SANSUI 771
¥ 89,900 (around 1972)
Commentary
This FM/AM stereo receiver combines pre-main and tuner into one by making use of Sansui's technology and experience.
Each part was examined and integrated into three printed circuit boards : main amplifier, tone control, and tuner.
In particular, the control section, which is an operation part, has an integrated structure in which volumes and switches are directly attached to the printed circuit board to eliminate failures such as poor contact, and each circuit is integrated as much as possible to improve reliability.
All stages of the power amplifier are directly connected with pure complimentary service system.
By removing the coupling capacitor between stages and supplying ± 2 power supply, harmful distortion is suppressed from ultra-low band to ultra-high band, and stable operation is obtained.
The equalizer amplifier uses a 2-stage direct-coupled NF type that provides excellent characteristics, and the maximum allowable input is large enough to accommodate records with a wide dynamic range.
The RIAA deviation is also corrected accurately by carefully selecting elements with high accuracy.
Equipped with a microphone circuit, a high-impedance microphone can be used.
When the microphone plug is inserted into the jack, the microphone amplifier is automatically activated and positioned at the center of the speaker.
The tone control is an NF type using a low-noise FET.
Both the high and low frequencies are Klix/Klukš top type and can be varied in 10 steps each.
The protective circuit is a combination of a relay and an electronic circuit to prevent pop noise when the power is turned on.
Aluminum die-cast is used for the frame of the tuning mechanism.
A large flywheel, a back tension spring system with tension in the dial thread, and an FM scale with equal spacing of 250 kHz enable smoother channel selection.
The FM front-end uses a dual-gate MOS FET and a precision four link varicon.
In addition, a double-tuned circuit is combined to enable stable reception with less distortion.
The FM IF section is composed of a 6-element ceramic filter and a differential amplifier 2-stage 2-IC, and has obtained good characteristics with little distortion.
A highly stable dedicated IC is used in the MPX section, which separates and demodulates FM signals to the left and right.
The AM tuner section has a Yaman type 2-element ceramic filter in the IF section.
In addition to the microphone, there are two tape monitor circuits. The tape monitor 2 can be used with a 4-channel adapter. There is also a DIN terminal.
The speaker outputs are Route 3 mounted and can be used with A/B/C/A + B/A + C.
It is equipped with a low filter that cuts rumble generated in the ultra-low range such as motor grounder, and a high filter that cuts harsh record and tape hissing generated in the high range.
It is equipped with an audio muting switch, which attenuates by -20dB when turned ON.
It is equipped with a loudness switch that adjusts the balance of sound by increasing the low and high sound at low volume.
Equipped with a Stereo-Mono changeover switch.
It has a built-in FM muting switch, which blocks out unpleasant FM-specific inter-station noise.
It is also possible to select stations with weak radio waves by switching the switch.
The AC auxiliary power outlet has two circuits.
Equipped with 2 large grounding terminals.
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Model Rating
| Type | FM/AM stereo receiver | ||||||
| Amplifier Unit | |||||||
| Rated output |
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| Total harmonic distortion factor (at rated output) | Not more than 0.5% | ||||||
| Intermodulation distortion factor (at rated output) | Not more than 0.5% | ||||||
| Power Band With (IHF) | 15 Hz ~ 40 kHz | ||||||
| Frequency characteristic | 15 Hz -30kHz + 1-2dB | ||||||
| RIAA deviation (30 Hz to 15 kHz) | ± 1.0 dB | ||||||
| Load impedance | 4 Ω ~ 16 Ω | ||||||
| Damping factor | 60 (8 Ω) | ||||||
| Hum and noise | Phono : 70 dB or more AUX : 80 dB or more |
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| Input Sensitivity / Impedance (1 kHz) | Phono : 2.5mV/50k Ω (total harmonic distortion rate 0.5% or less) MIC (mono) : 2.5mV/50k Ω AUX1, 2 : 100mV/50k Ω Tape Monitor1, 2 : 100mV/50k Ω |
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| Maximum allowable input | Phono:150mV | ||||||
| Output voltage | Tape Monitor Pin:100mV Tape Monitor Din:30mV |
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| Tone control | Bass : ± 12 dB (50 Hz) Treble : ± 12 dB (10 kHz) |
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| Low filter | -10dB (50 Hz, 6dB/oct.) | ||||||
| High filter | -10dB (10 kHz, 6dB/oct.) | ||||||
| Loudness | + 10 dB at 50 Hz, + 8 dB at 10 kHz | ||||||
| FM Tuner Section | |||||||
| Sensitivity (IHF) | 2.0 μ V | ||||||
| Total harmonic distortion factor | mono:0.4% stereo:0.6% |
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| Signal-to-noise ratio | 60 dB or more | ||||||
| Capture ratio | 2.0 dB or more | ||||||
| Image Rejection | 75 dB or More (83 MHz) | ||||||
| IF Rejection | 90 dB or more (83 MHz) | ||||||
| Spurious response rejection | 80 dB or More (83 MHz) | ||||||
| Stereo separation | 35 dB or More (400 Hz) | ||||||
| Frequency characteristic | 30 Hz to 12 kHz + 1 -3dB | ||||||
| <AM Tuner Section> | |||||||
| Sensitivity (bar antenna) | 50dB/m(1kHz) | ||||||
| Selectivity | 28 dB or More (1 kHz, ± 10 kHz) | ||||||
| Image View Rejection | 80dB/m or more (1 MHz) | ||||||
| IF Rejection | 80dB/m or more (1 MHz) | ||||||
| <General> | |||||||
| Rated power consumption | 100W (310 VA max) | ||||||
| External dimensions | Width 480x Height 135x Depth 300 mm | ||||||
| Weight | 12kg | ||||||