All Things Analog

All Things Analog

Pioneer QX-949 Quadaphonic Receiver



Pioneer QX-949 Front Panel

Description

The QX-949 is Pioneer's ultimate four channel FM/MW stereo receiver, featuring all present quadraphonic systems, CD-4, SQ and regular matrix. The unique power boosting circuit converts the large 4-channel power output to even greater 2-channel power. Other features include 3 pairs of tape terminals, 4 pairs of speaker systems, 2 pairs of phono terminals, high and low filters and a Dolby NR adapter switch.

When this receiver was introduced in 1974 it was Pioneer's top of the line receiver for that year. This particular model has all of the popular forms of quadraphonic decoding built directly into the receiver. This meant that there was no need to purchase an external demodulator or decoder.

The output of the receiver is rated at 40 WPC when operating in quad mode, however when the block on the back is changed into 2-channel mode it is capable of putting out 60 WPC. This unit can handle 4 individual pairs of speakers (two in the back and two in the front).

In addition, on the back there are inputs for three tape decks, two turn tables, and an auxillary source. Also, ther is a 4 channel MPX decoder output on the rear of the unit in anticipation of the 4 channel FM broadcasts which would be coming soon.

The tuner usue a 4-gang variable capacitor and phase linear ceramic filters which give it great sensitivity and exceptional selectivity.

One of the thing which sets this reciever apart from the rest is that it has a unique 4-channel 'oscilloscope'. In reality, this is simply a set of four VU meters behind a shadow mask to give a similar effect for a much lower price.

When new, this unit was priced around $750.00 in 2019, that would be the equivalent of spending ~$3,500.00!

Specifications

  • Tuning range: FM, MW
  • Power output: 60W/ch (stereo), 40W/ch into 8Ω (quadraphonic)
  • Frequency response: 7Hz to 25kHz
  • 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
  • Total harmonic distortion: 0.3%
  • Damping factor: 35
  • Input sensitivity: 2.5mV (MM), 150mV (line)
  • Signal to noise ratio: 70dB (MM), 90dB (line)
  • Output: 150mV (line)
  • Speaker load impedance: 4Ω to 16Ω
  • Semiconductors: 14 x FET, 7 x IC, 118 x transistors, 69 x diodes
  • Dimensions: 550 x 160 x 440mm
  • Weight: 22.4kg
  • Year: 1974
  • Downloads (free)

  • Owners Manual
  • Service Manual
  • Schematic