Accuphase T-107

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%
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)	Disturbance wave Normal Narrow 400kHz 70dB 100dB 300kHz 30dB 80dB 200kHz 8dB 30dB
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
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%
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
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)
Meter	Signal strength, multi-path switching
Semiconductor used	Transistor : 16 FET : 2 IC : 22 Diode : 59 LED : 18 pcs
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
Weight	5.8kg
Sold Separately	Wood Cabinet A-11 (¥ 16,000)