Technics SU-9070(70A)
¥ 70,000 (around 1977)
Commentary
This flat pre-amplifier has a simple configuration with a flat amplifier in the equalizer circuit to eliminate coloring and improve basic performance.
The combination of 1% metal coating resistance and 2% polypropylene capacitor realizes excellent characteristics.
The first stage employs a differential amplifier circuit with a current mirror load to achieve a high gain of 60 dB and low noise.
The next stage consists of a voltage amplification stage with a pure resistance load. The distortion factor is 0.26% at a gain of 90 and 20 V output.
A subsonic filter switch is mounted on the equalizer stage.
In order to eliminate coloring due to changes in frequency characteristics, a flat amplifier without any accessory circuit is adopted.
Uses a 26-point high-precision attenuator type master level controller.
A subsonic filter switch is mounted on the equalizer stage.
Model Rating
| Type | Stereo flat preamp |
| Input Sensitivity / Impedance | Phono1, 2 : 2mV/47k Ω Tuner, Aux1, 2 : 150mV/47k Ω Tape deck1, 2, Playback : 150mV/47k Ω |
| Total harmonic distortion factor | 0.015% |
| Signal-to-noise ratio (IHF-A) | Phono1, 2 : 74 dB Tuner, Aux1, 2 : 100 dB |
| Frequency characteristic | Phono1 and 2 : RIAA standard curve ± 0.2 dB Tuner, AUx1, 2 : 20 Hz to 20 kHz + 0 -0.1 dB 2 Hz ~ 140 kHz + 0 -3dB |
| Phono maximum allowable input | 340mV |
| Output Voltage / Impedance | Output : 1V/600 Ω (Rating), 10V/600 Ω (Maximum) Tape deck1, 2, Rec out : 150 mv |
| Subsonic Filter | 20 Hz, -18dB/oct (equalizer) |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 8W |
| External dimensions | Width 450x Height 92x Depth 367 mm |
| Weight | 5.8kg |