|SANSUI AU-alpha 907i
The stereo Integrated Amplifier which adopted the alpha-X balance circuit.
An alpha-X balance circuit is a scheme transmitted and amplified with the
exclusive amplifier which became independent to both by the side of + of
a signal, and -, and since it has dissociated with the grounding, it is
suppressing the noise and the distorted influence from a grounding theoretically.
Moreover, the power part input stage is considered
as the differential balance input stream composition which uses low-noise FET, and since inphase component removal ratio:CMRR (Common Mode Rejection Rato) by
the side of + of a signal system and - is large, the circuitry itself has
canceled an inphase noise and distortion.
Moreover, in order to drive from
the bothways by the side of + side - rather than to drive between an amplifier
output and a grounding like the conventional amplifier, a power supply system
noise did not mix but the occurrence of IHM (Interface Hum Modulation) by the
counter-electromotive force from a speaker is prevented.
balance power source which was made to become independent of a grounding and was
made into the closed loop is used for a power-source part.
+ While an
electric current is equal and always prevents the ill effect to the signal by
the unbalance of a power source by the side and - side, it is a design strong
also against the noise and power supply variation from AC line.
the transformer, vibration proof and thermal resistance were strengthened with
the high-density fill -- the large-sized transformer is overly carried.
Moreover, the custom-made electrolytic capacitor only for an audio with a
quick charge-and-discharge speed and large-current capacity first recovery diode are adopted.
In addition to the master regulator who combines with a
power transformer, the twin regulator system which has stationed the local
regulator on a phone equalizer substrate and a preamplifier substrate is
For the regulator of a two-step stream composition, it is strong to
a power supply variation or a load variation, and the stable clean powering is
The power-source part which makes a power transformer an
entity was set in the center, and the twin monophonic construction which has
arranged the power amplifier part symmetrically with the right and left is
Furthermore, the De Dis Pau Shal substrate which cuts a detailed
oscillation of a substrate is adopted as the substrate of a power part.
The solid & anti flux chassis which the work which eliminates an
oscillation and an interference of a noise was made is used for the chassis.
While carrying out the full separation shielding of each stage with a separator,
five large-sized insulators (certain-factor5 insulator) by which loading
distribution was carried out the optimal are used.
A volume has little
tone-quality failure, it has adopted the small high precision 6-unit Detent type
volume of a right-and-left interlock error as it, it can narrow down to it to
near -90dB, and the SN ratio on a package is improved.
equalizer of a discrete stream composition is used for the equalizer part for
The tone control with a defeet is carried.
balance input in which high balance transmit and amplification of a purity are
possible, and the power amplifier direct functionality are carried.
Subsonic Filter, a muting, and the accessories circuitry of a balance control
are passed, and the Source-Direct functionality which links all the input
sources with the predrive stage directly is carried.
||Alpha-X balance integrated amplifier
|<Power amplifier part>
|Output power (20Hz - 20kHz)
Both channel drive
|THD (at the time of an effective output)
||0.003% or less (8ohm)
|Cross modulation distortion (at the time of
an effective output)
||0.003% or less (8ohm)
|Frequency characteristic (1W)
||Balance, Normal:1V/3kohm (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, Prosessor,
Tape/DAT/Play1-2-3:150mV /, 47kohm
|Phono maximum permissible input
||Phono man month: 20Hz-20kHz}0.2dB
compact disk, Line, and Tape/DAT/Play1-2-3:DC-300kHz+0 -3 dB
||Phono man month: 90dB or more
75dB or more
Tuner, Line, compact disk, and more than
||The Bass maximum variation: }5dB (50Hz)
The Treble maximum variation: }5dB (15kHz)
Turnover frequency: 75Hz,
||16Hz (-3dB), 6dB / oct
||Width 448x height 160x depth of 441mm