Audio Database Pioneer C-Z1 400,000yen(around the 1980 time) Description �@ 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. 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, 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 Weight 12.1kg