What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

Pioneer QX-949 (1974)

Pioneer's QX-949 stereo receiver is the most complete 4-channel unit now on the market. Boasting a built-in CD-4 demodulator as well as regular matrix and SQ matrix decoding circuitry - plus a prodigious power output - the QX-949 is prepared to deliver superlative sound from all 4-channel discs, tapes and FM broadcast now available today. It is truly a one-of-a-kind receiver, Pioneer's most distinguished contribution to the art of 4-channel sound. Inclusion of the CD-4 demodulator means that, for the first time, one professional 4-channel receiver is capable of decoding and reproducing all 4-channel sources. No longer must the hi-fi enthusiast add multiple additional components, like a demodulator, to his system to achieve perfect 4-channel sound. The QX-949 does it all, and does it better than any other receiver. Power of this unit is vast - 40W x 4 of continuous RMS power with all 4 channels driven at 8 ohms. And this figure is measured at the most critical listening range, within the audible human range of 20 - 20,000 Hz. Better yet, when you choose to use the QX-949 for conventional two-channel sound, it will give you 60W x 2 of continuous RMS power, by the use of a new "Power Boosting Circuit". And that's a lot of power by anyone's standards. The AM/FK tuner section of the QX-949 is a classic of sensitivity and selectivity, thanks to its four-gang variable capacitor and phase-linear ceramic filters.

Other features include a 4-channel level indicator that illuminates any adjustments you might make'when listening to 4-channel sound. The unit also handles four pairs of speaker systems (two in the front, two in the rear, each operated independently or simultaneously) and three tape decks for tape-to-tape duplication. The QX-949 also hooks up two turntables and an additional auxiliary source. For any kind of 4-channel sound-regular matrix, CD-4, SQ or discrete, along with regular two-channel sound - the QX-949 is a milestone event in music reproduction.

The Latest CD-4 Demodulator

Playing CD-4 records with full fidelity and space expanding four channel realism is easy withthe Pioneer QX-949. They have a built-in CD-4 demodulator of the latest design, clear sound localisation in the four channels is achieved by simple manipulation of CD-4 separation controls.

SQ Full Logic Matrix Decoder

Newly developed integrated circuits for the matrix logic and gain control section of this advanced full logic SQ decoder help to obtain the very best separation between the front and rear, as well as the left and right channels, essential for the true to life reproduction of sound field when you play an SQ encoded four channel record throught either the Pioneer QX-949.

Regular Matrix (RM) Decoder

The RM position on the four channel mode selector of both Pioneer QX-949 is to be used when you play any matrix four channel record other than SQ or wish to synthesise four channel stereo from a normal stereo disc.

Other Four Channel Features:

A 4 CH-MPX out terminal is located on the back panel enabling you to hook up an FM four channel adaptor to receive FM discrete four channel broadcast when they become available in the future.

A four channel level indicator.

In addition to this advance quadraphonic performance the QX-949 A offers excellent FM - AM tuner performance with very wide stereo separation thanks to:

FM front end with MOS FET

Local oscillator with buffer circuit (QX-949 A)

Excellent phase linearity and high selectivity.

High performance multiplex integrated circuit.

Effective FM muting switch.

Linear FM dial scale and tuning meter.

Outstanding AM section

All The Power You Need For A BIg Four Channel Sound; QX-949 produce 40 watts per channel at 8 ohms (4-channel driven) 20 Hz to 20 kHz with no more than 0,3% THD

Specifications QX-949

Audio Section

Continuous power:

4 x 58 W; 2 x 85 W (1 kHz, 4Ω)

4 x 44 W; 2 x 65 W (1 kHz, 8Ω)

4 x 40 W; 2 x 60 W (20 - 20,000 Hz, 8Ω)

75 W/ 4-ch.; 100 W/2-ch. (each channel driven DIN 1kHz, 4Ω)

THD at rated output power 1 kHz, 8Ω (IHF): <0,3%

THD at 4 x 50 mW, 8Ω, 1 kHz (DIN): <0,2%

Power bandwidth 4 channels driven: 7 Hz - 40 kHz

Frequency response at AUX input DIN: 7 Hz - 25 kHz (+0,5 dB, -1 dB)

Input sensitivity impedance:

Phono: 2,5 mV/50 kΩ

Tape monitor, Tuner, Aux: 150 mV/100 kΩ

Bass control (100 Hz): ±10 dB

Treble control (10 kHz): ±10 dB

CD-4 Demodulator Section

Input sensitivity: 2,5 mV

Input impedance: 100 kΩ

Distortion: 0,07%

Signal-to-noise ratio: >70 dB

Separation 1 kHz: 50 dB (left to right); 30 dB (front to rear)

Frequency response: 20 Hz - 15 kHz

FM Section (87,5 to 108 Hz)


IHF: 10,3 dBf

DIN (26 dB S/N ratio, 40 kHz dev.): 1,2 μV

Capture ratio: 1 dB

Selectivity (±400 kHz): 80 dB

S/N ratio (mono): 70 dB

Image rejection: >85 dB

THD (stereo) 1kHz: <0,4%

Stereo separation 1 kHz (DIN): >40 dB

Subcarrier suppression: 65 dB

MW Section (525 - 1605 kHz)

Sensitivity (IHF): 15 μV/m

Image rejection: >65 dB

IF rejection: >85 dB

S/N ratio: 50 dB

Power consumption: 530 W

Dimensions (W x H x D): 550 x 160 x 440 mm

Weight: 22,4 kg

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