ONKYO Integra M-506R
¥ 170,000 (around 1981)
Commentary
This is a Super Servo / Integral Stereo Power Amplifier that analyzes the amplifier not only as a single electric circuit but also including the acoustic aspect of the playback sound field, and thoroughly investigates the problem of time difference distortion.
In addition to Onkyo's original W / Super Servo system, Super Servo Integral system is used to reduce the influence of the electromotive force of the speaker.
When the voice coil of the speaker vibrates, an electromotive force is generated in the coil, a microphone effect, which affects the playback sound. The Super Servo Integral Method employs a circuit that reduces the effect of this electromotive force to -20dB or less. Positive and negative feedback is applied only to the current amplification stage by the linearity correction circuit, and the linearity of this stage is dramatically improved, and time difference distortion is suppressed.
The final transistor operates using a linear switching method.
Similar to class B operation, this method is amplified by two transistors. In this case, the linearity of the joint of the operation curve is corrected by a special bias circuit to obtain linear operation characteristics. As a result, crossover distortion is reduced, and characteristics close to class A operation can be obtained while maintaining the advantage of class B operation.
And High fTBy using a power transistor, the switching distortion is suppressed to a negligible range.
It is equipped with a large peak meter in which logarithmic compression and peak hold are performed by a monolithic IC with good stability and dispersion between right and left is suppressed.
In order to obtain high-speed response, it is driven by a dedicated meter drive circuit using an operational amplifier, and the level can be switched from 0 dB to 130W or 13W with a front switch.
A monolithic IC is used for the protection circuit to improve stability, detect DC leak voltage appearing at the speaker terminal and overcurrent of the power stage, and shut off the relay to protect circuit components in case of emergency.
A highly reliable gold-plated silver contact relay is used for the speaker switching relay, and the use of para-connection prevents the damping factor from deteriorating.
The low-pass filter for DC voltage detection is also independent on the left and right sides, so that it can operate even when the polarity of the left and right sides are different.
A twin-wide type large power transformer is used for the power supply section, and a multi-tab type low-impedance wide-range Chemi-Con is used as a low-inductance circuit directly connected to a bus earth for the Chemi-Con for rectification after careful consideration.
In addition, the power supply / distribution to each section and the ground line are designed to be low impedance.
It uses an autotracking bias system that detects local temperature changes in each part and provides a stable bias supply.
Model Rating
Type | W / Super Servo Type Stereo Power Amplifier |
Amplifier Unit | |
Effective output (20 Hz to 20 kHz) | 170W + 170W (4 Ω) 130W + 130W (8 Ω) |
Dynamic Power (1 kHz) | 200W + 200W (8 Ω) |
Total Harmonic Distortion Factor (THD, 20 Hz to 20 kHz) | 0.003% or Less (Effective Output) 0.002% or Less (at 65W output) |
Intermodulation distortion factor (SMPTE70Hz : 7 khz = 4 : 1) | 0.003% or Less (Effective Output) |
Power Band Wiz (IHF-3dB, THD 0.2%) | 5 Hz to 100 kHz |
Gain | 30dB |
Frequency characteristic | 1 Hz ~ 100 kHz + 0 -1.5 dB |
Signal-to-noise ratio (IHF-A network input shunt) | 120dB |
Input Sensitivity / Impedance | 1V/47k Ω |
Speaker load impedance | 4 Ω ~ 16 Ω |
Damping factor (8 Ω, 1 kHz) | 180 |
Output terminal | Speaker System1, 2 Headphone |
Transient killer operating time | Power on:5sec Power off:100msec |
Meter Section | |
Range switching | x1(0dB=130W) x0.1(0dB=13W) |
Indication range | -40dB to + 4 dB |
Indication accuracy | 0 ± 1 dB -10 + / - 2 dB -20 + / - 3 dB |
Response speed | 100 μ sec (∞ → 0 dB) |
Return speed | 1 sec (0 dB → -20dB) |
<General> | |
Semiconductor used | Transistor : 49 FET : 8 IC : 6 Diode : 48 pcs |
Pwer | 100 VAC, 50Hz/60Hz |
AC outlet | Up to 600W Power switch not linked : 1 system |
Power consumption | 230W (Electrical Appliance and Material Control Law) |
External dimensions | Width 450x Height 174x Depth 422 mm |
Weight | 18.5kg |