Technics SU-V7A
¥ 64,800 (released in 1982)
Commentary
This new class A integrated amplifier is equipped with a computer drive circuit that eliminates transient crossover distortion during music signal reproduction.
The computer drive monitor allows you to check the operating status of the circuit at a glance.
When the power switch is turned on, the Preheat LED on the display located in the lower right of the front panel blinks and the Preheat LED immediately enters the preheat state. The output transistor reaches the ideal state in about 20 seconds, and the Auto LED and the green sign on the Computer Drive indicate that the circuit has entered a stable operating state.
It employs a concentrated power block that virtually eliminates high-frequency distortion caused by electromagnetic radiation. By concentrating the output stage and power supply in an ingenious configuration, the adverse effects of electromagnetic fields are completely eliminated.
A powerful power supply circuit composed of a newly designed power transformer with low loss and large capacity and a low-loss, high-capacity electrolytic capacitor provides a stable voltage at all times. Linearity is also improved by the adoption of a large chip size output transistor.
In order to realize a slim form with a panel height of 2.5U (1U = 43.6 mm), a heat pipe radiator is used to disperse heat generated by the output transistor horizontally.
It is equipped with a pure electronic protection circuit utilizing a microcomputer. The computer judges DC leakage, short circuit of the speaker terminal, abnormal temperature rise inside the amplifier, etc. and the speaker is disconnected by relay.
The newly developed low-noise dual-FET differential amplifier is used for the first stage of the phono equalizer, and a high-gain IC of 100 dB or higher is used for the next stage. This is an MC-based high-gain design.
A straight DC amplifier configuration is adopted. Both the M and MC are ICL equalizers that eliminate input capacitors. Therefore, during straight DC operation, the phono input only passes through one coupling capacitor. During high-level input, it is amplified directly to the speaker terminal by a high-gain DC amplifier, enabling faithful waveform transmission.
The effect of the linear feedback circuit that enables nearly 100% NFB is also used in the tone control circuit. It consists of bass that uses the NF loop of the main amplifier and treble that uses the NF-CR type.
Equipped with dedicated connection terminals for external accessories such as graphic equalizer, microphone mixing amplifier and Ambience controller.
Independent rec/input selectors enable FM air check and tape dubbing during record listening.
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Model Rating
| Type | Integrated DC amplifier |
| <Overall characteristics of Tuner, Aux → SP out> | |
| Effective output (20 Hz to 20 kHz) | 100W + 100W (8 Ω, 0.003%) |
| Total harmonic distortion factor | 0.002% (Rated Output -3dB, 20 hz to 20 khz) |
| TIM | Unmeasurable |
| Output bandwidth | 5 Hz ~ 100 kHz (THD 0.02%) |
| Frequency characteristic | 20 Hz ~ 20 kHz + 0 -0.1 dB 5 Hz ~ 170 kHz + 0 -3dB |
| Signal-to-noise ratio (IHF-A) | 104 dB (straight DC) |
| Residual noise | 0.5 mV (Straight DC) |
| Damping factor | 80 (8 Ω) |
| Load impedance | Main or remote : 4 Ω ~ 16 Ω |
| <Other characteristics> | |
| Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC : 170 μ V/220 Ω Tuner, Aux, Tape : 150mV/22k Ω |
| Phono SN ratio | MM : 88 dB (2.5 mV input) MC : 72 dB (250 μ V Input) |
| Phono frequency characteristics | 20 Hz to 20 kHz, RIAA ± 0.5 dB |
| Tone control | Bass : ± 10 dB (50 Hz) Treble : ± 10 dB (20 kHz) |
| Filter | Subsonic : 30 Hz, -6dB/oct. |
| Loudness control | + 9 dB (50 Hz, Volume -30dB) |
| <General> | |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 137W |
| External dimensions | Width 430x Height 120x Depth 362 mm |
| Weight | 10.0kg |