Pioneer QX-646

Data

General

• Manufacturer: Pioneer
• Model: QX-646

Type: Quadraphonic Receiver

• Years of manufacture: 1973 - 1976
• Made in: Japan
• Color: silver, wooden case walnut
• Power consumption:
• Dimensions: 525 x 149 x 360 mm (WxHxD).
• Weight: 12.3 kg
• Original price approx.: 500 US-$, 2'250 DM

Connections:

• Number of inputs:
  • Phono: 2.5 mV, 100 kOhm
  • AUX: 180 mV, 90 kOhm

Tape: 180 mV, 90 kOhm Coaxial FM antenna connection (75 Ohm)

• • AM- Antenna connection (300 Ohm)
• Number of outputs:
  • 2 x speaker pairs: 1 x front, 1 x rear
  • 1 x headphone output: 6.3 mm jack

Technical data:

Amplifier:

• continuous power: quadrophonic, 20-20 kHz
  • 8 Ohm: 4 x 10 Watt

4 Ohm: 4 x 11 Watt

• music power: quadrophony, 20-20 kHz
  • 8 Ohm:
  • 4 Ohm: 4 x 20 Watt
• Continuous power: Stereo, 20- 20 kHz
  • 8 Ohm:
  • 4 Ohm: 2 x 10 Watt
• Continuous power: Stereo, 1 kHz
  • 8 Ohm: 26 Watt
  • 4 Ohm: 30 Watt
• Total harmonic distortion: 0.1 % at 20- 20'000 Hz, 0.3 % at 1 Watt, 8 Ohm
• Attenuation factor:
• Frequency response: 10 - 100,000 Hz ± 3 dB
• Power bandwidth: 15 - 20'000 Hz
• Signal-to-noise ratio:
  • Phono: 70 dB

Line: 90 dB

• Tone control: yes
  • Bass: + 13 dB, - 12.5 dB at 100 Hz
  • Treble: + 11.5 dB, - 8.5 dB at 10 kHz
• Loudness: yes
• High Filter: no
• Low Filter (Subsonic): no

CD-4 demodulator part:

• Input sensitivity: 2.5 mV
• Input impedance: 100 kOhm
• Distortion factor: 0,07
• Signal-to-noise ratio: > 70 dB
• Channel separation at 1 kHz:
  • Left to Right: 50 dB

front to rear: 30 dB

• Frequency range: 20 - 15'000 Hz

Tuner:

• Reception: FM, AM
• Frequencies:
  • FM: 88 - 108 MHz
  • MW: 535 - 1600 kHz
• Input sensitivity:
  • FM: 2.2 µV
  • MW: 15 µV
• Frequency response: 20 - 15'000 Hz
• Distortion factor FM: < 0,8 %
• Signalrauschabstand:
  • UKW: 65 dB
  • AM: 50 dB
• Stereo-Kanaltrennung: >40 dB at 1 kHz
• Selectivity:
  • FM: 60 dB
  • MW: > 25 dB
• Co-wave selection: 1.0 dB
• Spurious wave selection: > 35 dB
• Image frequency attenuation:
  • FM: > 50 dB

MW: > 45 dB IF attenuation:

• • FM: > 90 dB
  • MW: > 55 dB
• AM suppression: 65 dB

Special Features

• Equipped with all quadraphonic systems:
  • CD-4

SQ Decoder

• • Regular Matrix
• Quadro level meter
• Connection for Dolby adapter
• FM Muting
• Bass / Tweeter control V + H separately

Remarks

• All Pioneer Quadro Receivers at a glance:
  • Pioneer QX-646
  • Pioneer QX-747
  • Pioneer QX-747 A
  • Pioneer QX-949
  • Pioneer QX-949 A
  • Pioneer QX-4000
  • Pioneer QX-8000
  • Pioneer QX-8000 A
  • Pioneer QX-9900

• Introduction Kenwood 4-channel playback technology

Pictures

• Extract from brochure: Pioneer QX-646

• Extract from brochure: Pioneer QX-646

• Extract from brochure: Pioneer QX-646, QX-747, QX-949

Reports

• Review of the Pioneer QX-747 by "Hifi Studio": [1]

• Report at "Hifi Museum" [=quadro]

Links

• External link Pioneer catalogue on "Hifi Archive": [2]</0,8>