SANSUI AU - α 607i

Commentary

Stereo pre-main amplifier with α -X balanced circuit.

The α -X balanced circuit uses an independent amplifier for both the + side and the - side of the signal to transmit and amplify it. Since it is separated from the ground, the effect of noise and distortion from the ground is prevented in principle.
In addition, the input stage of the power section is a differential balance input using a low-noise FET, and the common-mode rejection ratio CMRR (Common Mode Rejection Rato) between the + side and - side of the signal system is large, so that the circuit itself cancels common-mode noise and distortion.
In addition, while conventional amplifiers drive between the output of the amplifier and the ground, the α -X balanced circuit drives from both the + and - sides. This eliminates power supply noise and prevents IHM (Interface Hum Modulation) from occurring due to back electromotive force from the speakers.

The power supply section uses a unique balanced power source that is independent from the ground and closed loop.
The current is always equal between the + side and the - side, which prevents adverse effects on the signal due to unbalanced power supply and is also resistant to noise from the AC line and power supply fluctuations.
In addition to a large transformer with high capacity and excellent regulation, a gold supply capacitor with high charge / discharge speed and a fast recovery diode are used.

In addition to the master regulator, we have adopted a twin regulator system in which local regulators are placed on the phono equalizer board and preamplifier board.
The 2-stage regulator is resistant to fluctuations in power supply and load, enabling a stable and clean power supply.

Equipped with an active tone control that can also be lost.

board with excellent vibration damping characteristics is used for the board of the power section.

A solid and anti-flux chassis designed to eliminate vibration and noise interference is used. Each stage is completely separated and shielded by a separator, and five large insulators (CF5 insulators) with optimum load distribution are used to prevent external vibration.

A phono equalizer of FET configuration is used.

Equipped with a source direct function that passes accessory circuits of subsonic filter, muting and balance control and connects all input sources directly to the pre-drive stage.

Model Rating

Type	Α -X balanced integrated amplifier
Power Amplifier Unit
Rated output (10 Hz to 20 kHz, both channel drive)	105W + 105W (6 Ω) 90W + 90W (8 Ω)
Total harmonic distortion factor (at effective output)	0.003% or Less (8 Ω)
Cross modulation distortion factor (at effective output)	0.003% or Less (8 Ω)
Damping factor	150 (8 Ω)
TIM (SAWTOOTH)	Measurement limit value or less
Preamplifier Section
Input Sensitivity / Impedance (1kHz)	Phono MM : 2.5mV/47k Ω Phono MC : 300 μ V/100 Ω CD, Tuner, Line, Prossesor, Tape/DAT/Play1 ・ 2 ・ 3 : 150mV/47k Ω
Phono maximum allowable input	MM:210mV(THD 0.01%) MC:21mV(THD 0.1%)
Frequency characteristic	Phono MM : 20 Hz to 20 kHz ± 0.2 dB CD, Line, Tape/DAT/Play1 / 2 / 3 : 1 hz ~ 300 khz + 0 -3dB
Signal-to-noise ratio	Phono MM : 88 dB or more Phono MC : 70 dB or more Tuner, Line, CD, Tape/DAT/Play1 / 2 / 3 : 110 dB or more
Tone control	Maximum variation of Bass : ± 5 dB (50 Hz) Maximum variation of Treble : ± 5 dB (15 kHz)
Subsonic filter	16 Hz (-3dB), 6dB/oct.
Loudness	50Hz:+8dB 10kHz:+6dB
Audio Muting	-20dB
<General>
Rated power consumption	240W
External dimensions	Width 448x Height 160x Depth 441 mm
Weight	16.0kg