Pioneer C-Z1a
¥ 460,000 (released in 1983)
Commentary
A non-feedback preamplifier with improved bare characteristics to achieve 0 transmission error.
The circuit is refined based on the super linear circuit which was developed in C-Z1 and solved the non-linearity of the transistor.
Returning to the starting point of the amplifier design of "faithfully amplifying the input signal and extracting it as an output signal", we developed and adopted a super linear circuit that cancels the non-linearity of the transistor with the non-linearity transistor of the reverse mode in order to obtain excellent characteristics without applying NFB.
As a result, it becomes a non-feedback amplifier, and the mechanism of high-frequency instability and TIM distortion caused by the time delay in returning the output signal to the input stage due to NFB is suppressed.
The C-Z1a uses two superlinear circuits per channel for the equalizer stage and one for the flat amplifier. In total, six superlinear circuits are used for two channels, and the configuration is non-feedback with no NFB loop in the signal system from the inlet to the outlet.
Since the super linear circuit is considered as a current amplifier, the gain is determined by the value of the load resistance. Taking advantage of this characteristic, a current equalizer with RIAA characteristics is used for the load.
By connecting an equalizer element consisting of a capacitor and a resistor to form an equalizer amplifier with RIAA characteristics, we have achieved a maximum allowable input that is unattainable with conventional CR types.
Stability of the DC voltage at the output point is important for a non-feedback amplifier.
The C-Z1a uses double-lock ドサーボ regulators that stabilize and lock the supply voltage of the super linear circuit, which has been stabilized once, to double in order to suppress the fluctuation of the midpoint voltage. All stages from input to output are directly connected to improve reliability.
In order to prevent adverse effects caused by magnetic materials, the chassis and frame are all made of non-magnetic materials using aluminum materials.
It uses a glass-case power capacitor that eliminates wake current caused by signal current and ripple current and realizes good sound quality.
A non-magnetic brass cap carbon resistor is used for the lead wire lead part.
The printed circuit board uses glass epoxy, which has high strength and excellent high-frequency characteristics.
In addition, 280 μ oxygen-free copper foils are used for the EQ board to reduce DC resistance and inductance.
We have adopted a newly developed original film condenser for equalizer elements with a composite structure of polystyrene and polypropylene.
Highly reliable oxygen-free copper materials are used for signal wiring.
Star quad structure connection pin plug cord (oxygen-free copper wire) is equipped as standard.
Uses a large capacity double insulated power cord.
.JPG)
.JPG)
Model Rating
| Type | Nonfeedback stereo preamplifier | ||
| Input Sensitivity / Impedance |
AUX : 150mV/50k Ω Tape Play : 150mV/50k Ω |
||
| Output Level / Impedance | Tape Rec : 150mV/1k Ω Output : rated 1 v, max. 5V/1k Ω |
||
| Power supply voltage | 100 VAC, 50Hz/60Hz | ||
| Power consumption | 60W (Electrical Appliance and Material Control Law) | ||
| AC outlet | Power switch interlock : Route 3, total 700W Power switch not linked : 2 systems, total 200W |
||
| External dimensions | Width 220x Height 185x Depth 454 mm | ||
| Weight | 12.1kg |