ONKYO Integra T-445XX

Commentary

FM/AM tuner using W stabilizer system.

In order to achieve even higher levels of reception performance and sound quality, which are the development themes for the Integra tuner, we developed and installed a W stabilizer system.
The W stabilizer method is an improved method using two stabilizers, an electrical D. R (Direct Receiving) stabilizer and a mechanical X stabilizer. In both electrical and mechanical aspects, the W stabilizer method pursues low distortion and stability of the tuner circuit.

The D. R stabilizer is a circuit developed to directly receive a wide dynamic range source such as CD. The I. D. S (Isolated Digital System) and D. C. I (Distortion Correcting IF System) reduce digital noise generated inside the tuner to obtain high S/N ratio and achieve high selectivity and low distortion rate.

The X stabilizer is made of a special alloy of PbSb. It is the most susceptible to speaker vibration and mechanically suppresses the local vibration that causes the music signal to become muddy.

In the I. D. S, the digital and analog sections are separated during broadcast reception by automatically switching between the PLL mode required for receiving and the mode required for listening to the broadcast, thereby reducing digital noise and improving S/N.

L. T. D (Linear Tracing Detector) is used for the detector.
This system directly detects 10.7 MHz signals. It is a closed-loop system in which signals delayed by 90 ° from the IF signal are detected by tracing the IF signal linearly. Therefore, S/N is good.

Using a D.C. I circuit that compensates for the distortion generated by the IF filter while maintaining a selectivity of 60 dB, it achieves a low distortion factor.
The IF stage employs wide/narrow 2-stage switching.

The MPX circuit is simplified using a Digital Computed Decordor (D.C. D).
By creating a pure 38 kHz (sine wave) for left and right separation and using an analog operation method for the input composite signal, there is no generation of harmonics and no need for a filter to improve separation and distortion factor.

The front-end section has been designed to improve intermodulation by adopting a two stage series buffer from the station and two stage RF switching.

AM/FM random such as AM/FM random 20-station memory, preset scan and 5-station timer program.

Model Rating

Type	FM/AM Tuner
FM Tuner Section
Receiving frequency	76.1 mhz to 89.9 mhz
Practical Sensitivity (75 Ω / IHF)	Boost on : 0.9 μ V/10.3 dBf Boost off : 4.0 μ V/23.3 dBf
S/N50dB sensitivity (75 Ω / IHF)	2.0 μ V/17.3 dBf
Intermodulation interference ratio (± 1 MHz / ± 2.5 MHz)	boost on:88dB/90dB boost off:103dB/110dB
Image Interference Ratio (83 mhz)	boost on/off:90dB
IF Interference Ratio (83 MHz)	boost on/off:100dB
Spurious interference ratio	boost on/off:100dB
Two signal selectivity	wide:60dB narrow:85dB
Strain Rate (400 Hz)	mono wide:0.0055% narrow:0.15% stereo wide:0.008% narrow:0.4%
Stereo separation	1kHz wide:68dB narrow:45dB 100 Hz to 10 kHz wide:45dB narrow:40dB
AM suppression ratio	wide:62dB narrow:50dB
Capture ratio	wide:1.0dB narrow:2.0dB
Signal-to-noise ratio	mono:100dB stereo:90dB
Frequency characteristic	20 Hz to 15 kHz + 0.2 -0.8 dB
Carrier leak	-65dB
Antenna impedance	75 Ω unbalance
Output Voltage (400 Hz)	500mV(100%)
Output impedance	1.9k Ω
<AM Tuner Section>
Practical sensitivity	200 μ V/m (loop antenna)
Image interference ratio (999 kHz)	40dB
IF interference ratio (999 kHz)	57dB
2 signal selectivity (selectivity + / - 10k)	35dB
SN ratio (100mV/m)	50dB
Strain Rate (400 Hz)	0.3%
Output Voltage (400 Hz, 30%)	150mV
Output impedance	1.9k Ω
<General>
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law)	17W
External dimensions	Width 435x Height 73x Depth 368 mm
Weight	6.1kg