ONKYO Integra A-815D
¥ 56,800 (around 1981)
Commentary
A stereo pre-main amplifier that adopts the W super servo system.
In the W Super Servo system, all components originated in the amplifier are canceled by the feedback loop of the servo operational amplifier separately provided.
As a result, harmful components are skillfully cancelled and only the incoming music signal is transmitted in high purity.
Linear switching method is adopted for power amplification at the final output stage.
Although the basic operating characteristics of this system are highly efficient class B, it has the same operating characteristics as class A because it smooths the amplification part of the two transistors and does not generate harmful crossover distortion.
In order to support MC cartridges, it is equipped with a straight equalizer amplifier with MC as the main element, rather than a simple head amplifier or step-up transformer.
In addition, the quality of the MM cart has been upgraded accordingly.
In addition, the tone circuit and buffer amplifier are omitted, and a 2-amplifier configuration is used for direct input to a high-gain power amplifier, giving priority to sound quality.
It is equipped with a direct-tone tone control consisting only of passive elements that have little effect on sound.
We aim to achieve purer waveform transmission by using non-ferrous metals in the main parts of the mechanical components to suppress harmonic distortion.
Model Rating
| Type | W super servo type pre-main amplifier | ||||
| Rated Output (AUX → SP Out) | 55W + 55W (8 Ω, 20 Hz to 20 kHz, both channel drive) | ||||
| Total harmonic distortion rate (20 Hz to 20 kHz) | 0.015% / 0.012% (Aux → SP out, Rated Output / 1/2 Output) 0.005% (Phono MM → Rec Out, 3 V) 0.02% (Phono MC → Rec Out, 3 V) |
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| Intermodulation distortion factor (Aux → SP out) | 0.01% | ||||
| Powerbandwidth | 5 Hz ~ 100 kHz (Aux → SP out) | ||||
| Damping factor | 100 (1 kHz, 8 Ω) | ||||
| Frequency characteristic |
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| Input Sensitivity / Impedance | Phono MM : 2.9mV/47k Ω Phono MC : 350 μ V/330 Ω Tuner, AUX, Tape Play1, 2 : 150mV/47k Ω |
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| Phono maximum allowable input (1kHz/10kHz, 0.05%) |
Phono MM:230mV/1100mV Phono MC:30mV/145mV |
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| Output Voltage / Impedance | Tape Rec1, 2 : 150mV/2.2k Ω | ||||
| S/N ratio (IHF A-short) | Phono MM:83dB Phono MC:67dB Tuner, AUX, Tape Play1, 2 : 100 dB |
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| Tone Control (Vol-16dB) | Bass : ± 8 dB (70 Hz) Treble : ± 8 dB (20 kHz) |
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| Loudness | +6dB(100Hz) | ||||
| Subsonic filter | 15 Hz, 6dB/oct. | ||||
| Muting | -20dB | ||||
| Pwer | 100 V, 50/60Hz | ||||
| Power consumption | 105W (Electrical Appliance and Material Control Law Standard) | ||||
| AC outlet | Unswitched-1 (200W) Switched : 2 (total 200W) |
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| External dimensions | Width 435x Height 125x Depth 385 mm | ||||
| Weight | 9.5kg |