ONKYO Integra A-817GT
¥ 56,800 (around 1981)
Commentary
A pre-main amplifier that uses Onkyo's proprietary Super Servo Integral technology.
In addition to canceling the components that cause distortion by the W / Super Servo system, the Super Servo / Integral System is adopted to suppress intermodulation due to electromotive force generated by the influence of other channels in the stereo sound field.
Linear switching method is adopted for the operation of the output transistor.
It is the same as class B in that it amplifies by using two transistors, and the linearity of the joint of the operation curve in question is corrected by a unique bias circuit to obtain linear operation characteristics as a whole.
And High fTBy using a power transistor, we succeeded in driving the switching distortion to a negligible range.
With a simple configuration of dual direct amplifiers consisting of an MC straight equalizer and a super servo integral type power amplifier, the MC cartridge can be played back with higher sound quality.
The MC straight equalizer amplifier has a high gain design that is mainly compatible with MC cartridges.
In addition, the bare characteristics of both the equalizer and power have been carefully examined, and a low feedback circuit with improved overall linearity and good audibility has been adopted.
As the gain of the power amplifier is increased, the direct tone method without the tone amplifier is adopted.
In this method, the loudness circuit associated with the volume control is used to vary the tone, so the circuit consists of only passive elements that do not affect the sound quality.
This allows for higher fidelity playback even with the tone control.
A special noise-improving resistor is used in the main circuit.
The frequency characteristics and strain characteristics are better than those of the conventional type, and the conductive coating layer shows excellent performance in terms of uniform charge distribution and magnetic characteristics.
Non-magnetic metals such as copper, brass, and aluminum are used in place of iron to prevent the generation of higher-order harmonics harmful to audibility due to the delicate magnetic flux generated from the circuit.
The phono input pin terminal, which receives a weak input voltage, is gold-plated.
Model Rating
| Type | Super Servo Integral Stereo Pre-Main Amplifier | ||||
| Rated Output (Aux → SP out) | 80W + 80W (20 Hz to 20 kHz, 8 Ω, both channel drive) | ||||
| Total harmonic distortion rate (20 Hz to 20 kHz) | 0.008% / 0.007% (AUX → SP Out, at rated output / at 1/2 output) 0.003% (Phono MM → Rec Out, 3 V) 0.015% (Phono MC → Rec Out, 3 v) |
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| Intermodulation distortion factor (Aux → SP out) | 0.008% | ||||
| 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 High MC : 2.9mV/100 Ω Phono MC : 280 μ V/330 Ω Tuner, AUX, Tape Play : 150mV/47k Ω |
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| Phono maximum allowable input (1kHz/10kHz, 0.05%) |
Phono MM:250mV/1200mV Phono High MC:250mV/1200mV Phono MC:23mV/110mV |
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| Output Voltage / Impedance | Tape Rec1, 2 : 150mV/2.2k Ω | ||||
| S/N ratio (IHF A-short) | Phono MM:87dB Phono MC:72dB 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 | ||||
| Semiconductor used | 3 ic, 4 fet, 45 tr, 22 di | ||||
| Pwer | 100 V, 50/60Hz | ||||
| Power consumption | 130W (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 142x Depth 392 mm | ||||
| Weight | 11kg |