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Sansui TU-666 tuner
Nice tuner with good performance, made by Sansui in 1970.
Type: Mono/Stereo Tuner
Tuning Bands: FM, MW
Tuning Scale: Round Analogue
FM Tuning Range: 88 to 108 MHz
MW Tuning Range: 535 to 1605 kHz
Sensitivity: 2.0µV (FM), 20µV (MW)
Signal to Noise Ratio: 65dB (FM)
Distortion: 0.8% (FM)
Selectivity: 55dB (FM), 20dB (MW)
Semiconductors: transistor: 24, FET:1, IC:1, Diode: 19
Dimensions: 335x 127 x 276mm
Round scale ^
FM/AM round scale with tuning meter and stereo lamp, one colour: green.
Click here to download the TU-666 / AU-666 brochure in PDF format
Click here to download the TU-666 usermanual in PDF format (construction)
TU-666 with AU666 ^
Click here to download the TU-666 schematic in PDF format
Click here to download the TU-666 stereo decoder schematic in PDF format
There are transistors and one FET used and a lot of diodes: only 1 early IC.
Internal Sansui TU-666 ^
The build quality is excellent, although some
parts are not easely accessable,
like the FM front-end that is bigger than in the TU-555.
The FM front-end suffers in many TU-666 instability caused by bad soldering by Alps,
together with the instability of the power supply the tuner has sometimes problems with stable tuning
and tends to walk away from the tuned station, the S-meter is of average quality.
All electrolytic caps are out of specs after 50 years. Wiring is is much better and cleaner than the TU-555,
but still some wires are too long, a problem that many Sansui gear have from that time frame.
You may exchange all electrolytic
capacitors. You may add a resistor of 1 Ohms
@ 5 Watts in series with the bulbs of the
It lowers the heat dissipation of the bulbs and makes the light in the scale somewhat softer.
Bottom view ^
FM - IF section ^
AM section V
Audio Section & stereo-decoder ^
Power supply pcb ^
3 gang FM capacitor ^
Power supply Transformer ^
Wood top ^
The FM reception and sound of this tuner is very good, regarding the some 50 years of age: A real high-end product of its time.
TU-666 & AU-666 ^
© PE1MMK Hans Hilberink, last update: 15-09-2019.