ONKYO Integra M-509

Commentary

A stereo power amplifier developed as the culmination of the "W ・ Super Servo System" which is a further development of the "Super Servo System".

The W ・ Super Servo method uses servo feedback from both + - terminals of the output to cancel the distortion components generated inside the amplifier. This method suppresses noise components caused by the internal impedance of the power supply and distribution system and the internal impedance of the power supply, and enhances sound resolution.
The + side servo cancels at least 40 dB of the ultra-low frequency component that is superimposed on the music signal and intended to flow into the speaker, thereby suppressing harmful intermodulation.
The - side servo electrically cancels noise components caused by various impedances of the power supply, for example, internal resistance of the capacitor, contact resistance of each part, and resistance of lead wires.

Output stage is High f with 3-stage Darlington configuration._TA power transistor is used.
In addition, the operating characteristics of the power transistor are improved by using Onkyo's original linear switching method to improve the distortion factor, and while B-class operation is achieved, characteristics close to A-class are obtained.

The power supply unit uses an ultra-large twin-winded transformer, and the power supply capacitor is designed for audio equipment after careful listening and correlation with physical properties. The capacitor is designed to have low characteristics such as a distortion factor of -150dB or higher for the third high-frequency level at 10 kHz, a total equivalent series resistance (E ・ S ・ R) of 0.009 Ω or less for the lead-out leads and terminals, and a loss tan δ of 0.25 or less.
In addition, the power supply / distribution to each unit section and the ground line are made of copper plate bus (bus line) lines to ensure low impedance.

Thermal gradients occur due to differences in heat capacity between each block of the final, such as a sudden change from continuous large amplitude operation to small amplitude operation.
To prevent this from destabilizing the bias current value of the power section and affecting the reproduction of the low-level signal, a 3-point sensing bias circuit is installed in the output stage. By detecting the temperature difference between the pre-driver stage, the driver stage, and the power transistor, and controlling the bias, stable constant distortion rate driving is enabled.

Every part, lead, and solder has been carefully examined through thorough hearings.

Model Rating

Type	W Super Servo Type Stereo Power Amplifier
Amplifier Unit
Effective output (20 Hz to 20 kHz)	280W + 280W (4 Ω) 200W + 200W (8 Ω)
Dynamic Power (1 kHz)	280W + 280W (8 Ω)
Total Harmonic Distortion Factor (THD, 20 Hz to 20 kHz, Effective Output)	Not more than 0.003%
Intermodulation distortion factor (70 Hz : 70 kHz = 4 : 1 at effective output)	Not more than 0.003%
Power Band Wiz (IHF-3dB, THD 0.2%)	5 Hz to 100 kHz
Gain	28.5dB
Frequency characteristic	1 Hz ~ 100 kHz + 0 -1.5 dB
S/N (IHF-A network, input shunt)	120dB
Input Sensitivity / Impedance	1.5V/47k Ω
Speaker load impedance	4 Ω ~ 16 Ω
Damping factor (8 Ω, 1 kHz)	200
Output terminal	Speaker System-1, System-2, Headset
Transient killer operating time	Power on/off:5sec/100msec
Meter Part
Range switching	x1(0dB=200W) x0.1(0dB=20W)
Indication range	-40dB to -4dB
Indication accuracy	0 ± 1 dB, -10 ± 2 dB, -20 ± 3 dB
Response speed (∞ → 0 dB)	100 μ sec
Return speed (0 dB → -20dB)	1sec
<General>
Semiconductor used	Transistor : 82 FET : 4 pcs IC : 7 Diode : 86 pcs
Power supply voltage	100 VAC, 50Hz/60Hz
AC Output	Power switch not linked, 600W maximum
Power consumption (Electrical Appliance and Material Control Law)	320W
External dimensions	Width 480x Height 191x Depth 439 mm
Weight	31kg