Technics SU-A707
¥ 54,800 (released in 1999)
Commentary
Integrated amplifier with VGCA for low noise
The amplifier circuit uses a unique low-noise amplifier VGCA (Variable Gain Control Amplifier).
In this circuit, the conventional amplifier configuration that narrows down the signal using the input volume and then amplifies the signal is eliminated. By changing the gain of the amplifier section itself, the amplifier is provided with a gain as much as necessary for amplification, and operates as a buffer amplifier with a gain lower than that. Volume control is performed by the volume linked after the amplifier, so that clearer sound can be played back at the normally used volume position.
It is equipped with MOS ClassAA circuit which adopts MOS FET as amplifying device based on ClassAA circuit.
The ClassAA circuit uses separate amplifiers for voltage amplification and current supply to achieve high power and complete class A voltage control.
The SU-A808 has a MOS ClassAA circuit equipped with a MOS FET amplifier with extremely high input impedance and excellent linearity at the final stage of controlling the outputs of a pure class A voltage control amplifier. In addition, the final stage of the current supply amplifier employs a bipolar transistor, which has a reputation for low-loss and high-power operation. The class AA Bridge effect maximizes the advantages of each amplifier, enabling compatibility with digital formats such as DVD audio.
The power transformer uses an R-core power transformer with a circular core cross-sectional shape. Since the magnetic flux is uniform and there is no junction in the core, leakage magnetic flux is extremely small and noise generation due to magnetic field is suppressed.
The electrolytic capacitor uses a bamboo / fiber mixed separator to achieve sound quality with less unwanted incidental sounds.
Uses gold-plated RCA terminal.
Equipped with a speaker terminal for banana plug.
System remote control is included.
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Model Rating
| Type | Integrated amplifier |
| Rated output | 50W + 50W (6 ohm, 20 Hz-20 kHz, 0.03%) 40W + 40W (8 ω, 20 Hz-20 kHz, 0.03%) |
| Total harmonic distortion factor | 0.03% (20 Hz to 20 kHz, rated output -3dB, 8 Ω, sum up to 10th harmonic) |
| Damping factor | 60 (8 Ω) |
| Load impedance | A or B : 4 Ω ~ 16 Ω A + B : 8 Ω ~ 16 Ω |
| Frequency characteristic | Tuner, CD, DVD, Aux, Tape1, Tape2/MD : 3 Hz to 100 kHz + 0 -3dB 20 Hz ~ 20 kHz + 0 -0.3 dB |
| Input Sensitivity / Impedance | Tuner, CD, DVD, Aux, Tape1, Tape2/MD : 150mV/22k Ω Phono MM : 2.5mV/47k Ω |
| Signal-to-noise ratio | 98 dB (JEITA) for Tuner, CDs, DVDs, Aux, Tape1, Tape2 / MDs 114 dB (S = 2 V rated output IHF'A) Phono MM:80dB(JEITA) 76dB(IHF'66) |
| Rated output voltage | Tape1, Tape2/MD Rec out : 150 mv |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 130W |
| External dimensions | Width 430x Height 136x Depth 368 mm |
| Weight | 7.4kg |
| Attachment | System remote control |