Technics EAA-2008/SU-2008/SU-30A/Technics 30A
¥ 74,000 (released in March 1968)
¥ 79,500 (around 1970)
Commentary
This tube type preamplifier was developed using Technics technology.
The model number has been changed 3 times : EAA-2008, SU-2008 and SU-30A.
A ripple filter using a transistor is incorporated in the rectifier circuit of the heater to minimize hum noise by igniting with DC without ripple, and noise level is reduced by shielding the power supply and adopting low noise resistance.
The equalizer circuit consists of 3-stage NF type, and the buffer amplifier consists of SRPP (Shunt Regulated Push Pull) type cathode follower circuit.
In order to improve the accuracy of the playback characteristics of the equalizer circuit and to avoid unnecessary coloring, we use capacitors and resistors with precision within ± 1% error. In addition, the deviation from the RIAA curve is kept within ± 0.3 dB by measuring and adjusting each unit when it is assembled.
The volume employs a special 4-series volume that adjusts the output of the tone amplifier simultaneously, reducing residual noise.
The tone control circuit adopts Technics original system using special double volume.
In this method, when one side is in contact with the resistor, the other side is in contact with the silver conductor so that only one capacitor is inserted. Also, at the midpoint, both brushes are on the silver conductor so that flat characteristics can be obtained.
Model Rating
Type | Tube type preamplifier | |||||||||||||||||||||
Input Sensitivity / Impedance | Phono1, 2 : 1.2mV/47k Ω Tuner1, 2 : 70mV/150k Ω AUX1 : 0 ~ 70 mV Adjustable / 70k Ω AUX2 : 70mV/150k Ω Tape Head 9.5 cm, 19 cm : 1.6mV/470k Ω MIC : 1.4mV/47k Ω |
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Maximum allowable input (1 kHz, 0.1% distortion rate) |
Phono1, 2 : 400 mV Tuner1, 2 : 50 v AUX1, 2 : 50 V Tape Head 9.5 cm, 19 cm : 500 mv MIC:400mV |
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Tape monitor (at rated output) |
Rec out : 70mV/500 Ω Playback : 70mV/150k Ω Rec/Play (DIN) : 70mV/90k Ω, 150k Ω |
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Output Level / Impedance | 15V/500 Ω (Maximum Output) | |||||||||||||||||||||
Signal-to-noise ratio (IHF, A-network) |
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Total harmonic distortion rate (1 kHz) | Not more than 0.1% | |||||||||||||||||||||
Frequency characteristic | Phono1 and 2 : within ± 0.3 dB deviation from RIAA standard curve Tuner1, 2 : 5 Hz to 50 kHz, ± 0.5 dB AUX1, 2 : 5 Hz to 50 kHz, ± 0.5 dB
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Semiconductor used |
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Pwer | 100 VAC, 50/60Hz | |||||||||||||||||||||
Power consumption | 35VA | |||||||||||||||||||||
External dimensions | Width 420x Height 150x Depth 250 mm | |||||||||||||||||||||
Weight | 7.6kg |