SANSUI AU-666
¥ 52,800 (released in May 1970)
Commentary
This pre-main amplifier was created not only with sound quality, function and expandability, but also with a design that is full of functional beauty and is closely related to the speaker system.
The main amplifier section uses a 2-stage differential-amplifier circuit and PNP and NPN for the output-transistor. It is a perfect direct connection positive and negative power supplies without an output-capacitor. It is a complete complimentary service Darlington circuit system.
For this reason, uniform NF is applied from the DC range to the entire audio range, the damping factor and output characteristics are constant up to the ultra-low frequency range, the speaker's exposure in the ultra-low frequency range is sharply reduced, and the intermodulation distortion in the amplifier and speaker is reduced.
Since the distortion component is canceled by the combination of PNP and NPN, the distortion of the amplifier itself is kept low.
A specially selected low-noise silicon transistor is used in the preamp section to minimize the noise.
In order to avoid using an electrolytic capacitor with poor transmission characteristics due to large phase distortion for the coupling capacitor, we use a direct-coupled circuit as much as possible, make the capacitor higher, and use a Mylar capacitor.
In addition, a Mylar type is used in parallel in areas where electrolysis is absolutely necessary to improve high-frequency characteristics.
Equipped with triple tone control that can adjust Bass, Treble, and Midrange.
Since the left and right can be adjusted separately, more accurate program and room acoustic compensation is possible.
It is also possible to separate the preamp section and main amplifier section.
Equipped with two types of speaker outputs, A and B.
A dedicated transistor is used for temperature guarantee, and a differential amplifier stabilizing circuit is used for the 2-stage differential amplifier to further stabilize the differential amplifier.
In addition, it uses 6 short-cut fuses for perfect protection in case of emergency.
Separate ripple filter circuits are attached to the main amplifier's positive and negative power supplies and to the preamplifier power supply to stabilize the power supply.
Equipped with an NF type low filter, high filter, loudness control, tape monitor circuit, headphone jack, muting switch, microphone input jack, etc.
Model Rating
Stereo pre-main amplifier | |||||
Main Amplifier Section | |||||
Rated output |
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Total harmonic distortion factor | 0.5% or Less (Rated Output) | ||||
Intermodulation Distortion Factor (SMPTE, 60 hz : 7 khz = 4 : 1) | 0.5% or Less (Rated Output) | ||||
Power Band With (IHF) | 10 Hz ~ 40000 Hz (8 Ω) | ||||
Frequency characteristic | 10 Hz to 70000 Hz, ± 1 dB | ||||
Channel separation | 60 dB or More (1 kHz, Rated Output) | ||||
Hum and noise (IHF) | 100 dB or more | ||||
Input Sensitivity / Impedance | 1 V (Rated Output) / 50k Ω or More | ||||
Load impedance | 4 Ω ~ 16 Ω | ||||
Damping factor | 40 (8 Ω Load) | ||||
Preamplifier Section | |||||
Output voltage | Maximum power : 5 v Rated output : 1 V |
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Total harmonic distortion factor | 0.1% or Less (Rated Output Voltage) | ||||
Frequency characteristic | 20 Hz to 40000 Hz, ± 1 db | ||||
Channel separation | Phono1, 2 : 50 dB or more Tuner, AUX : 50 dB or higher |
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Hum and noise (IHF) | Phono1, 2 : 70 dB or more Tuner, AUX : 80 dB or higher |
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Input Sensitivity (1 kHz, Rated Output Voltage) / Impedance | Phono1, 2 : 2mV/50k Ω MIC : 3mV/50k Ω Tuner : 180mV/100k Ω AUX : 180mV/100k Ω Tape Play (Pin) : 180mV/100k Ω Tape Recorder (Din) : 180mV/100k Ω |
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Recorded output | Tape Rec(Pin):180mV Tape Recorder(Din):30mV |
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Equalizer | Phono : RIAA NF Type MIC : Flat NF Type |
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Controls | Bass : 30 Hz, ± 16 dB Midrange : 1500 Hz, ± 5 dB Treble : 15000 Hz, ± 15 dB |
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SWITCH | Low filter : 20 Hz, -10dB High filter : 20 kHz, -10dB |
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Muting | -20dB | ||||
<General> | |||||
Configuration | Transistor : 31 Diode : 5 |
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Power supply voltage | 100 V, 50Hz/60Hz | ||||
Power consumption | 240W | ||||
External dimensions | Width 415x Height 127x Depth 278 mm | ||||
Weight | 9.75kg |