Here is one of Pioneer’s classic Quad’s, or 4 channel, offerings the Pioneer QX-8000. The QX-8000 supplied 20 watts per channel into four channels at 8 ohms. It weighs just over 34 pounds. It also featured:

• Low and high filters
• Loudness on/off
• FM muting on/off
• Speakers front on/off rear on/off
• Two bass/treble controls
• Phones outputs front and rear
• Tuning meter
• AC Outlet Switched and Unswitched
• Phono 1 + 2
• Aux 1 + 2
• Speakers A Front  Rear
• FM Antenna 75 Ohm + 300 Ohm
• AM Antenna
• Tape Monitor 1 Out/In
• Tape Monitor 2 Out/In

 

The Pioneer QX-8000 was manufactured from around 1974 up until 1976. It’s parts layout from the top view looks like this:

 

 

The Pioneer QX-8000 isn’t in high demand so its price is still reasonable. They sell from around $150.00 up to $250.00.