What is stereo?




There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.




H.H. Scott '59





Sansui TU-9900

Professional class tuner for superior stereo receeption under any kind of broadcast conditions.
The   elegance of these tuners speaks for itself because they are deigned to complement the amplifiers you choose. Sansui's indepth research contributes a lot and has helped keep phase distortion down and FM selectivity high, for all of the tuners in the range. The control this tuner gives over an incoming signal puts it into a class way above that of an ordinary FM stereo receiver. With the TU-9900it's very much like having a private line between the tuner and the FM stereo broadcasting studio. The TU-9900 is the ultimate in tuner sophistication. But the same Sansui thought goes into all of the Tuners. This tuner not only look good. Slanted tuning dials, separate signal/tune meters, smooth dial mechanisms and many other convenince features make them a pleasure to use.

Dependable Plus-Minus Power Supply
Musical reproduction from broadcast sources depends heavily on correct and accurate power supply circuitry. The TU-9900 'finst of the Sansui TU Series' incorporates an elaborate feedback type stabilized power supply section for this very reason. It is of the plus-minus dual supply type to guarantee ideal circuit performance at all times.
Superlow Distortion, 0,06%
A wide-band ratio detector and a PLL circuit in the FM multiplex demodulator are employed for lower phase deviation. The TU-9900thus boasts aa very low distortion figure of 0,06% (mono) and 0,08% (stereo) in FM operation to bring its performance up to the quality required by the very best amplifier components.
Selectable FM IF Bandwidth
To enhance both the tonal quality and the reception ability of the TU-9900, Sansui has provided a switch to select either a Wide or Narrow FM IF bandwidth. In the former, two 6-pole LC block filters are put on line to improve the sound quality; in the latter, a narrow-band ceramic filter is added for more effective rejection of adjacent signals.
Automatic Noise Canceller
When receiving weak (or remote) stations, this circuit automatically blends the left and right signals in optimum proportion to the strength of an incoming broadcast to deliver the same noise-free reception of any station regardless of its strength.

High-Performance FM Front-End
The TU-9900 features a sensitivity of 1,5 µV (IHF) thanks to its linear-frequency 5-gang variable capacitor and the three dual-gated MOS FETs and a transitor employed in the high-performance FM front-end.
Quality AM Reception
AM broadcast are received cleanly and quietly with the lowest noise or interference possible thanks to the use of a double-tuned circuit and a dual-element, dual-coil ceramic filter in the AM section.
Positive Action Tuning
The feel and accuracy of the special tuning mechanism in the TU-9900 will be appreciated for years of hard and frequent use. It features an oversized tuning knob a special tension mechanism, and a heavyweight, high-inertia sintered iron flywheel.
Special Features for Tape Recording
Tape buffs will appreciate these three special features:
1.A built-in recording test signal generator is provided to facilitate pre-recording calibration of optimum recording levels.
2.A low-pass filter is included to prevent the carrier frequencies of FM broadcasts from interacting with the bias frequencies of decks in use, thus avoiding the annoying "beat" noise otherwise heard. The filter can be defeated by a front panel switch when not recording.

Other Important Features:
The TU-9900 has an FM Antenna Attenuator Switch to cut down the strength of excessive incoming signals; a Multi-Path Detection circuit to help align antennas, highly accurate Twin Tuning Meters, FM Muting Switch, Dolby FM output terminals, and an Output Level Control.

Specifications:
FM Section
Tuning Range:  88 - 108 MHz
Sensitivity:  1,5 µV (IHF); 0,9 µV (DIN)[1 kHz, mod.30%,S/N26 dB]
Max. Input Capability:  more than 130 dB
Quieting Slope:
Mono Wide :  37 dB 1,5 µV, 51 dB 3 µV
Narrow :  37 dB 1,5 µV, 51 dB 3 µV
Stereo Wide :  39 dB 10 µV, 53 dB 50 µV
Narrow :  40 dB 10 µV, 54 dB 50 µV
Total Harmonic Distortion
Mono Wide :  less than 0,06% (at 1 kHz); less than 0,06% (at 50 Hz); less than 0,08% (at 10 kHz)
Narrow :  less than 0,05% (at 1 kHz); less than 0,05% (at 50 Hz); less than 0,08% (at 10 kHz)
Stereo Wide :  less than 0,08% (at 1 kHz); less than 0,1% (at 50 Hz); less than 0,15% (at 10 kHz)
Narrow :  less than 0,8% (at 1 kHz); less tha 0,8% (at 50 Hz); less than 1,2% (at 10 kHz)
Signal-to-Noise Ratio
Mono :  better than 80 dB
Stereo :  better than 76 dB
Selectivity
Wide :  better than 55 dB (at 400 kHz); better than 22 dB (at 300 kHz); better than 5 dB (at 200 kHz)
Narrow :  better than 90 dB (at 400 kHz); better than 60 dB (at 300 kHz); better than 20 dB (at 200 kHz)
Capture Ratio:
Wide :  less than 1,0 dB
Narrow :  less than 3,0 dB
AM Suppression:  better than 58 dB
Image Frequency Rejection:  better than 100 dB at 98 MHz
IF Rejection:  better than 110 dB at 98 MHz
Spurious Response Rejection:  better than 110 dB at 98 MHz
Spurious Radiation:  less than 34 dB
Stereo Separation: 
Better than 50 dB at 1 kHz (30 dB at narrow)
Better than 40 dB at 50 Hz (30 dB at narrow)
Better than 40 dB at 10 kHz (30 dB at narrow)
Frequency Response:  30 to 15,000 Hz, +0,5 -0,8 dB
Antenna Impedance; 
Balanced :  300 Ω
Unbalanced : 75 Ω
FM Antenna Attenuator:  -30 dB
AM Section
Tuning Range:  535 - 1605 kHz
Sensitivity (Bar Antenna):  45 dB/m at 1,000 kHz
Selectivity:  better than 70 dB at 1,000 kHz (±10 dB)
Image Rejection:  better than 100 dB/m at 1,000 kHz
IF Rejection:  better than 100 dB/m at 1,000 kHz
Total Harmonic Distortion:  less than 1% at 80% Modulation 100 dB/m
Semiconductors:  39 Transistors; 3 FETs, 7 Ics, 39 Diodes, 1 Zener Dioda; 5 LEDs
Power Requirements:  100,120, 220, 240 V, 50/60 Hz
Power Consumption:  20 watts rated
Dimensions (W x H x D):  460 x 160 x 310 mm (18-1/8" x 6-5/16" x 12-1/4")
Weight: 
Net :  9,6kg (21,2 lbs)
Packed :  11,3 kg (24,9 lbs)

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