SANSUI TU-S707X Decade
¥ 54,800 (released in 1985)
Commentary
FM/AM tuner equipped with SLDDII.
It is equipped with SLDDII, a digital demodulation system unique to SANSUI.
In this circuit, switching carriers themselves are made closer to sine waves, which do not have demodulation capability for unnecessary high frequencies. This eliminates anti-noise filters and correction circuits, which degrade sound quality, and improves Birdie and sound quality.
Front end equivalent to 5 train is adopted.
This circuit uses a twin varicap diode to improve the interference rejection capability at the inlet and to prevent tuning deviation and distortion. In addition, by using a dual-gate MOS FET in the RF stage and mixer section, linearity, SN ratio and distortion factor are improved, and dynamic range at strong input is ensured.
Equipped with an IF band switching function.
Conventional tuners have a problem that they are susceptible to interference from neighboring stations when the tuner is wide. However, in the TU-S707X Decade, this problem is solved by the SLDDII. Since no harmonics are generated in the demodulation process, no noise is generated by neighboring stations even when the tuner is wide.
Narrow position is used as a countermeasure against interference in a limited area.
In order to eliminate noise from the FM antenna and speaker cable, both FM and AM antennas are balanced by a floating circuit system with a separate GND.
This floating circuit system achieves a good signal-to-noise ratio in actual use by shutting out common-mode noise caused by the difference in ground potential between the system and the chassis.
Semiconductor ceramic capacitors are used in high-frequency circuits to achieve low distortion and high signal-to-noise ratio, while fast recovery diodes and high-performance capacitors are used in the power supply to improve sound quality.
The sound quality is improved by a static drive system in which the FL frequency tube is separated from the signal line.
Built-in preset memories are available for a total of 16 preset memories, 8 FM stations and 8 AM stations.
In addition, it is equipped with a preset scan function so that you can monitor the stored program sequentially for approximately 4 seconds.
Lithium memory backup with lithium batteries and high-capacity capacitors enables memory with a life of more than five years.
The AM tuner section is designed for higher SN.
Equipped with 400 Hz, 0.39 V REC calibration function.
The RF MODE, which prevents front-end saturation at large inputs, and the FM Noise Canceler are used to improve reception capability by optimally responding to local radio wave conditions.
Equipped with Last One Memory that automatically calls up the station when power is OFF.
Uses a power cord with polarity display.
Model Rating
| Type | FM/AM Tuner |
| FM Tuner Section | |
| Practical sensitivity (IHF) | Mono : 10.8 dB (old IHF : 0.95 μ V) |
| 50 dB sensitivity | mono:16.2dBf stereo:37.0dBf |
| Harmonic distortion factor (IHF, 80 dBf, wide, 1 kHz) | mono:0.0095% stereo:0.015% |
| SN ratio (85 dBf) | mono:94dB stereo:88dB |
| Frequency characteristic | 10 Hz to 15 kHz ± 0.5 dB |
| Capsule ratio | 0.8dB |
| Selectivity | narrow:60dB wide:26dB |
| Stereo separation | 65dB(1kHz) 50 dB (50 Hz to 10 kHz) |
| Image interference ratio | 100 dB or more |
| IF interference ratio | 110 dB or more |
| Spurious interference ratio | 110 dB or more |
| AM suppression ratio | 75 dB or more |
| Subcarrier suppression ratio | 70 dB or more |
| <AM Tuner Section> | |
| Practical sensitivity | 48dB/m (251 μ V/m) |
| Signal-to-noise ratio | 50dB |
| Selectivity | narrow:50dB wide:30dB |
| <General> | |
| Rated power consumption (Electrical Appliance and Material Control Law) | 11W |
| External dimensions | Width 466x Height 57x Depth 306 mm |
| Weight | 4.0kg |
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