SANSUI AU - α 507 nra
¥ 93,000 (released in 1998)
Commentary
Pre-main amplifier with Ultimate α -X balance circuit.
The Ultimate α -X balance circuit achieves an excellent operating environment in the transmission and amplification process from the input to the output of the initial stage, driver stage and final stage by raising the current margin of the driver stage to twice that of the conventional one and operating it in A-class operation.
The driver stage employs a NEW diamond differential circuit that can take out + - output without phase inversion. This has excellent current supply capability even for instantaneous input signals and suppresses TIM distortion, which is harmful to the sense of hearing.
A total of four dedicated amplifiers are arranged on the + and - sides of L and R of the output stage, and a NM-LAPT single push-pull system is adopted in which the speakers are dynamically driven from both + and - sides under the same conditions.
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.
In order to minimize the generation of vibration, a new shape radiator is adopted.
By adopting an elliptical insulator, vibration is dispersed effectively.
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) |
80W + 80W (6 Ω) 60W + 60W (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 |
Signal-to-noise ratio (A network) | 120 dB or more |
Dynamic Power | 280W (2 Ω) 180W (4 Ω) 130W (6 Ω) |
TIM (SAWTOOTH) | Measurement limit value or less |
Slew rate | 180 V / μ sec |
Rise time | 0.6 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 : 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 | +8dB(50Hz) +4dB(10kHz) |
<General> | |
Rated power consumption | 160W |
External dimensions | Width 432x Height 165x Depth 450 mm |
Weight | 15.5kg |