4K HDR Video Demos:
youtu.be/WOMYIqfdICU
youtu.be/2NrFFai7y5k

Ultimul amplificator integrat (cap de serie/hi-end) de la SANSUI lansat in 1998.
Totul este la superlativ, dinamica absolut fabuloasa similara separatelor high end, bass autoritar dar perfect controlat inclusiv in pasajele congestionate in alte configuratii, sunet corpolent, voluminos, cu textura excelenta in zona de medii etc, inginerii de la Sansui au pus aici doar componente de top, gen transformatorul TAMURA de 13 kg ravnit de audiofili, circuitul Ultimate Alpha X balance, etc.
Gasiti mai multe opinii pe net.
Evident acest model nu a fost niciodata produs pentru Europa sau Statele Unite, fiind disponibil doar in versiunea de 100V. In pret se include si un transformator silentios de la 220-240V la 100V facut de Nissyo in Japonia, cu o capacitate de min 550W, aproape dublul consumului maxim al acestui amplif.

Doar preluare personala din Cluj, cu auditie prealabila, amplificatorul cantareste 33 kg si se adauga inca 6kg transformatorul. Usor negociabil.

audio-database.com/SANSUI/amp/au-alpha907nra-e.html

Pre-main amplifier with Ultimate α -X balance circuit.

With the Ultimate α -X balance circuit, the current margin of the driver stage has been raised to twice that of the conventional one to achieve A-class operation, and excellent dynamic characteristics, wide range and high speed have been achieved in all stages of transmission and amplification.

The the final stage, the talk configuration has been changed to single-drive balanced push-pull, and an NM-LAPT with a Pc (collector loss) of 200W, which is suitable for high-power amplification, as used in the power amplifier B-2302, is installed. This improves the current margin during actual operation and enables excellent reproduction.

A power transformer with a total weight of 13 kg is used for the power supply.
By sealing high-density filler inside the four layered shield structure, vibration during operation is suppressed and stable current supply capability is improved.
In addition, the mechanical floating system that floats the power transformer from the chassis prevents the vibration of the power system from being transmitted to the chassis.

By adopting a new shape radiator, the generation of vibration is minimized.
In addition, a newly developed 3-part bonnet containing a newly shaped copper powder that reduces vibration and squeal has been developed. In addition, a side wood embedded with a pure copper plate is installed in a floating manner, making the structure extremely resistant to vibration.
Pure copper oval insulator made of genuine leather is used for the insulator, which exhibits excellent vibration damping characteristics.

An α -X balanced power supply is used for the power supply.
The output stage is a balanced closed type, the first stage is an upper symmetric balanced constant current type power supply, and the secondary side of the transformer is a separate winding. The closed loop configuration is completely independent from the ground.

The key parts used to determine sound quality are non-magnetic, low impedance, and anti-vibration measures. For the transmission path of music signals, we use gold plated lead capacitors, film capacitors, resistors, and other top-of-the-line capacitors developed in the SANSUI VINTAGE series.
In addition, the speaker terminal uses OFC alloy 24-carat hardened gold plated terminal made by WBT of Germany with low signal loss, and it is also compatible with banana plug.
In addition, the volume knob is made of solid machined aluminum.

The signal connected to the direct input of the Route 3 is sent to the power amplifier section without passing through the preamplifier section.
It also has a balanced input terminal.

Equipped with a phono equalizer compatible with both MC and MM cartridges.

Both Bass and Treble enable stepless tone adjustment within ± 6.0 dB.

Equipped with 6-row detent volume.

Type Integrated amplifier
Power Amplifier Unit
Effective output (10 Hz to 20 kHz
Simultaneous operation of both channels) 190W + 190W (6 Ω) 160W + 160W (8 Ω)
Total harmonic distortion factor (at effective output) 0.003% or Less (8 Ω)
Cross modulation distortion factor 0.003% or Less (8 Ω)
Damping factor 150 (8 Ω)
Frequency Response (1W) DC ~ 300 khz + 0 -3dB
Input Sensitivity / Impedance 1V/10k Ω (1 kHz)
Signal-to-noise ratio (A network) 120 dB or more
Dynamic Power 580W (2 Ω)
390W (4 Ω)
310W (6 Ω)
TIM (SAWTOOTH) Measurement limit value or less
Slew rate 200 V / μ sec
Rise time 0.5 μ sec
Preamplifier Section
Input Sensitivity / Impedance
(1kHz) Phono MM : 2.5mV/47k Ω
Phono MC : 300 μ V/100 Ω
CD, Tuner, Line, MD/Tape1, Tape2 : 150mV/20k Ω
Phono maximum allowable input MM(THD 0.01%):210mV
MC(THD 0.1%):21mV
Frequency Response (1W) Phono MM : 20 Hz to 20 kHz ± 0.2 dB
CD, Tuner, Line, MD/Tape-1, Tape-2 : DC ~ 300 khz + 0 -3dB
Signal-to-noise ratio (A network) Phono MM : 90 dB or more
Phono MC : 75 dB or more
CD, Tuner, Line, MD/Tape-1, Tape2 : 110 dB or more
Tone control Maximum variation of Bass : ± 6 dB (50 Hz)
Maximum variation of Treble : ± 6 dB (15 kHz)
Subsonic filter 16 Hz (-3dB), 6dB/oct.
Loudness +4dB(50Hz)
+3dB(10kHz)

Rated power consumption 400W
External dimensions Width 462x Height 165x Depth 448 mm
Weight 33.0kg