Audio Database

The

SANSUI AU-D907
142,000yen(around the 1979 time)

Description
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DC Integrated Amplifier which carries the diamond operation circuitry original with an SANSUI which investigated the dynamic distorted modification for the purpose of the useful music play.

Both the equalizer part the flat amplifier / tone control part and the power amplifier part are considered as DC amplifier stream composition of the push pull output which raised the nakedness property.
Furthermore, for tone-quality pursuit, the input capacitor of the whole-block stage is eliminated, the direct couple scheme by a whole page FET input is adopted, and a pure transmit and wide-range-izing of the music signal are attained.
The thing of a low-noise, and a high and gm property is chosen, in addition it is a symmetrical symmetrical-network stream composition, each block stage decreases a harmful TIM distortion and envelope distortion sharply, and all used FETs are aiming at the improvement in a tone quality.

The power amplifier part serves as a power stage and a drive circuitry by a three-step amplification stream composition.
The first rank is an operation circuitry with constant current of the Dual-FET using which a large current can pass by a low-noise,The diamond operation circuitry (PAT.PEND) by the dual complimentary which suppressed the occurrence of TIM distortion by drive capacity with the 2nd step of powerful predrive stage, and the 3rd step are an electric-current operation push-pull circuit.
NM (Non Magnetic) transistor of SANSUI custom is used for the last power stage, and the whole circuitry constitutes it from a symmetrical symmetrical network.

MC head amplifier part is a candidate circuitry by the push pull input/output circuitry of SANSUI original, and serves as a direct couple scheme.
The first rank used new style FET of the newly developed low-noise, P channel by a high and gm, and N channel combination according to the Para interconnection in large numbers, and has realized the operation stabilized from the minute input to the transitional Dainyuu power by right-and-left channel independent-source supplying.
Furthermore, candidate circuitry has improved the dynamic behavior sharply.

An equalizer amplifier is the direct couple scheme which removed the input capacitor which has on a tone quality, and also carries the diamond operation circuitry.
The first rank is a low-noise, a high and gm, the operation input circuit of a Dual-FET using, and with a cascode bootstrap + constant current circuit,The 2-3rd step has realized the diamond operation circuitry + electric-current operation push pull, electric-current margin with a stage of an output sufficient by the SEPP circuit by a Darlington connection, and the low-power-output impedance.
Moreover, candidate form circuitry has improved dynamic distortion sharply.

A flat / tone amplifier also has DC amplifier composition of a direct couple scheme.
The first rank is the cascode interconnection and the operation circuitry with the current source which use the Dual FET of a low-noise, and a high and gm, and the 2nd step has adopted the electric-current operation push-pull circuit with a current mirror.
It has the composition that the open loop property aiming at a reduction of TIM distortion was excellent like DC power amplifier part.
Moreover, it is also possible to jump in a power part directly from an equalizer amplifier with a jump switchpoint.

The high regulation large-sized toroidal transformer by two coils which made the right-and-left channel of the power stage become independent to the powering to a power amplifier part, and two rectifier circuits is used.
The right-and-left channel independent 2 power-source scheme by EI transformer is adopted as the predrive stage, and it has become a 4 in all power-source scheme.
Moreover, to DC flat amplifier part, the independent supplying is carried out by the stabilizing supply from MC head amplifier part.

Direct speaker output-terminal. A two-line interconnection of OFF, A, B, and A+B is possible for a speaker system.
A system is especially connected with DC power amplifier stage by the shortest distance direct not passing through a changeover switch.

Functionalities, such as a Subsonic Filter (16Hz-3dB, 6dB / oct), an audio muting (-20dB), a tone jump switchpoint, a balance control, 2 circuitry tapes play / copy function, and an input selector with an indicator, are carried.

The Phono input terminal serves as gilding finish.

By pre-main separation, a preamplifier part and a power amplifier part are independent enables, respectively.

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

Grounding terminal

Rear
A An
Block

Rating of a mode
Form Wide-range DC Integrated Amplifier
<Power amplifier part>
Effective output 100W+100W (10Hz - 20kHz, THD 0.008%, 8ohm)
100W+100W (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) 95dB 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 ohms
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): 0.005% 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: 75dB 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)
Headphone jack output 120mW (8ohm)
<Synthesis>
Load impedance 4-16ohm
Power dissipation (Electrical Appliance and Material Control Law) 250W
Dimensions Width 430x height 168x depth of 428mm
At the time of a rack-mounted adapter attachment: Width 482x depth of 455mm
Weight 20.8kg
At the time of a rack-mounted adapter attachment: 21.2kg
Option Rack-mounted adapter BX-7 (1 set, 3,000yen)