Description
The Sansui AU-7900 is an integrated stereo amplifier give a high power output of 80 Watts per channel of clean, undistorted music reproduction: so accurate it becomes difficult to distinguish from the original live performance.
Features include
NF-type phono equaliser: the deviation from the standard RIAA curve is only -± 0,3dB over the entire range. Superb preamp, superb powerful amplifier.
Tape play/dubbing switch, simultaneous connection of two stereo tape decks.
Triple Tone Control: bass, treble and midrange with selectable turnover frequencies.
Direct-coupled true complementary OCL output capacitor less.
Dual power supply, triple power-circuit protection.
Specifications
□Power output: 75 watts per channel into 8Ω (stereo)
□Frequency response: 5Hz to 40kHz
□Total harmonic distortion: 0.1%
□Damping factor: 80
□Signal to noise ratio: 90dB (line)
□Channel separation: 50dB (MM)
□Dimensions: 430 x 132 x 340mm
□Weight: 14.2kg
□Year: 1976
□General
An integrated amplifier that achieves ample power and low distortion through an original input / output terminal structure & design policy that emphasizes the power supply section.
□Circuit
The pure complementary circuit directly connected to all stages is adopted as a power amplifier part. The differential amplification which used the dual transistor is adopted as the first stage & the Darlington three-stage configuration with an active load is adopted as a drive stage. Further more, the power supply of the predrive stage is made into a separate circuit from the output stage. This has improved linearity & has suppressed the occurrence of non-linear distortion even when a transient signal is input.
□Characteristic Transistors
The parallel push-pull system is adopted as an output stage. In AU-7900, low distortion and large output are achieved by combining four power transistors with uniform characteristics per channel and improving the linearity of current characteristics.
□Equalizer
The equalizer circuit has adopted the NF type equalizer circuit which was composed of four low-noise transistors & the first stage input is a differential amplification with a good DC balance. Sufficient margin is secured by supplying ± 2 power supplies with a high voltage of 51Volt DC in total with good regulation. The CR element carefully selected is adopted as an equalizer element.
□Input Structure
The Phono1 input can switch the impedance in 3 steps. The input terminal part on the back has adopted the unique structure which attached the terminals upward. With this structure, it is not necessary to use a shielded wire from the input terminal to the selector, and it is possible to prevent deterioration of high frequency characteristics due to stray capacitance.
□PreAmplifier
The preamplifier section and the main amplifier section can be separated with the switch on the back panel.
□Low Noise Semiconductors
The low noise transistor and the high precision CR element are used in the tone control circuit. By making these parts and switches directly attached to one board, the lead wire and shielded wire are prevented from being routed. The circuit configuration has a differential amplification in the first stage, and is an NF type that ensures stable operation with ± 2 power supplies. More over, the detent type volume which has the same performance as an attenuator and less error is adopted as the variable resistor of the tone control of AU-7900.
Link
/ jn_electrics
#SansuiAU-7900 #AmplifierStereo #JNElectric
Негізгі бет Ғылым және технология Sansui AU-7900 is an integrated stereo amplifier giving a high power output of 160 Watts
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