Audio Database

The

SANSUI AU-alpha 707NRA
200,000yen(1998 release)

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

The Ultimate alpha-X balance circuitry has realized operating environment which is transmit / amplification it1 in which it results in an output from the input of the first rank, the driver stage, and a final stage, and was excellent by raising the current margin of the driver stage twice over the past, and carrying out a first class operation.

The NEW diamond differential circuit which can take out the output of +- without phase inversion is adopted as the driver stage. It has the current-supply-source capacity to have excelled also to the momentary input signal by this, and the occurrence of a harmful TIM distortion is suppressed on Hearing impression.

Moreover, the NM-LAPT single push pull scheme is adopted, and the speaker is driven on the same requirements from both of positive/negative by arranging amplifier on + and - of a right-and-left channel of an output stage, respectively.

With the mechanical floating scheme which carried out the floating of the mounting of a power transformer from the chassis, it has the structure where an oscillation of a power supply system does not get across to a chassis.
Moreover, the occurrence of the oscillation is suppressed to the relative minimum by adopting a new model-like radiator.
Furthermore, it has a strong structure to the oscillation by making a floating mounting sub- wood which embedded the pure-copper board on 3 splitting bonnet.
An ellipse-shaped thing is adopted as an insulator and the oscillation is distributed effectively.

The alpha-X balance power source is adopted as a power-source part.
It has closed-loop composition of full independence from the grounding which made the output stage the balanced type closing, and used the first rank as the upper-limit symmetrical balance type constant current type power source, and the transformer sub- side also made another coil.

The master volume was attached to the pure-copper board by the isorated mechanical feedback, and the 6-unit master volume which controlled the oscillation is used for it.

It is possible to link directly the source connected to three direct inputs with a power amplifier part.

The balance input is carried.

The polar attached-indicator power cord is adopted.

Rear 6-unit
Internal Power
Block

Rating of a mode
Synopsis Integrated amplifier
<Power amplifier part>
Effective output (10Hz - 20kHz)
Both channel simultaneous operation
160W+160W (6ohm)
130W+130W (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 / 10kohm (1kHz)
SN ratio (A network) 120dB or more
Dynamic power 405W (2ohm)
320W (4ohm)
210W (6ohm)
TIM distortion (SAWTOOTH) Below a limit-of-measurement value
Slew rate 200v/microsec
Rise time 0.5microsec
<Preamplifier part>
Input sensitivity/impedance
(1kHz)
Phono man month: 2.5mV / 47kohm
Phono MC: 300 microvolts/100 ohm
compact disk, Tuner, Line, micro disk/Tape1, Tape2:150mV/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, micro disk/Tape-1, Tape-2:DC - 300kHz+0 -3 dB
SN ratio (A network) Phono man month: 88dB or more
Phono MC: 70dB or more
compact disk, TUner, Line, micro disk/Tape-1, and more than Tape2:110dB
Tone control The Bass maximum variation: }6dB (50Hz)
The Treble maximum variation: }6dB (15kHz)
Subsonic Filter 16Hz (-3dB), 6dB / oct
Loudness +6dB(50Hz)
+4dB(10kHz)
<Synthesis>
Power dissipation 330W
Dimensions Width 462x height 165x depth of 446mm
Weight 23.6kg