SANSUI AU-D907Limited

Commentary

Based on the AU-D907, this is a custom model that removes all restrictions and thoroughly pursues both sound and technical aspects. In addition, it is a custom model that uses a lot of know-how and new materials cultivated in the development of AU-X1.

The equalizer circuit has the same 20-chip configuration as the AU-X1.
Coupled with a cascode boot-strap circuit that brings the diamond differential circuit closer to the ideal operation, the dynamic range is expanded.
The MC head amplifier uses an all-FET input and full push-pull input / output circuit, and Pch/Nch FET is used for the element.

Non-ferrous linear high-speed element LAPT (Linear Amp. Power Tr.) is used in two parallel connection, further improving the real value of the diamond differential circuit.
This realizes a high response speed of ± 300 through rate of ± V / μ sec and suppresses the occurrence of TIM distortion to nearly 0.

The power supply section has been strengthened with the theme of high-speed response. In the power supply system, a complimentary service push-pull (shunt) regulated circuit has been newly adopted in place of the conventional constant voltage circuit. This circuit guarantees a stable voltage supply not only when the voltage drops but also when the voltage rises, enabling more stable power supply.
In order to achieve high-grade regeneration, we have changed the case of pure oval and coupling capacitors from aluminum to resin cases, and have also adopted fast recovery diodes for all rectifier diodes.
To further enhance the effect of the pure oval condenser, a 1.2 mm thick brass plate is used for the chassis of the power supply section, which is advantageous in terms of sound quality.
A large toroidal transformer and a large EI transformer are used for the power transformer, and a power cord with a current capacity of 15A for 200W amplifier class is used for the power cord.

The rear panel and chassis are plated with pure copper, the power supply chassis is made of brass plate, and the mounting screws are also treated with bronze to reduce the earth high-frequency impedance.
In addition, the ebony wood case with Everny finish is used to eliminate stray current and create a design flavor.

DC amplifier configuration using full push-pull drive circuit with all-FET input is adopted.
The flat / tone amplifier also uses a 10-chip configuration DC amplifier.

The direct SP output terminal is mounted. System A is directly connected to the DC power amplifier stage with the shortest distance without passing through a changeover switch.

Equipped with a tone jump switch, the equalizer can be directly connected to the power section.

Equipped with DC / AC main amplifier inputs, pre-section and power section can be used independently.

The speaker terminal is a large and reliable screw-in type.

Model Rating

Type	Wide-range DC pre-main amplifier
Power Amplifier Unit
Effective power	100W + 100W (8 Ω, 10 Hz to 20 kHz, THD 0.008%) 100W + 100W (8 Ω, 1 khz, THD 0.003%)
Total harmonic distortion factor	0.008% or Less (10 Hz to 20 kHz, 8 Ω at Effective Output)
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	Not more than 0.008%
Output bandwidth	3 Hz ~ 70 kHz (IHF, double-channel operation, THD0.02%, 8 Ω)
Damping factor	100 (IHF, Double-channel Operation, 1 kHz, 8 Ω)
Frequency Response (1W)	DC ~ 500 khz + 0 -3dB
Input Sensitivity / Impedance (1 kHz)	1V/47k Ω
Signal-to-noise ratio	125 dB or more (IHF, A-network, short circuit)
Channel separation	95 dB or More (IHF, 1 kHz)
Rise time	0.5 μ sec
Slew Rate (8 Ω)	± 200 V / μ sec
Inside Through Rate (8 Ω)	± 300 V / μ sec
TIM Distortion (SAWTOOTH method, 8 Ω)	0.001% or Less (LPF, 100 kHz)
Envelope distortion (8 Ω)	Not more than 0.001%
Preamplifier Section
Input Sensitivity / Impedance (1 kHz)	Phono-1MM : 2.5mV/47k Ω Phono-1MC : 0.1mV/10 Ω Phono-2MM : 2.5mV/47k Ω AUX, Tuner, Tape Play 1, 2 : 150mV/30k Ω
MC compatible impedance	100 Ω or less
Phono maximum allowable input (1 kHz)	Phono MM(THD 0.01%):350mV Phono MC(THD 0.03%):30mV
Output Voltage (1 kHz)	Tape Rec1, 2 (PIN) : 150 mv (at 47k Ω) Pre Out : 1 V at 47k Ω Max Pre Out (THD0. 05%) : 4 v at 47k Ω
Output Impedance (1 kHz)	Tape Rec1, 2 : 600 Ω or less
Total harmonic distortion factor	Phono MC (1 kHz, 6 V) : 0.005% or less Phono MM (20 Hz to 20 kHz, 6 V) : 0.005% or less AUX, Tuner, Tape Play 1, 2 (20 Hz to 20 kHz, 1 V) : 0.005% or less
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	AUX, Tuner, Tape Play 1, 2 (1 v) : not more than 0.005%
Frequency characteristic	RIAA deviation (Phono 1, 2, 20 Hz-20 kHz) + / - 0.2 dB AUX, Tuner, Tape Play 1, 2 : 5 hz to 100 khz, + 0 -1dB
Signal-to-noise ratio (IHF, A-network Short circuit)	Phono MC (input conversion) : -154dBV Phono MM : 90 dB or more AUX, Tuner, Tape Play 1, 2 : 100 dB or more
Channel separation (IHF, 1 kHz)	Phono MC : 70 dB or more Phono MM : 75 dB or more AUX, Tuner, Tape Play 1, 2 : 80 dB or more
Input-to-input separation (input short, 1 kHz)	Tuner ⇔ Phono MM : 90 dB or higher Tape Play 1, 2 ⇔ Phono MM : 90 dB or more Tuner ⇔ Tape Play 1, 2 : 90 dB or higher Tape Play 1 ⇔ Tape Play 2 : 100 dB or more
Tone control	Bass : ± 6 dB (50 Hz) Tone selector (turnover frequency) : 300 Hz, 150 Hz Treble : ± 6 dB (15 kHz) Tone Selector (Turnover Frequency) : 6 khz, 3 khz
Subsonic filter	16 Hz (-3dB, 6dB/oct.)
Audio Muting	-20dB
Headphone jack output	120 mW (8 Ω)
<General>
Load impedance	4 ~ 16 Ω
Rated power consumption (Electrical Appliance and Material Control Law)	260W
External dimensions	Width 466x Height 182x Depth 432 mm
Weight	20.0kg