|130,000yen(around the 1978 time)
It is the stereo power amplifier which realized direct-current-ization.
The phase distortion of a low-pitched sound
region was thought as important, and direct-current system which excluded
entirely the condenser used as the damping time constant of a magnification
circuit is adopted.
Moreover, in the high region, the frequency bandwidth before applying NF
is improved, distortion is decreased, and little distorted play is enabled
over the broadband. Furthermore, NF is made easy to distribute the gain
before applying NF the best for each of each stage, and to apply to high
The characteristic has gathered well, moreover dual FET
which has large gm (mutual conductance), and extremely few noises of itself is
developed and adopted, and high S/N-ization is attained.
which was stabilized very small by adoption of this dual FET as for the drift of
the output end electric potential accompanying direct-current-izing is obtained.
2 monophonic construction which constituted the power source according
to right-and-left channel and two sets of monophonic amplifier on the same
chassis is adopted, and the extensive improvement of the separation is carried
out at the same time it loses the mutual intervention of a power-source part.
The heat sink of 0.35 degree C [ per channel ]/W is attached to the
exterior, and since a cooling effect can take greatly very much, the junction
temperature of a power transistor can be used, stopping it low enough.
Since the speaker change is using the relay for protection as it is, it
does not have a speaker changeover switch and is suppressing the fall of the
dumping factor by the contact resistance of a switch.
||direct-current power amplifier
||Three steps of differential amplification,
the current mirrored live
Three-step Darlington parallel PP (direct-current
|Output (20Hz - 20kHz, THD 0.1%)
|THD (8 ohms, 20Hz - 20kHz)
||0.008% or less (1W output)
|Cross modulation distortion
||0.01% (70Hz : 7kHz = 4:1 or 8ohms)
0.008% or less (at the time of 8 ohms and an Output power)
|Output bandwidth (IHF 0.1%, 8ohms)
||10Hz - 100kHz
|Frequency response (0.5W output)
|Remains noise (input end short-circuit)
||0.15mV or less
|S/N (A network, input end short-circuit)
||120dB or more
||100 (8 ohms, 20Hz - 20kHz) or more
|Conformity load impedance
||Output power: 550W
||Width 425x height 170x depth of 285mm