Technics SU-A4MK2
¥ 250,000 (released in 1983)
Commentary
Control amplifier equipped with amorphous MC step-up transformer.
The phono equalizer circuit is equipped with an amorphous MC step-up transformer for the first time in the world. It achieves a wide bandwidth of 15 Hz to 100 kHz ± 0.2 dB and a high SN ratio of 82 dB at the MC input.
In addition, the input sensitivity of Phono1 can be switched to a total of four levels : two MC levels and two MM levels.
By making all stages A class operation, switching distortion and crossover distortion are eliminated.
The circuit is fully DC up to the output terminal.
Equipped with a SEPP buffer amplifier, it realizes an output impedance of 2 Ω and improves high frequency characteristics.
Model Rating
Type | Stereo DC control amplifier |
Input Sensitivity / Impedance | Phono1, 2 mm : 2.5mV/47k Ω Phono1 mm : 1mV/47k Ω Phono1 MC : 70 μ V/30 Ω, 250 μ V/470 Ω |
Total harmonic distortion rate (20 Hz to 20 kHz) | Tuner, Aux, Tape, Phono MM, MC : 0.001% (VR max, 2 v output) |
Signal-to-noise ratio (IHF-A) | Phono MM : 92 dB (2.5 mV input) Phono MC : 82 dB (100 μ V input) Tuner, Aux, Tape : 106 dB |
Frequency characteristic | Phono MM : 20 Hz to 100 kHz, RIAA ± 0.2 dB Phono MC/MM : 20 Hz to 20 kHz, RIAA ± 0.15 dB Tuner, Aux, Tape : DC ~ 20 khz + 0 -0.1 db DC ~ 200 khz + 0 -3dB |
Maximum Allowable Input (1 kHz, RMS) | Phono MM:160mV Phono MC:16mV |
Shelving tone | Super bass : 0 to + 10 dB (20 Hz) Bass : + / - 5 dB (50 Hz) Treble : ± 5 dB (20 kHz) Super treble : ± 10 dB (50 kHz) |
Turnover frequencies | Super bass : 75 Hz, 150 Hz (+ 12dB/oct.) bass:500Hz treble:2kHz super treble:8kHz |
Filter | Subsonic Filter : 20 Hz, -12dB/oct. High Filter : 7 kHz, -6dB/oct. |
Loudness control | + 7 dB (50 Hz, VR-30dB) |
Output Voltage / Impedance | Rec out : 150mV/600 Ω Pre out : 2V/2 Ω |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption | 12W |
External dimensions | Width 430x Height 97x Depth 360 mm |
Weight | 8kg |