Audio Database

AU - α 607 nra

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

The Ultimate α -X balanced circuit achieves an ideal operating environment for audio amplifiers in all stages of transmission and amplification from input to output by doubling the current margin of the driver stage to A-class operation. In addition, the driver stage is equipped with a NEW diamond differential circuit that can take out + - output without phase inversion. This provides excellent current supply capability for instantaneous input signals and suppresses TIM distortion.
In addition, a total of four dedicated amplifiers are arranged on the + and - sides of the L/R of the output stage, and the NM-LAPT single push-pull system is adopted which dynamically drives the speakers from both ± and ± under the same conditions.

The power supply section uses the NEW α -X balanced power supply system.
The output stage is a balanced closed type power supply, the first stage is a vertically symmetrical balanced constant-current power supply, and the secondary side of the transformer is also a separate winding. This realizes a closed-loop configuration that is completely independent of the earth. This prevents unbalanced power supply currents that adversely affect sound quality.
We also use custom parts such as low-magnification electrolytic capacitors for power supplies that use foil for high sound quality.

The chassis structure uses twin monaural construction and balanced mechanical feedback to reduce mutual interference.
In addition, the AU - α 607 nra eliminates mechanical interference by floating the power transformer, which is the largest source of vibration, from the chassis so that the power system vibration is not transmitted to the chassis.
In addition, an elliptical insulator is used.

In order to suppress the vibration of the heat sink, we have developed a radiator with a new shape that minimizes the generation of vibration. This effectively disperses the resonance effect and suppresses interference between the vibration of the power supply system and music signals.

Equipped with a power amp direct input function for CD and Line.

A 6-row detent volume is used.

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 250W (2 Ω)
200W (4 Ω)
140W (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
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 ~ 200 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 220W
External dimensions Width 432x Height 165x Depth 450 mm
Weight 18.0kg