ONKYO Integra A-820GT
¥ 159,000 (around 1981)
Commentary
A pre-main amplifier that uses Onkyo's proprietary Super Servo Integral technology.
By using the Super Servo Integral Method, the electromotive force of the speaker caused by external factors such as time-lagged signals of other channels is compensated 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 final output stage.
In this system, the basic operating characteristics are class B with two transistors, but linear operating characteristics are obtained by correcting the connection between the two operating characteristics using a special bias circuit.
In addition, aiming at effective improvement of switching distortion, a high f with sufficient margin is obtained.TPower transistor is used and excellent distortion factor characteristics are obtained.
It is a 2-amp configuration with only the MC-compatible straight equalizer and the power section of the super servo integral system.
In order to take advantage of the excellent quality of the MC cartridge in particular, it avoids head amplifiers and step-up transformers, and uses an equalizer designed with an emphasis on the use of the MC cartridge, thus improving the sound quality when using the MM cartridge.
In addition, by improving the bare characteristics of both the equalizer and power section, and by adopting a low feedback system of less than 1 / 10 of the conventional one, we have achieved the pursuit of audible quality and stable operation.
In addition, in order to improve sound quality, we have adopted a tone control method using a volume-linked loudness circuit composed only of passive elements instead of the conventional method in which extra gain is always kept in preparation for tone boost.
In addition to the tone control circuit, a softness circuit is installed so that two different tone characters can be selected.
This circuit can be used for low-grade program sources by controlling the resolution.
The power supply section is designed with sound quality in mind by adopting a twin wide type large 2-transformer system and a multi-tab type low-impedance Chemicon directly connected to a printed circuit board.
Non-magnetic materials such as copper, brass, and aluminum are used for the main parts related to sound quality to suppress the influence of high order harmonics that are harmful to the auditory sense due to the nonlinear characteristics of the magnetic path.
Newly developed special tone improving type resistor is adopted.
Equipped with protective circuit with large capacity relay.
Equipped with a pre-out terminal that can record control signals.
A gold-plated pin plug has been adopted in consideration of minute current.
Uses a large heat sink with excellent heat radiation effect.
Model Rating
| Type | Super Servo Integral Stereo Pre-Main Amplifier | ||||
| Rated Output (Aux → SP out) | 110W + 110W (20 Hz ~ 20 kHz, 8 Ω, Both channel drive) | ||||
| Total harmonic distortion rate (20 Hz to 20 kHz) | 0.008% / 0.006% (AUX → SP Out, at rated output / at 1/2 output) 0.003% (Phono MM → Rec Out, 3 V) 0.01% (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 : 2.5mV/47k Ω, 100k Ω Phono High MC : 2.5mV/100 Ω Phono MC : 130 μ V/100 Ω, 330 Ω Tuner, AUX, Tape Play : 150mV/47k Ω |
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| Phono maximum allowable input (1kHz/10kHz, 0.05%) |
Phono MM:300mV/1400mV Phono High MC:300mV/1400mV Phono MC:16mV/80mV |
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| Output Voltage / Impedance | Tape Rec1, 2 : 150mV/2.2k Ω Pre Out : 1.5V/600 Ω |
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| S/N ratio (IHF A-short) | Phono MM:86dB Phono MC:69dB 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 | + 4 dB, + 6 dB (100 Hz) | ||||
| Subsonic filter | 15 Hz 20 Hz, 6dB/oct. | ||||
| Muting | -20dB | ||||
| Semiconductor used | 6 ic, 6 fet, 72 tr, 49 di | ||||
| Pwer | 100 V, 50/60Hz | ||||
| Power consumption (Electrical Appliance and Material Control Law standard) | 200W | ||||
| AC outlet | Unswitched-1 (200W) Switched : 2 (total 200W) |
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| External dimensions | Width 465x Height 162x Depth 431 mm | ||||
| Weight | 21.5kg |