Accuphase T-107
¥ 99,800 (released in July 1985)
Commentary
A synthesizer FM stereo tuner developed by putting in various technologies such as the latest PLL electronic tuning circuit and original DGL detector which applied the delay time of high-speed logic IC.
The tuning for channel selection can be adjusted to the desired signal with ± 0.002% accuracy by the crystal oscillator. There is almost no deviation due to time or temperature change, and it is locked to the sky with minimum distortion and maximum sensitivity.
The digital frequency display uses a static method that does not generate noise.
12-station memory tuning and automatic sweep tuning are available.
Memory allows you to store up to 12 FM stations of your choice. If you press the Manual button, you can use the Tune button to select the desired frequency.
Manual tuning is one step tuning with one touch. The tuning frequency can be changed at high speed if you keep pressing the button. If you press the Auto button, the tuning button automatically stops at the adjacent station.
The front end section is double-tuned between the input and amplifier stages, greatly improving interference (RF intermodulation) caused by large input interference waves.
By combining a newly developed DGL detector with a specially selected group-delay flat IF filter, we have obtained excellent characteristics of stable and undistorted capture ratio.
The DGL detection method focuses on the delay time of the output of a high-speed logic IC. Nineteen of these are connected in series. The phase angle is delayed by 114 degrees so that distortion is minimized and S/N is optimized. The delay signal and input signal are added to an exclusive OR circuit. The potential between the two signals is selected to open and close the circuit. The degree of density of the signal wave generated by modulation is digitally detected and an audio signal is extracted. The linear range of the delay circuit is extremely wide (± 5 MHz). Moreover, since it is a non-adjustable circuit, stable and excellent linear differential gain characteristics can be obtained.
In addition, two sets of IF filters, Normal and Narrow, are installed. When adjacent interference is severe, switching to Narrow enables sharp reception with a high degree of selectivity.
The internal oscillation circuit is locked (fixed) by the PLL circuit using the synchronizing pilot signal included in the input signal of the stereo demodulation section, and an accurate 38 kHz switching signal is obtained.
The T-107 employs a new method that combines the internal oscillation circuit of the PLL with a ceramic resonator and a variable positive and negative reactance circuit that can be controlled by the control voltage. As a result, accurate switching signals can be obtained in a narrower lock frequency range than the conventional one. As a result, the stereo demodulation circuit can be made without adjustment and initial characteristics can be maintained for a long time. In addition, there is almost no change in separation due to changes in temperature and line voltage, etc., and the lock frequency range is much narrower than the conventional one, so that beat distortion at high frequencies is reduced.
The meter can check input signal level and input signal level and multi-a changeover switch.
When the input signal level is on the dBf direct reading scale, and when the indicator of the multi-path meter is within the clear mark range, it indicates that high-quality radio waves are being received with minimum multi-path.
It is equipped with a noise filter to reduce noise in stereo stations with weak radio waves, a music switch to remove noise between stations, and an output level control to adjust the volume level to other program sources.
We have a champagne gold T 107 and a black T 107 b front panel.
The cabinet with natural rosewood finish was sold separately.
Model Rating
Type | Synthesizer FM tuner | ||||||||||||
MonAural Characteristics | |||||||||||||
Receiving frequency | 76.0 mhz to 90.0 mhz | ||||||||||||
Practical sensitivity | 11dBf(IHF) | ||||||||||||
S/N 50 dB sensitivity | 17dBf(IHF) | ||||||||||||
Standing-wave ratio | 1.5 | ||||||||||||
S/N (80 dBf input, A-correction) | 90dB | ||||||||||||
Total harmonic distortion factor (80 dBf input ± 75 kHz shift, Normal) |
20Hz:0.04% 1kHz:0.04% 10kHz:0.04% |
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IM distortion factor | 0.01% (80 dBf input, ± 75 kHz shift) | ||||||||||||
Frequency characteristic | 10 Hz ~ 16000 Hz + 0 -1.0 dB | ||||||||||||
Two signal selectivity (IHF) |
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Capture ratio | 1.5dB | ||||||||||||
RF intermodulation | 80dB | ||||||||||||
Spurious interference ratio | 100dB | ||||||||||||
Image ratio | 120dB | ||||||||||||
AM suppression ratio (65 dBf input) | 80dB | ||||||||||||
Subcarrier suppression ratio | 70dB | ||||||||||||
SCA interference ratio | 80dB | ||||||||||||
Output voltage (± 75 kHz deviation) | 1.0V | ||||||||||||
Stereo Characteristics | |||||||||||||
Sensitivity (IHF) | S/N 40dB:29dBf S/N 50dB:37dBf |
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S/N (80 dBf input, A-correction) | 85dB | ||||||||||||
Total harmonic distortion factor (80 dBf input ± 75 kHz shift, Normal) |
20Hz:0.04% 1kHz:0.04% 10kHz:0.08% |
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IM distortion factor | 0.03% (80 dBf input, ± 75 kHz shift) | ||||||||||||
Frequency characteristic | 10 Hz ~ 16000 Hz + 0 -1.0 dB | ||||||||||||
Stereo separation factor | 100Hz:50dB 1kHz:50dB 10kHz:40dB |
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Stereo switching input voltage | 20dBf | ||||||||||||
<General> | |||||||||||||
Antenna | 75 Ω unbalanced (with 300 Ω balanced converter) | ||||||||||||
Tuning system | Quartz synthesizer method 12-station random memory tuning | ||||||||||||
Detection system | DGL method | ||||||||||||
Output impedance | Fixed Output : 200 Ω Variable Output : 1.25k Ω (maximum) |
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Meter | Signal strength, multi-path switching | ||||||||||||
Semiconductor used | Transistor : 16 FET : 2 IC : 22 Diode : 59 LED : 18 pcs |
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Pwer | 100 VAC, 50Hz/60Hz | ||||||||||||
Power consumption | 12W | ||||||||||||
External dimensions | Body : Width 445x Height 107x Depth 330 mm A-11 : Width 463x Height 131x Depth 338 mm |
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Weight | 5.8kg | ||||||||||||
Sold Separately | Wood Cabinet A-11 (¥ 16,000) |