SANSUI AU-D707G Extra
¥ 118,000 (released in 1983)
Commentary
An integrated amplifier based on the AU-D707F Extra with improvements such as ground floating circuits.
A ground floating circuit is installed to prevent the influence of the ground circuit of the input, output and power supply.
In this circuit, the output amplifier, load (speaker), and power supply are completely closed loop to eliminate the influence of the speaker. The power supply section is also floating. In addition, the power supply section has a dual bridge configuration with independent power transformer windings to reduce IHM distortion that is harmful to sound quality.
The power supply unit has been strengthened by installing a large toroidal transformer in addition to the left and right independent power supply configuration.
The electrolytic capacitor is a pure focus capacitor with excellent follow-up performance against transient charge and discharge.
Linear step MC transformer is mounted to support MC cartridge.
This transformer was installed in the AU-D907F Extra. By using SANSUI's original technology, the start-up characteristic of conventional step-up transformers is improved and an excellent S / N ratio is obtained.
In addition, to take advantage of the advantages of the linear step MC transformer, the optimum load is installed. Moreover, in order to be compatible with all types of MC cartridges, a two stage impedance switching system of Low and High is adopted.
The power amplifier is equipped with a diamond differential circuit in the pre-drive stage and a super FF in the power stage.
The Super FF is a circuit that combines the advantages of NFB and feed-forward. It uses an error collection amplifier to create a signal with the opposite phase to the distortion that cannot be canceled by NFB, and cancels the distortion at the output.
The equalizer is equipped with a high-precision equalizer that covers a wide range of RIAA deviation from 20 hz to 300 khz ± 0.2 db. The power supply is equipped with a linear servo regulator that provides a clean and stable power supply.
In order to eliminate magnetic distortion, which is a modulation effect of signals due to magnetic fields, we use copper-plated chassis and NM (non-magnetic) elements, as well as construction that is less affected by electromagnetic wave flux.
Input terminals for DA and PCM are mounted.
Power cord with polarity display is used.
Two systems can be connected by twin relay speaker switch.
Equipped with a subsonic filter and a supersonic filter.
Gold plated terminals are used for the four terminals.
Equipped with two independent source recording selectors and two circuit tape monitoring / copying functions.
There are 2 color variations of black and silver.
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Model Rating
| Type | Integrated DC amplifier |
| Power Amplifier Section (Ground Floating, Super Feedforward & DD/DC System) | |
| Effective power | 110W + 110W (8 ohm, 10 hz to 20 khz, THD 0.003%) 110W + 110W (8 ohm, 1 khz, 0.002% THD) |
| Total harmonic distortion factor (10 Hz to 20 kHz at effective output) | 0.003% or Less (8 Ω) |
| Intermodulation Distortion Factor (60 Hz : 7 kHz = 4 : 1, SMPTE) | 0.003% or Less (8 Ω) |
| Output Bandwidth (IHF, both channel operation, THD 0.02%) | 5 Hz ~ 80 kHz (8 Ω) |
| Damping factor (new IHF, 20 Hz to 20 kHz) | 100 (8 Ω) |
| Frequency Response (1W) | DC ~ 300 khz + 0 -3dB |
| Envelope distortion | Below the measurement limit |
| TIM Strain (Sawtooth method) | Below the measurement limit |
| Slew rate | ± 200 v / μ sec (8 Ω) |
| Rise time | 0.5 μ sec |
| <Equalizer amplifier (Hi-Precision DC servo equalizer)> | |
| Input Sensitivity / Input Impedance (1 kHz) | Phono1, 2 mm : 2.5mV/47k Ω Phono1, 2 mc (Low/High) : 100 μ V/300 μ V (100 Ω) Tuner, Aux/DA, Tape/PCM play1, 2 : 250mV/27k Ω |
| Phono maximum allowable input (1 kHz, THD 0.01%) | MM:200mV MC : 25 mV (low), TRANS system |
| Output Level / Impedance (1 kHz) | Tape rec (PIN) : 250 mv (47k Ω) / 600 Ω |
| Total harmonic distortion factor (20 Hz to 20 kHz at 5 V output) | Phono1, 2 MM : not more than 0.005% Phono1, 2 mc : Transformer system |
| RIAA Deviation (MM, Rec out) | 20 Hz to 300 kHz ± 0.2 dB |
| Signal-to-noise ratio (A network, short circuit) | Phono1, 2 mm : 90 dB or more Phono1, 2 mc : 80 dB or more (70 μ V) Tuner, Aux/DA, Tape/PCM play1, 2 : 110 dB or more |
| Phono input equivalent noise (A network, short circuit) |
Phono1, 2 mm : -142dBV Phono1, 2 mc : -160dBV |
| Channel Separation (1 kHz) | Phono1, 2 mm : 60 dB or more Phono1, 2 mc : 50 dB or more Tuner, Aux, Tape play : 80 dB or more |
| Tone control | Bass : ± 10 dB (50 Hz) Treble : ± 10 dB (10 kHz) |
| Tone selector | Bass : 150 Hz, 300 Hz Treble : 3 kHz, 6 kHz |
| Filter | Low : 16 Hz (-3dB, 6dB/oct.) High : 20 kHz (-3dB, 6dB/oct.) |
| Audio Muting | -20dB |
| <General> | |
| Rated power consumption (Electrical Appliance and Material Control Law) | 270W |
| External dimensions | Width 460x Height 160x Depth 404 mm |
| Weight | 15.0kg |