Pioneer M-Z1

Commentary

Non-feedback monaural power amplifier without NFB loop from signal system by super linear circuit.

A super linear circuit is used for the voltage amplifier.
By canceling the non-linearity of the transistor with the non-linearity of the reverse mode, linear amplification is realized without using NFB, and the problem caused by NFB is solved.

An EBT (collective power transistor) with high-speed response is adopted for the output stage.
In order to obtain linearity, the current load per 1 stone is reduced, and 6 units are used in parallel for pure class A amplification, which improves high-frequency reproduction, which tends to be a problem.

In order to achieve DC-stability at the output point, we have adopted double-lock ドサーボ regulators to further improve the reliability of super linear circuits by suppressing fluctuations in mid-point voltage.
In addition, the coupling condenser, which causes coloring of sound, is removed and all stages are directly connected.

Two power transformers are used in the power supply section to reduce the source impedance by equivalent parallel connection, and to further strengthen the power supply drive to the output stage.

In order to eliminate the cause of sound quality degradation, we have adopted a glass case electrolytic capacitor in which the case has been changed from aluminum to glass. The inner surface of the glass case is coated with carbon, and the electrode foil has been improved to improve the sound quality.
In addition, for the small-capacity capacitor, we have adopted a copper foil styrene capacitor using high-purity oxygen-free copper for the electrodes to improve sound quality.

In place of the iron cap for the carbon resistance, a brass cap carbon resistance with brass cap carbon for the drawer part is adopted to suppress the generation of strain.

Non-magnetic aluminum material is used for all parts such as chassis and frame, and in addition, special resin coating is applied to the inside to make the shielding effect uniform.
These non-magnetic structures greatly reduce biotechnological problems and degradation of characteristics caused by magnetic structures.

The printed circuit board is made of glass epoxy, which has high mechanical strength and excellent high-frequency characteristics. In addition, the copper foil has a thickness of 140 μ, about four times that of the conventional copper foil, reducing DC resistance and inductance.
In addition, oxygen-free copper is used for the wiring material of the signal system, and oxygen-free copper is also used for other signal flow areas and connecting fittings.

A protection circuit is used to detect overload, midpoint voltage, and abnormal power supply voltage.
If the midpoint voltage changes abnormally due to an accident such as a short-circuit of the speaker terminal, the speaker and the power amplifier will be disconnected immediately.
It operates as a muting circuit when the power switch is turned on/off.

The power indicator on the entire panel uses a microcomputer 20-point LED display indicator. A logarithmic compression circuit is used to indicate the peak value from 0.001W to 100W maximum without range switching.
It also has a peak hold function and can read peak values.

The power cord uses a double-insulated high-capacity power cord.
In addition, since the polarity is unified from the core wire of the power cord to the internal circuit of C-Z1 and M-Z1, it is possible to match the polarity with the AC line.

The pin plug cord uses a star quad structure made of oxygen-free copper, which reduces cord self-inductance and provides low-loss, high-frequency flat transmission characteristics.

Model Rating

Type	Non-feedback monaural power amplifier
Effective output (20 Hz to 20 kHz)	60W (8 Ω)
Input Sensitivity / Impedance	Input : 1V/50k Ω
Output terminal	Speaker : 8 Ω
Damping factor (20 Hz to 20 kHz, 8 Ω)	80 or more
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	220W (Electrical Appliance and Material Control Law)
AC outlet	Power switch not linked : 1 system, 100W
External dimensions	Width 220x Height 185x Depth 440 mm
Weight	19.1kg