Audio Database


SANSUI AU-alpha 907Limited * 2000-set limited production
410,000yen(1994 release)

The Integrated Amplifier of the 3rd generation of the Limited which deviated to neither the circuitry nor the organization nor the part, but elaborated all, and was made.

The HYPER alpha-X balance circuitry of the whole page wide-range DC amplifier stream composition which made the alpha-X balance amplifier technology original with an SANSUI concentrate by higher-order origin is carried.
In order to stop the dynamic noise in a circuitry to the minimum, the Wilson current mirror quantity CMRR type constant current circuit was included in the first rank of power amplifier and a preamplifier, and the with a theoretical value of 140dB modification effect is realized by CMRR.
Moreover, MOS FET (2SK405/2SJ115) of the old model is chosen as an amplification element.

In C-2302 VINTAGE which is a highest-end model of that time of an SANSUI, it was used for the power amplifier part, and the Teflon substrate the high tone-quality modification effect was proved to be is adopted as it for the first time by the pre-main.
electromagnetic waves fly according to the property that the dielectric constant and dielectric dissipation factor of Teflon are very small -- etc. -- the ill effect to the passage signal in a circuitry is canceled.
And the vibrational absorption capacity by an internal loss was used, and the interference to the tone quality by the oscillation in a circuitry is also prevented.

The closed-loop stream composition made to become independent of a grounding is used for a power-source part so that it may be stabilized and a large current can be supplied.
Each stages, such as a power stage and a voltage amplification stage, were separated completely, and the cross interferencee is prevented.
Moreover, since a power transformer puts low leakage flux-ization into practice, it enclosed the high-density fill with the interior by having made the shielding case into the quadruplicate structure, and has realized enlargement of 13kg of total weights. 1 following and the sub- have adopted as a drawer lead the OFC lead which thought the tone quality as important.
Furthermore, an electrolytic capacitor is also developed newly and it has become a thing of custom-made ellipse form.

An oscillation was not blindly held down with a heavy chassis, but the strengthening twin monophonic construction which maintained the optimal weight balance of the set is adopted as the basis of the concept of realizing the case design taken into the numeration to the property of an oscillation.
The interference of the natural oscillation generated by the power supply system and a signal system is negated according to the effect of the layout.

An original isolation theory which utilized Teflon material and pure-copper material is established as a measure against various oscillations generated by the electric, mechanical operation, etc., and the tone transition generated from the physical properties of a material.
Based on this, each fraction or part which constitute amplifier are not caught separately, but the occurrence and the propagation of the oscillation are intercepted and controlled in total from the viewpoint to which all were made to link.

In the insulator, in order to absorb the interior and a foreign unnecessary oscillation effectively, pure-copper material with the outstanding damping characteristics was cut, the gilding treatment was carried out, and it has adopted.
Furthermore, a Teflon sheet is inserted between pure-copper sole plates, and a stability and vibration suppression nature are raised much more, such as sticking felt on a setting fraction.
Moreover, the aluminum bonnet of the 6mm thickness which gave the coating containing copper powder was fixed on Teflon material and a gilding screw, and the rigidity of a case is strengthened.

He examines the part for tone qualities synthetically, repeating viewing and listening so that an unnecessary colorlation may not be added, and all likelihoods of preventing an occurrence of distortion, a noise, and a loss, such as using a high purity 6N copper belt for a power-source part, are examined.

The OFC composition and the 24k hardening gilding termination made from German WBT which is proud of elaborateness with a cutting precision of 2/100mm or less are adopted as connection to a speaker.
A banana plug or not only a very-thick speaker cable but the bi-wiring interconnection is supported.

Functionalities, such as a power amplifier direct, a source power direct, a phone equalizer (MC, man month), and an REC serector, were carried, and ten gilding input terminals are offered.

Internal Power
The The

Rating of a mode
Form Integrated amplifier
<Power amplifier part>
Effective output (10Hz - 20kHz)
Both channel simultaneous operation
6ohm: 100W+100W
8ohm: 80W+80W
THD (at the time of an effective output) 0.01% or less (8ohms)
Frequency characteristic (1W) DC-300kHz and +0 -3dB
Cross modulation distortion 0.01% or less (8ohms)
Dumping factor 150 (8ohms)
Input sensitivity/impedance 1V / 5kohm (1kHz)
SN ratio (A network) 120dB or more
Dynamic power 6ohm: 100W
4ohm: 130W
2ohm: 170W
TIM distortion (SAWTOOTH) Below a limit-of-measurement value
Slew rate 200v/microsec
Rise time 0.5microsec
<Pre part>
Input sensitivity/impedance
Phono man month: 2.5mV / 47kohm
Phono MC: 300 microvolts/100 ohms
compact disk, Tuner, Line, 1-2:150mV of Tape/DAT / 20kohm
Phono maximum permissible input MM(THD 0.01%):250mV
MC(THD 0.1%):25mV
the frequency characteristic (1W) Phono man month: 20Hz - 20kHz, ±0.2dB
compact disk, Tuner, Line, Tape/DAT-1 and 2: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, 2:110dB or more
Subsonic Filter 16Hz (-3dB), 6dB / oct
Loudness 50Hz:+4dB
Power dissipation 280W
Dimensions Width 466x height 166x depth of 453mm
Weight 34.0kg