|235,000 yen(January, 1987 release)
Class-A stereo power amplifier which adopted the whole page push pull full
Balance transmission is applied to the whole system from
an input to an output, and high quality power transmission is enabled.
balance transmission system, since distortion generated with amplifier is also
canceled at the same time it carries a transmission system for exclusive use in
a plus signal and each minus signal and cancels external noise theoretically, a
pure signal ingredient can be taken out.
The Class-A drive system is
adopted and Class-A operation of an input stage and the output stage is carried
In the output stage, the transistor for high bandwidth electric power
magnification of collector loss Pc=80W was constituted from a parallel push
pull, Pc of the unit amplifier of one side was set to a total of 320W, and the
generous output stage is realized.
Moreover, it is considered as the output
stage which can also fully bear low impedance load by giving a margin, and the
ideal drive is aimed at by adopting as a predrive stage the power MOS FET drive
which is an original system of an Accuphase.
The Class-A cascode
differential push pull is adopted as an input stage.
Operation is stable
over [ for the circuit where a cascode circuit is used as an object for high
frequency magnification reason ] a large frequency band, the linearity of an
input is good and the large dynamic range is secured.
part made right and left become independent completely, and has adopted twin
mono-composition with two sets of perfect monophonic amplifier.
eliminated the mutual intervention on either side.
The direct connection
system is adopted as an input.
When the large preamplifier of direct-current
drift etc. is connected, in order to prevent it amplifying and giving a damage
to a speaker, direct-current servo system of Accuphase original is adopted, and
while omitting a direct current, direct-current drift of the amplifier by a
temperature change itself is also stabilized.
The balance input and the
imbalanced input are carried in the input.
Analog type large-sized meter
is carried and an output meter directs a peak value in the guide type meter
which can carry out the Direct reading of dB and the output watt. The Direct
reading of the large power range can be carried out for logarithm compression.
Moreover, the switch with which an operation and proof of meter are cut is
also built in.
It is the design which attached the sideboard of the
natural persimmon to panel finishing of a gold tone scratch hair line.
||Stereo power amplifier
|Output power (both channel operation)
20Hz - 20kHz, 0.02% of a distortion
|2ohm load: 70 W/ch
4ohm load: 80 W/ch
8ohm load: 50 W/ch
16ohm load: 25 W/ch
(20Hz - 20kHz, both channel operation)
|2-4ohm load: 0.02%
8-16ohm load: 0.01%
|At the time of a continuation average output
||Volume maximum: 20Hz-20kHz+0 -0.2 dB
|At the time of 1W output
||Volume maximum: 0.5Hz-200kHz+0 -3.0 dB
Volume 6dB: 0.5Hz-80kHz+0 -3.0 dB
|Input sensitivity (8-ohm load)
||At the time of a continuation average
At the time of 1W output: 0.11V
|S/N ratio (A-compensation)
|At the time of input short-circuit and a
continuation average output
||Balanced input: 120dB
|At the time of input 1kohm and 1W output
||Balanced input: 100db
|Power output meter
||A logarithm compression type, -40dB-+3dB, and an output Direct-reading scale
|The semiconductor used
||Transistor: 81 pieces
FET: 16 pieces
IC: Eight pieces
Diode: 89 pieces
||At the time of no inputting: 245W
Electrical Appliance and Material Control Law: 255W
At the time of an
8ohm load Output power: 300W
||Width 475x height 170x depth of 408mm