|SANSUI AU-alpha 707KX
The Integrated Amplifier of 707 serieses which
adopted the Advanced alpha-X balance circuitry.
The technology introduced is
almost the same as AU-alpha 907KX, and has adopted the newly developed thing as
The transmit and the amplification of a signal have
balance composition performed simultaneously, and since the amplifying circuit
and grounding circuitry of amplifier are separated completely, the Advanced
alpha-X balance circuitry is intercepting the inphase distortion of a reverse
electromotive style or an exogenous noise which the circuitry itself generated
in the speaker side.
Moreover, a total of four exclusive amplifier is + at +
[ of an output ], and - side. - With the push pull scheme to which a speaker is
made to drive on the same requirements from both, the low distortion is realized
and the dynamic frequency characteristic is sharply raised by lowering the
impedance of a circuitry.
The RF property and electric-current threshold
value which nonmagnetic embodying was thoroughly carried out and were excellent
in pure-copper material have been acquired until it carries NM-LAPT developed
only in the audio in the power stage and results in a bonding wire.
the input to the output, a whole page is considered as a wide-range DC amplifier
stream composition, expansion of the frequency characteristic in a nakedness
property, improvement in a phase response, and reduction-ization of a distortion
are performed, and NFB is stopped to the minimum.
The NEW diamond differential circuit which can take out the output by the
side of - without phase inversion is adopted as a power stage, and the
occurrence of TIM distortion is suppressed by the early response to the
input of a momentary signal.
Furthermore, the circuitry is made to form into wide-range high speed by
carrying out cascade connection of the FET of the first rank.
alpha-X balance power source is adopted as a power-source part.
unbalance of the power source which causes a tone-quality failure as a closed
loop made to become independent of a grounding is stopped few.
power-source part was placed in the center of amplifier, the twin monophonic
construction which has arranged the power unit symmetrically to the right and
left was adopted, and the optimal weight balance as the structure is maintained.
In order to control an oscillation and vibration of amplifier, the
isorated mechanical feedback is introduced.
The vibration suppression
isolation part made from a pure copper is adopted as oscillating channels of
communication, such as between a master volume and chassis and between a power
transistor and radiators.
Furthermore, an internal loss sticks a Teflon
tapes for the Teflon sheet which was greatly excellent in vibrational absorption
capacity between a radiator, a bonnet, and a chassis etc. between an insulator
and a sole plate, and is carrying out the isolated rate of the oscillation.
The newly developed special structure insulator is fixed on the copper
plating screw, and the tone-quality failure by oscillation is suppressed.
It has selected carefully and adopted from the high-quality sound part
obtained by the development of the Vintage series of an SANSUI.
management -- the signal passed directly, has adopted the golden plating bar
resistor as the important fraction which affects a tone quality on a circuitry, and also especially makes the film capacitor of a power-source part a golden
plating bar -- is performed, and the pure sound is pursued.
copper plating screw is adopted as the installment screw of the front panel.
The source power direct is carried and all the line inputs can be
directly linked with a power amplifier part.
An REC serector, 11 all
gilding input terminals, a 6-unit Detent volume, real sub- wood, a polar
attached-indicator power cord, etc. are adopted.
|<Power amplifier part>
|Effective output (10Hz - 20kHz)
Both channel simultaneous operation
|THD (at the time of an effective output)
||0.003% or less (8ohm)
|Cross modulation distortion
||0.003% or less (8ohm)
|Frequency characteristic (1W)
||1V / 5kohm (1kHz)
|SN ratio (A network)
||120dB or more
|TIM distortion (SAWTOOTH)
||Below a limit-of-measurement value
|Phono man month: 2.5mV / 47kohm
Phono MC: 300 microvolts/100 ohm
compact disk, Tuner, Line, Tape/DAT1-2-3:150mV
|Phono maximum permissible input
|the frequency characteristic (1W)
||Phono man month: 20Hz-20kHz}0.2dB
compact disk, Tuner, Line, Tape/DAT-1, 2 and 3:DC-200Hz, and +0 -3 dB
|SN ratio (A network)
||Phono man month: 88dB or more
70dB or more
compact disk, Tuner, Line, Tape/DAT-1, 2-3:110dB or more
||The BASS maximum variation: }6dB (50Hz)
The TREBLE maximum variation: }6dB (15kHz)
||16Hz (-3dB), 6dB / oct
||Width 460x height 161x depth of 446mm