing to.
In C-Z 1a, this super linear circuit is used for two pieces and one flat amplifier in the equalizer stage per channel, if total two channels, six pieces are used, and it has unreturned composition which does not have a NFB loop in a signal system from an entry point to an outlet.

Since a super linear circuit is considered to be a current amplifier, it has the property to determine a gain by the value of load resistance. This special feature was used and the current equalizer which gave the RIAA property to the load intensity is adopted.
The equalizer element which consists of a capacitor and a resistor was connected, and forming an equalizer amplifier with a RIAA property has realized the maximum permissible input to the extent that it does not think in the conventional CR type.

With unreturned amplifier, the stability of DC voltage in an outputting point becomes important.
In C-Z 1a, in order to suppress a variation of a middle point voltage, the double locked servo regulator who stabilizes still more nearly doubly the supply voltage of the super linear circuit stabilized once, and locks it is employed, 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, it has a non-magnetic-material structure which adopted aluminum material as all, such as a chassis and a frame.

The eddy current generated according to the signal current and ripple current was canceled, and the glasscase power-source capacitor which realizes the good tone quality of an omission is adopted.

Non-magnetic material and a brass cap carbon resistor are used for a lead-wire drawer part.

To the printed circuit board, an intensity is high, and glass epoxy excellent in the RF property is adopted.
Furthermore, 280micro oxygen-free-high-conductivity-copper foil was used for the equalizer substrate, and direct current resistance and an inductance are reduced.

The film capacitor for newly developed original equalizer elements by the compound structure of a polystyrene and polypropylene is adopted.

Reliable oxygen-free-high-conductivity-copper material is used for the product-line material of a signal system.

The pin plug code for an interconnection of a star-quad structure (oxygen-free-high-conductivity-copper line) is equipped standardly.

The mass double insulation power cord is adopted.

Rear Super

Rating of a mode
Form A unreturned stereo preamplifier
Input sensitivity/impedance
Phono: 2.5mV
Cartridge load capacity: 100, 200 or 400pF
Cartridge load resistance: 25, 50, 100kohm
Tuner: 150mV / 50kohm
AUX: 150mV / 50kohm
Tape Play: 150mV / 50kohm
An Output voltage/impedance Tape Rec: 150mV / 1kohm
Output: Rate 1V, maxima 5V/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
Weight 12.1kg