|Technics SU-A808||74,800yen/728 USD (1999 release)|
Integrated amplifier which attained low-noise-ization by carrying VGCA.
The original low-noise amplifier VGCA (Variable Gain Control Amplifier) is adopted as an amplifying circuit.
The amplifier stream composition which extracts a signal and is amplified after that in the conventional input volume in this circuitry is stopped, and only a part to be amplified gives gain to amplifier by changing the gain of an amplifier part itself, and it is made to operate as buffer amplifier in the gain not more than it. Moreover, the sound-volume control is performed in the volume which interlocks after amplifier. This has realized the play in the usually used volume location of a clearer sound.
The MOS ClassAA circuitry which adopted based on the ClassAA circuitry and adopted MOS FET as the amplification element is carried.
In the ClassAA circuitry, individual amplifier is performing the voltage amplification and the current supply source, and high power and perfect Class-A voltage control are realized.
In the MOS ClassAA circuitry carried in SU-A808, an input impedance is very high in the last stage which controls the output-terminal of pure Class-A voltage control amplifier, and has adopted the amplification element MOS FET excellent in the linearity as it. Moreover, there are few losses, the bipolar transistor which is acknowledged in the Oide power operation is adopted as the final stage of current-supply-source amplifier, and the correspondence to a digital format of a DVD-Audio etc. is aimed at to it according to the class AA bridge effect of demonstrating the benefit of each amplifier to the maximum extent.
The virtual battery operation circuitry is carried in the power-source fraction. By cutting the wraparound of the noise from other circuitries, capacity [ equivalent to a battery drive power source ] of operation was acquired, and the stable powering is realized.
Moreover, magnetic flux is uniform, R core power transformer with circular core cross-section form is adopted as a power transformer, in order that there may be no joint in a core, there is very little leakage magnetic flux, and the noise occurrence by a magnetic field is suppressed.
The TAKEII electrolytic capacitor is adopted as an electrolytic capacitor.
This capacitor is a new version of the electrolytic capacitor using the separator which blended the bamboo, and has improved mechanical and an electrical specification greatly. Furthermore, the appearance of an aluminum case is equipped with a spiral-shaped coil, and the measures against vibration proof are also taken by fixing by polyolefin sleep. The occurrence of an unnecessary incidental sound is controlled by this.
The gilding RCA termination and the speaker termination corresponding to a banana plug are adopted.
System remote control is attached.
Su-A808 / Su-A707