Audio Database

AU-alpha 607 NRAII

Improved model of AU - α 607 nra.

In order to eliminate the interference between the power windings in the transformer, an EI core transformer dedicated for the speaker drive is mounted on the final stage in a left and right independent power supply system, and a toroidal transformer is mounted on the power supply of the pre-drive stage so that the power supply to the final stage is independent.
In addition, a ripple filter circuit is adopted for the power supply of the predrive stage to provide a more stable power supply.
The toroidal transformer is completely shielded by pure copper material, Teflon sheet and special rubber, and it is mounted floating on the back of the front panel.

Uses SANSUI's original Ultimate α -X balance circuit.
By increasing the current margin of the driver stage to twice that of the conventional one and performing A-class operation, an excellent operating environment is realized in the transmission and amplification process from the input to the output of the first stage, driver stage and final stage.
The balance amplifier has a balanced configuration that does not depend on the ground circuit at all stages. It is a push-pull system in which a total of four amplifiers drive the speaker under the same condition with dedicated amplifiers placed on both + - sides of the L/R. Therefore, unlike conventional ground amplifiers, the sound quality is not affected by hum and noise components flowing through the ground, and the distortion mechanism caused by the speaker drive is eliminated and the sound quality is improved.

The pre-drive stage is equipped with a NEW diamond differential circuit that can take out + - output without phase inversion.
As a result, it has an excellent response to an input signal that changes instantaneously, and can supply a stable large current while suppressing the occurrence of TIM distortion to a very low level.

NM-LAPT (Non-magnetic Linear Amplification Power Transistor) is used for power devices.

The transformer and electrolytic capacitor are placed in the center of the chassis, and each L/R power unit is laid out symmetrically in twin monaural construction.
This prevents L/R interference and controls the vibration generated in the power supply system and vibration system from the structural aspect.

Uses NEW α -X balanced power supply which is further advanced by 2-transformer power supply circuit.
The final stage is left and right independently balanced closed type and the pre-drive stage is vertically symmetric balanced low-current power supply. In addition, the pre-drive stage and final stage power supply itself are completely independent closed loop configuration separated from the transformer.
In addition, the electrolytic capacitor of the power supply for the final stage uses an original block capacitor with a low-power tone foil, separator and plain foil.

Enhanced Twin Monaural construction, Integrated Mechanical Feedback and Mechanical Floating System for Power Transformer
The transformer is installed in a state of flow from the chassis, and interference to sound quality caused by vibration of the power supply system is blocked structurally.

In order to suppress the generation of vibration and resonance of the radiator to which the power transistor is attached, the radiator of new shape is adopted.

It uses an elliptical insulator with special material and structure.

A 6-row detent volume is used.

Uses a power cord with polarity display.

Model Rating
Type Integrated amplifier
Power Amplifier Unit
Effective output (10 Hz to 20 kHz
Simultaneous operation of both channels)
100W + 100W (6 Ω)
80W + 80W (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 310W (2 Ω)
210W (4 Ω)
150W (6 Ω)
TIM (SAWTOOTH) Measurement limit value or less
Slew rate 150 V / μ sec
Rise time 0.6 μ sec
Preamplifier Section
Input Sensitivity / Impedance
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 : 88 dB or more
Phono MC : 70 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 +6dB(50Hz)
Rated power consumption 230W
External dimensions Width 432x Height 165x Depth 450 mm
Weight 19.0kg