¥ 72,500 (around 1971)
A newly designed stereo pre-main amplifier with performance and functions similar to the AU 999.
The main amplifier section is fully connected with a 2-stage differential-amplifier circuit and two positive and negative power supplies without capacitor, and adopts complimentary service Darlington circuit system.
As a result, uniform NFB is applied from the DC range to the entire audio range, the damping factor and output characteristics are constant up to the ultra-low range, and the speaker's blur in the ultra-low range is reduced, reducing intermodulation distortion.
The preamp section uses a PNP silicon transistor which has less noise than the NPN silicon transistor to reduce noise.
We use direct-coupled circuits as much as possible, minimize capacitors, increase circuit impedance where necessary, and use a Mylar type to reduce electric field capacitors as much as possible.
In addition, Mylar type capacitors are used in parallel for areas where electric field capacitors are absolutely necessary to improve high-frequency characteristics.
A dedicated transistor is used for temperature compensation, a differential amplifier stabilization circuit is used for the 2-stage differential amplifier to further stabilize the differential amplifier, and a protective circuit is used with 6 quick disconnect fuses.
When the power transistor is damaged, an abnormal voltage is generated and DC current does not flow to the speaker. A speaker protection circuit using SCR is installed to protect the speaker even in an emergency.
Includes Bass, Midrange and Treble T. T. C (Triple Tone Control).
This allows for more accurate program and room acoustic compensation.
The preamp and main amplifier can be used independently at the position of the speaker switching C system so that a multi-amplifier system can be constructed while taking advantage of the performance of the preamp and main amplifier sections.
Mid-range correction is more accurate with a tone selector that allows you to switch between two frequencies of up and down defeat.
The + and - power supplies of the main amplifier and the power supply of the preamplifier are equipped with independent ripple filter circuits to cut off ham components and stabilize the power supply.
It is equipped with functions such as low filter, high filter, loudness, headphone jack and muting switch.
|Type||Stereo pre-main amplifier|
|Main Amplifier Section|
|Total harmonic distortion factor||0.4% or Less (Rated Output)|
|Intermodulation Distortion Factor (SMPTE, 60 hz : 7 khz = 4 : 1)||0.4% or Less (Rated Output)|
|Power Band With (IHF)||10 Hz ~ 40,000 Hz (8 Ω)|
|Frequency characteristic||10 Hz to 70,000 Hz, ± 1 dB|
|Channel separation||50 dB or More (1 kHz, Rated Output)|
|Hum and noise (IHF)||100 dB or more|
|Input Sensitivity / Impedance (Rated Output, 1 kHz)||1V/50k Ω|
|Damping factor||20 (8 Ω Load)|
|Load impedance||4 Ω ~ 16 Ω|
|Output voltage||Maximum output voltage : 4 V
Rated output voltage : 1 V
|Total harmonic distortion factor||0.1% (Rated Output Voltage)|
|Frequency characteristic||15 Hz to 50,000 Hz, + 0.5 -1.5 dB|
|Hum and noise (IHF)||Phono1, 2 : 80 dB or more
MIC : 80 dB or more
Tuner, AUX : 85 dB or higher
|Input Sensitivity / Impedance
(Rated Output Voltage, 1 kHz)
|Phono1 : 2mV/50k Ω
Phono2 : 2mV/30k Ω, 50k Ω, 100k Ω
MIC : 2mV/50k Ω
Tuner : 180mV/100k Ω
AUX : 180mV/100k Ω
Tape Mon (Pin) : 180mV/100k Ω
Tape Recorder (Din) : 180mV/50k Ω
|Recorded output||Tape Rec(Pin):180mV
|Tone control||Bass : 20 Hz + 12 -8dB (2 dB step)
Midrange : 1,000 Hz, 2,000 Hz ± 5 dB (in 1 dB steps)
Treble : 20,000 Hz + 12 -8dB in 2 dB steps
|Tone selector||Midrange : Defeat, 1,000 Hz, 2,000 Hz
Loudness : + 8 dB (50 Hz), + 3 dB (10,000 Hz)
|SWITCH||High Filter : 10,000 Hz, -8dB (12dB/oct, NF Type)
Low Filter : 50 Hz, -8dB (12dB/oct, NF Type)
Muting : -20dB
|Power supply voltage||100 V, 50Hz/60Hz|
|Power consumption||400W at maximum input|
|External dimensions||Width 460x Height 140x Depth 305 mm|