Audio Database

The

SANSUI AU-D707
95,000yen(around the 1979 time)

Description
@
DC Integrated Amplifier of three-dimensionalC amplifier stream composition which carries a diamond operation circuitry also in an equalizer part.

Each of equalizer parts, flat amplifier / tone amplifier parts, and power amplifier parts has adopted the direct couple scheme which is DC amplifier stream composition and banished the input capacitor of the whole-block stage.
By straight DC amplifier stream composition, pure transmit of a music signal and thorough wide-range-ization are attained.
The input of the whole-block stage is an FET input of a low-noise high and gm property, and is a full push pull input circuit.
Moreover, each block stage is decreasing a harmful dynamic distortion sharply by candidate circuitry.

The power amplifier part has followed the circuitry of AU-D907.
That is, drive capacity of the predrive stage is made more powerful by the diamond differential circuit by the dual complimentary which has improved the dynamic behavior for the operation circuitry with constant current of the Dual-FET using which is excellent in a low-noise property at the first rank, and can send a large current in the 2nd step.
Moreover, NM (Non Magnetic) transistor excellent in the linearity of SANSUI custom is used for a power stage, and a dynamic behavior is good and is considering it as the symmetrical circuitry which was excellent also in tone quality.

MC head amplifier has perfect symmetrical type push pull composition of the performance stabilized also to the transitional input.
The low-noise transistor by P channel and N channel combination which were selected carefully was used for the first rank, and the original symmetrical symmetrical-network stream composition has realized the improvement in a dynamic behavior.

The direct couple scheme which removed the input capacitor which causes tone-quality prevention is used for an equalizer amplifier, and it carries the diamond differential circuit.
The first rank is a low-noise, and the cascode interconnection and the differential circuit with constant current which use the Dual FET of a high and gm, and an electric-current differential push-pull circuit with a current mirror and the stage of an output are the SEPP stream compositions by a two-step Darlington connection, and, as for the 2nd step, it is aiming at the reduction of TIM distortion.

A flat / tone amplifier has DC amplifier composition of the direct couple scheme which eliminated the input capacitor.
The first rank is the cascode interconnection and the differential circuit with constant current which use the Dual FET of a low-noise, and a high and gm, is a SEPP stream composition [ according / an output stage / to a two step Darlington connection ] according [ the 2nd step ] to an electric-current differential push-pull circuit with a current mirror, and is aiming at the reduction of TIM distortion.
Moreover, a tone control circuit is good CR type of a variable property, and the tone selector and the conjointly gentle property are acquired.
At the time of a jump switchpoint using, a signal jumps flat amplifier and goes into a power part directly.

EI transformer is adopted as a power-source part.
A supplying in a power amplifier part adopts exclusive 2 coil to which full independence of the left channel and the right channel was carried out, and two rectifier circuits, and is using the mass electrolytic capacitor (15,000micro-Fx4) and the metallized capacitor.
Moreover, to a preamplifier part, the voltage stabilizer by the coil only for another is adopted, and while suppressing an occurrence of TIM distortion or envelope distortion, consideration is carried out to the member which leads to improvements in a tone quality, such as an improvement in resolution.

A two-line interconnection of OFF, A, B, and A+B is possible for a speaker system, if it is used by A system, it will be connected to DC power amplifier stage and a direct by the shortest distance not passing through a speaker changeover switch, and the high tone quality of a quality is obtained.

A Subsonic Filter (16Hz-3dB, 6dB / oct), a loudness switchpoint, the tone jump switchpoint, the balance control, 2 circuitry tapes play / copy function is carried.

Standby AC plug socket 3 circuitry (interlocking 1 circuitry 100W, 2 non-interlocking circuitry 250W)

Grounding terminal loading

A pre, a power separation possible

A Power
DC
Block

Rating of a mode
Form Wide-range DC Integrated Amplifier
<Power amplifier part>
Effective output 90W+90W (10Hz - 20kHz, THD 0.008%, 8ohm)
90W+90W (1kHz, THD 0.003%, 8ohm)
THD 0.008% or less (at 10Hz - 20kHz, the time of an effective output 8ohm)
Cross modulation distortion (70Hz:7kHz=4:1) 0.008% or less
Output bandwidth 3Hz - 70kHz (IHF, both channel operation, 1kHz, 8ohm)
Dumping factor 100 (IHF, both channel operation, 1kHz, 8ohm)
Frequency characteristic DC-500kHz and +0 -3dB
Input sensitivity/impedance (1kHz) 1V/47kohm
SN ratio 125dB or more (IHF, A network, a short circuit)
Channel separation (IHF, 1kHz) 90dB or more
Rise time 0.5microsec
Slew rate }200v/microsec
<Preamplifier part>
Input sensitivity/impedance (1kHz) Phono-1 man-month:2.5mV /, 47kohm
Phono-1 MC: 0.1mV/100 ohm
Phono-2 man-month:2.5mV /, 47kohm
AUX, Tuner, Tape Play 1, 2 (PIN):150mV / 47kohm
MC conformity impedance 100ohms or less
Phono maximum permissible input (1kHz) Phono MM:350mV(THD 0.01%)
Phono MC:30mV(THD 0.03%)
Output voltage (1kHz) Tape Rec 1, 2 (at time of PIN and 47kohm):150mV
Pre Out(at the time of 47kohm): 1V
Max Pre Out(at the time of THD 0.05% and 47kohm): 4V
Output load impedance (1kHz) Tape Rec 1, 2:600ohms or less
THD Phono MC (1kHz, 6V): 0.01% or less
Phono man month (20Hz - 20kHz, 6V): 0.005% or less
AUX, Tuner, Tape Play 1, 2 (20Hz - 20kHz, 1V):0.005% or less
Cross modulation distortion (70Hz:7kHz=4:1) AUX, Tuner, Tape Play 1, 2 (1V):0.005% or less
Frequency characteristic RIAA deflection (Phono 1, 2 or 20Hz - 20kHz): }0.2dB
AUX, Tuner, Tape Play 1, 2:5Hz - 100kHz, and +0 -1 dB
SN ratio (IHF, A network)
Short circuit
Phono MC(input conversion): -154dBV
Phono man month: 90dB or more
AUX, Tuner, Tape Play 1, 2:100dB or more
Channel separation (IHF, 1kHz) Phono MC: 70dB or more
Phono man month: 70dB or more
AUX, Tuner, Tape Play 1, 2:80dB or more
The separation between inputs
(Input short-circuit, 1kHz)
Tuner<=>Phono man month: More than 90dB
Tape Play 1, 2 <=>Phono man month: 90dB or more
Tuner<=>Tape Play 1, 2:90dB or more
More than Tape Play 1 <=>Tape Play 2:100dB
Tone control Bass: }6dB (50Hz)
Tone selector (turnover frequency): 300Hz, 150Hz
Treble: }6dB (15kHz)
Tone selector (turnover frequency): 6kHz, 3kHz
Subsonic Filter 16Hz (-3dB, 6 dB/oct)
Loudness (volume -30dB o'clock) +10dB(50Hz)
+4dB(10kHz)
Headphone jack output 120mW (8ohm)
<Synthesis>
Load impedance 4-16ohm
Power dissipation (Electrical Appliance and Material Control Law) 230W
Dimensions Width 430x height 168x depth of 428mm
At the time of a rack-mounted adapter attachment: Width 482x depth of 455mm
Weight 20.1kg
At the time of a rack-mounted adapter attachment: 20.6kg
Option Rack-mounted adapter BX-7 (1 set, 3,000yen)