ONKYO Integra A-815GT
¥ 56,800 (around 1981)
Commentary
A pre-main amplifier that uses Onkyo's proprietary Super Servo Integral technology.
In the Super Servo Integral Method, in addition to the W / Super Servo method, which suppresses noise components that cause distortion due to harmful ultra-low frequencies and power source impedance by the servomechanism applied to the + - poles of the output side, the electromotive force of the speaker caused by external factors such as other channel signals with time lag is corrected by a special method for the linearity of the output stage, so that harmful time difference distortion does not occur.
Linear switching method is adopted for the output stage.
As a result, the basic operating characteristics are equivalent to those of Class A amplification, which generates almost no harmful crossover distortion due to a special correction circuit, while efficiently performing Class B amplification.
It is compatible with MC cartridges, and in order to perform high-quality MC playback, it is equipped with a high-gain straight equalizer amplifier instead of a head amplifier or booster transformer.
In addition, by eliminating the tone amplifier and buffer amplifier and adopting a 2-amplifier configuration with direct input to a high-gain power amplifier, the circuit becomes simpler and higher sound quality is achieved.
In addition to simplifying the circuit by eliminating the tone amplifier, a direct tone system is adopted that eliminates the need for tone defeat.
It is composed of only passive elements without using active elements that affect sound quality. It is considered as a means to freely create desired sound quality from mere accessories of tone control.
The shielding materials for the circuit and other necessary parts are made of non-magnetic materials such as copper, brass and aluminum, avoiding the use of iron materials.
This prevents the magnetic flux generated from the circuit from generating harmful harmonics due to the non-linear characteristics of the magnetic path, thereby degrading the sound.
We have also examined the resistors used in parts from the aspect of sound quality, and newly developed resistors with improved sound quality are used for circuits that are important for sound quality.
In addition to excellent frequency characteristics and distortion characteristics, the conductive coating layer is intended to make the charge distribution uniform and improve magnetic characteristics, and plays an important role in sound quality.
It is equipped with a protection circuit that uses a high-speed relay to shut down the circuit when there is a DC leak in the speaker circuit.
Equipped with accessories such as various filters, muting, loudness, etc.
When a deck is connected to the REC output terminal, the recording signal always flows out. Therefore, even when recording is not performed, a recording switch is installed to prevent the recording signal from entering part of the circuit of the deck.
In addition, it is equipped with a function for recording back-channel programs such as recording the output of a tuner while enjoying a recording performance.
Model Rating
| Type | Super Servo Integral Stereo Pre-Main Amplifier | ||||
| Rated Output (Aux → SP out) | 55W + 55W (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) 0.005% (Phono MM → Rec Out, 3 V) 0.02% (Phono MC → Rec Out, 3 V) |
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| Intermodulation distortion factor (Aux → SP out) | 0.008% | ||||
| Powerbandwidth | 5 Hz ~ 100 kHz (Aux → SP out) | ||||
| Damping factor (1 kHz, 8 Ω) | 100 | ||||
| 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 Play : 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 | ||||
| Semiconductor used | 5 ic, 4 fet, 31 tr, 20 di | ||||
| Pwer | 100 V, 50/60Hz | ||||
| Power consumption (Electrical Appliance and Material Control Law standard) | 100W | ||||
| AC outlet | Unswitched-1 (200W) Switched : 2 (total 200W) |
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| External dimensions | Width 435x Height 125x Depth 392 mm | ||||
| Weight | 9kg |