Audio Database

The

SANSUI AU-alpha 907KX
270,000yen(1992 release)

Description
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The Integrated Amplifier which adopted the Advanced alpha-X balance circuitry.

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.

From 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.

The NEW alpha-X balance power source is adopted as a power-source part.
The 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.
Moreover, it has dissociated completely and each stage, such as a power stage and a voltage amplification stage, has also adopted the thing of a high-quality sound using as the electrolytic capacitor for power sources, or first recovery diode.
The large-sized power transformer of 13kg of total weights and minute leakage flux which enclosed the high-density fill with the interior of a quadruplicate structure is adopted as a power transformer.

The 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.

Moreover, the vibration suppression parts made from a pure copper and Teflon material, such as an insulator of a rolling copper platform, a copper plating rear panel, and a pure-copper Naked, a special coating bonnet, and the pure-copper base, are used.

It has selected carefully and adopted from the high-quality sound part obtained by the development of the Vintage series of an SANSUI.
Various 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.
In AU-alpha 907KX, ARS, ARSA, AWF, the golden plating bars GUG, SAG, and GSG, the film capacitor, the special styrene capacitor, the coil containing a copper case, the RMG gilding resistor, etc. are adopted.
Moreover, the copper plating screw is adopted as the installment screw of the front panel.

The power amplifier direct input which equipped the balance / normal input is carried.

A source power direct, 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.

Rear
Internal
A DC
The Power

Rating of a mode
Form Integrated amplifier
<Power amplifier part>
Effective output (20Hz - 20kHz)
Both channel simultaneous operation
190W+190W (6ohm)
160W+160W (8ohm)
THD (at the time of an effective output) 0.003% or less (8ohm)
Cross modulation distortion 0.003% or less (8ohm)
Dumping factor 150 (8ohm)
Frequency characteristic (1W) DC-300kHz+0 -3dB
Input sensitivity/impedance 1V / 5kohm (1kHz)
SN ratio (A network) 120dB or more
Dynamic power 580W (2ohm)
390W (4ohm)
310W (6ohm)
TIM distortion (SAWTOOTH) Below a limit-of-measurement value
Slew rate 200v/microsec
Rise time 0.5microsec
<Pre part>
Input sensitivity/impedance
(1kHz)
Phono man month: 2.5mV / 47kohm
Phono MC: 300 microvolts/100 ohms
compact disk, Tuner, Line, Tape/DAT1-2-3:150mV /, 20kohm
Phono maximum permissible input MM(THD 0.01%):210mV
MC(THD 0.1%):21mV
the frequency characteristic (1W) Phono man month: 20Hz-20kHz}0.2dB
compact disk, Tuner, Line, Tape/DAT-1, 2 and 3:DC-300Hz, and +0 -3 dB
SN ratio (A network) Phono man month: 90dB or more
Phono MC: 75dB or more
compact disk, Tuner, Line, Tape/DAT-1, 2-3:110dB or more
Tone control The BASS maximum variation: }5dB (50Hz)
The TREBLE maximum variation: }5dB (15kHz)
Subsonic Filter 16Hz (-3dB), 6dB / oct
Loudness 50Hz:+4dB
10kHz:+3dB
<Synthesis>
Power dissipation 400W
Dimensions Width 460x height 161x depth of 446mm
Weight 33.0kg