SANSUI AU-70
¥ 42,000 (released in 1964)
Commentary
A pre-main amplifier released as a full-fledged stereo amplifier.
7189 is adopted for the output tube, AB1It operates in P. P. (fixed bias system).
In this class, a multiple feedback circuit (total NF 26 dB) was introduced for the first time in Japan to reduce distortion over all bands.
A 3-stage amplifier circuit is used for the control amplifier section, and all circuits are contained in an NF loop to suppress noise and distortion.
Sansui's original 4-transistor head amplifier with transistor circuit index S = 4 and transistor noise index NF = 2 dB is used.
In the tone control circuit, the bass and treble sections are separated for each channel.
In addition, since it is equipped with tone defeat (tone circuit cancellation device), flat characteristics without waviness or loss of gain can be obtained.
Equipped with a blend circuit that can control the spread.
As you turn the knob to the right, you can freely adjust the sound spread from mono to stereo.
Equipped with center channel output terminal, 3-D stereo reproduction is possible.
Equipped with an output level meter that can be switched to 3 levels of 5W, 10W, and 15W.
Model Rating
Type | Tube type pre-main amplifier | ||
Power Amplifier Unit | |||
Maximum power output | 25W-25W | ||
Harmonic distortion factor (20W) | 0.15% or Less (1 kHz) 0.95% or Less (36 Hz) |
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Cross modulation distortion factor | 0.85% or Less (15W, 50 Hz + 5 kHz) | ||
Frequency characteristic | 10 Hz to 80 kHz ± 1 dB or less | ||
Output impedance | 8 Ω, 16 Ω | ||
Preamplifier Section | |||
Gain at 20W output | Phono(MAG):81dB/1.6mV Phono(X-TAL):54dB/36mV Tape:86dB/0.9mV Mic:86dB/0.9mV AUX(Tapemon):51dB/50mV Tuner:51dB/50mV |
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Tone control | CR Type 50 Hz : + 11 dB to -15dB 10 kHz : + 12 dB to -13dB |
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Equalizer | NF Type Tape(BTS) Phono(RIAA) |
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<General> | |||
Accessory circuit | Presence control Turnover : 150 Hz Low Filter : 50 Hz, -12.5 dB High Filter : 10 kHz, -13.5 dB Loudness control Tone defeat Tape monitor Headphone jack Tape recorder recording / re-connector Terminal for center channel amplifier Level meter (3-step switching of 5W, 10W, 25W) Blend control |
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Semiconductor used |
Germanium Diode (OA-81) : 2 Pieces Silicon Diode (SD-1A) : 2 pieces Selenium Rectifier (TC. 0.2P11/3) : 1 Piece |
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Pwer | 100 VAC, 117 V, 240 V, 50Hz/60Hz | ||
Power consumption | 118VA | ||
External dimensions | Width 405x Height 142x Depth 320 mm | ||
Weight | 13.7kg |