Audio Database

QRX-3000
Commentary

A 4-channel receiver with built-in newly developed QS Barrio matrix circuit that supports all 4-channel systems.

The QS QS Barrio matrix circuit is incorporated in the QS synthesizer / decoder section.
The QS Barrio matrix circuit is composed of square matrices and phase shifters, etc., and emphasizes natural sound field generation while improving separation and sound quality.
In the newly developed QS Barrio matrix circuit, the matrix coefficient of the input signal is changed instantaneously to control the source so that the directivity becomes clearer, and the separation is improved. Theoretically, the QS Barrio matrix circuit can achieve infinite separation between each channel by selecting the control level of the matrix coefficient. However, from the viewpoint of music playback, it is adjusted to the optimum level of audibility. This control uses a phase discriminator that detects the phase of the input signal.

A 2-stage direct NF circuit is used for the equalizer amplifier in the amplifier section.

The tuner section uses a dual-gate MOS type FET and a precision 3-row varicon.
The IF section uses a ceramic filter with four elements and two stages and an IC to improve sensitivity and selectivity.

A constant voltage circuit is used for the power supply.

Equipped with a function switch for selecting 4-channel effects.

Equipped with various 4-channel control functions.

The headphone jack can be used on the front and rear separately.

24. QS Synthesizer / Decoder
27. Power supply unit
30. Tone Control
33. Low / High Filter
36. Tuning knob between FM/AM tuning channels
39. Tape monitor switch
25. Amplifier section
28. Power Switch
31. balance control
34. Function Switches
37. Loudness Switch
26. Tuner Section
29. Headphone Jack
32. Volume Switch
35. Selector switch
38. FM Muting
 
Model Rating
Type 4-channel receiver
Synthesizer Unit
Synthesizer / decoder Sansui QS Regular Matrix Circuit
(built-in QS Barrio matrix circuit)
Pre-Main Amplifier Section
Music power (IHF, 1 kHz) 100W (4 Ω)
Effective power 15W/15W/15W/15W / 15 w (8 Ω, each channel operation, 1 kHz)
8W + 8W + 8W + 8W + 8W (8 ohm, 4 ch operation, 20 hz to 20 khz)
Total harmonic distortion factor (at rated output) Not more than 0.5%
Intermodulation distortion factor (at rated output) 0.5% or Less (70 Hz : 7 kHz = 4 : 1 SMPTE)
Power Band With (IHF) 20 Hz to 30 kHz
Frequency characteristic 30 Hz to 30 kHz
Input Sensitivity / Impedance Phono : 2.5mV/50k Ω (1 kHz at rated output)
Phono maximum allowable input 100 mV (total harmonic distortion rate 0.5% or less)
Hum and noise (IHF) Phono : 70 dB or more
FM Tuner Section
Sensitivity (IHF) 2.5 μ V
Selectivity 50 dB or more
Total harmonic distortion factor mono:0.5%
stereo:0.8%
Signal-to-noise ratio Mono : 60 dB or more
Stereo separation 35 dB or More (1 kHz)
Capture Ratio (IHF) 2.5 dB or less
Image rejection 45 dB or more
<AM Tuner Section>
Sensitivity 50dB/m (bar antenna)
Selectivity 25 dB or more
<General>
Semiconductor used Transistor : 88
Diode : 50 pcs
FET : 3
IC : 1
Zener diode : 1 unit
Power consumption 62W (rated)
110 VA (max)
External dimensions Width 505x Height 140x Depth 330 mm
Weight 11.5kg