Technics SE-A5
¥ 150,000 (around 1980)
Commentary
This is a stereo power amplifier that inherits the philosophy and quality of the SE-A1 and SE-A3 and is equipped with a linear feedback circuit.
A new class A system consisting of a synchronous bias circuit and a concentrated power block is equipped with a new linear feedback circuit.
This circuit was developed by putting the best effort into multiple feedback circuit technology. It forms an independent period circuit in the NFB loop that enables the naked amplification degree = ∞ of the amplifier. As a theoretical value, it realizes distortion = 0, pure gain without the influence of elements and power supply, and speaker drive without the influence of back electromotive force and wire.
A synchronous bias circuit is mounted, and a constant bias is supplied in synchronization with the pause cycle to each output transistor on the + side and the - side which are alternately paused in class B operation. The output stage is always in active state, and switching distortion is eliminated.
In addition, since the signal path and the bias current path are independent, the output stage maintains an appropriate operating point. Together with the function of a high-speed diode with square characteristics, crossover distortion is eliminated.
The output stage and power supply unit are integrated with an ingenious structure, and a concentrated power block is adopted that completely eliminates the adverse effects of electromagnetic fields.
In addition, magnetic materials with a high shielding effect are used for the chassis and cover to suppress external induction.
Four 10,000 μ F electrolytic capacitors are used for the power supply.
Equipped with full (120W + 120W) and limited (30W + 30W) output selection switches, you can enjoy driving 30W output with a huge power supply when the surroundings are quiet.
When limited is selected, meter lighting is turned off and power consumption is reduced.
It is equipped with a pure electronic protection circuit. If a DC component is generated at the speaker terminal, disconnect the speaker by relay.
This circuit also protects the amplifier against shorting of the speaker terminals or an abnormally low impedance load.
Equipped with a large power meter that can read directly from 0.0001W to 300W without range switching.
The response conforms to the characteristics of VU meter of BTS standard.
Model Rating
| Type | Stereo power amplifier | ||||
| Rated Output (20 Hz ~ 20 kHz) |
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| Total harmonic distortion factor |
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| TIM | Unmeasurable | ||||
| Power bandwidth | 5 Hz ~ 100 kHz (THD 0.007%) | ||||
| Frequency characteristic | DC ~ 20 khz + 0 -0.1 db DC ~ 200 khz + 0 -3dB |
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| Signal-to-noise ratio | 123dB | ||||
| Residual noise | 100 μ V | ||||
| Damping factor | 140 (8 Ω) | ||||
| Load impedance | Main or Remote : 4 Ω ~ 16 Ω Main & Remote : 8 Ω ~ 16 Ω |
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| Input Sensitivity / Impedance | 1V/47k Ω | ||||
| Output meter indication range | 0.0001W ~ 300W -60dB to + 5 dB |
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| Power supply voltage | 100 VAC, 50Hz/60Hz | ||||
| Power consumption | Full : 330W Limited : 100W |
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| External dimensions | Width 430x Height 178x Depth 416 mm | ||||
| Weight | 18.4kg |