ขาย Power Amp NAKAMICHI 620 สวย เสียงดี หายาก ทำงานสมบูรณ์ Made in Japan
ขาย Power Amp NAKAMICHI 620 สวย เสียงดี หายาก ทำงานสมบูรณ์ Made in Japan
เสปค และ รีวิวร์จากต่างประเทศครับ...
Nakamichi 620
Stereo Power Amplifier (1977-79)
Description
Nakamichi's Complete Mirror design brings a level of performance to class B amplifiers that
was formerly associated only with class A amplifiers.
The 620 is closer to a pure class B amplifier than anything else that has gone before. The
first stage of the 620 is a differential amplifier with "current mirror" loading. The final section of
the amplifier is a four stage push-pull circuit.
All four stages are full complementary direct coupled, and each stage employs a unique
double NPN/PNP combination for the positive and negative halves. This design eliminates
the errors inherent in even the most carefully matched pairs of NPN/PNP output devices.
These errors, furthermore, are eliminated without the use of bias diodes, bias adjustments
and high idle currents.
The 620, in fact, idles at approximately 1/20 the current of conventional class B power
amplifiers of comparable output power.
This new approach takes full advantage of class B efficiency with the freedom from switching
and crossover distortions that was once thought possible only with class A amplifiers.
Specifications
Power output: 100 watts per channel into 8Ω (stereo)
Frequency response: 5Hz to 100kHz
Total harmonic distortion: 0.005%
Damping factor: 100
Signal to noise ratio: 120dB
Semiconductors: 3 x ICs, 46 x transistors, 41 x diodes
Dimensions: 400 x 189 x 248mm
Weight: 12.5 kg.