Audio Database

The

SANSUI AU-alpha 777DG
96,500yen(around the 1989 time)

Description
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The Integrated Amplifier which carries the digital analog converter of a MASH scheme.

New L.D.C.S (linear & direct D/A combartion system) by a MASH scheme is carried in the D?A converter part.
A MASH scheme is a D-A-conversion scheme made into the criteria of a translation of the frequency by a crystal oscillator,By high order oversampling and the 3rd noise shaping, a digital signal is changed into an analog signal highly precise in an instant, and the occurrence of zero cross distortion or non-linear distortion has the special feature of not occurring theoretically.
In AU-alpha 777DG, in order to employ the high precision of a MASH scheme efficiently, the precision near a crystal oscillator is offered, and also a lock range adopts a large LT element, and it is considered as the original linear & direct D/A combartion system (L. D.C.S).
In New L.D.C.S, total upgrade is aimed at from the off-site circuitry, and the SN ratio is improved further.

In the power-source part, the transformer for exclusive use is carried in each of a digital circuit and an analog circuit, and the separation put into practice from the power-source part is performed.
This has prevented mixing to analog parts, such as an electromagnetic-wave pulse peculiar to digital one.

The alpha-X balance circuit which poured the original know-how into the amplifier part is adopted, and the circuitry itself has canceled a noise and distortion by balance operation.

The power-source part was placed in the center and the twin monophonic construction which arranges a power unit symmetrically is adopted. Since a digital circuit part is shielded and arranged on the outside of the left channel unit and also an analog input part is shielded and arranged by this on the outside of the right channel unit, the digital part and the analog part are separated clearly.

Since it is compatible in a tone quality and convenience, the remote controller which adopted the direct-access rotary switch is attached, and the volume up and down by a 6-unit volume and a source changeover are possible.

Functionalities, such as Source-Direct operation, an REC serector, and a direct-access rotary switch, are carried.

The gilding input terminal, the polar attached-indicator very-thick power cord, and the AC outlet are adopted.

There was sub- wood as an option.

Internal Digital
Remote Option

Rating of a mode
Form Alpha-X balanced integrated amplifier
<Digital part>
Frequency characteristic 4Hz-20kHz}0.5dB
SN ratio 108dB or more (EIAJ)
RF distortion 0.003% or less
Digital input level 0.5 Vp-p/75ohms
An optical input 660nm (light-generation wavelength)
<Power amplifier part>
Effective output (10Hz - 20kHz)
Both channel operation
105W+105W (6ohms)
90W+90W (8ohms)
Dynamic power 230W (2ohms)
220W (4ohms)
155W (6ohms)
THD (at the time of an effective output) 0.003% or less (8ohms)
Cross modulation distortion 0.003% or less (8ohms)
Dumping factor 150 (8ohms)
Frequency characteristic (1W) DC-200kHz+0 -3dB
TIM distortion (SAWTOOTH) Below a limit-of-measurement value
Slew rate 180v/microsec
Rise time 0.6microsec
<Preamplifier part>
Input sensitivity/impedance
(1kHz)
Phono man month: 2.5mV / 47kohm
Phono MC: 300 microvolts/100 ohms
compact disk, Tuner, Line, Tape/DAT1, 2 or 3:150mV / 20kohm
Phono maximum permissible input MM(THD 0.01%):210mV
MC(THD 0.1%):21mV
Frequency characteristic Phono man month: 20Hz-20kHz}0.2dB
compact disk, Tuner, Line, Tape/DAT1, 2, and 3:DC-200kHz+0 -3 dB
SN ratio (A network) Phono man month: 88dB or more
Phono MC: 70dB or more
compact disk, Tuner, Line, Tape/DAT1, 2 or 3:110dB or more
Tone control Bass: }6dB (50Hz)
Treble: }6dB (15kHz)
Subsonic Filter 16Hz (-3dB), 6dB / oct
Loudness + 6dB (50Hz), +4dB (10kHz)
<Synthesis>
Power dissipation 250W
Dimensions Width 430x height 163x depth of 450mm
Weight 18.2kg
Adjunct Wireless remote control RS-1130
Option Real sub- wood SW-AU1 (10,000yen)