PiMaxC
New member
When I went to college my grandfather gave me his old Panasonic quadraphonic 8-track player/integrated receiver, and I've enjoyed it on and off through the years, but I recently dusted it off as one of my quarantine projects has been setting up a HiFi system and restoring some speakers, but I noticed that I'm having some odd behavior from this receiver and I was hoping someone could help me pinpoint the issue.
I can't seem to use both front or rear channels at once, only one of the two channels from each stereo pair will work properly at a time. Now I can run the front right and rear left to get around that, but I'd love to be able to experience it in it's full quad glory. When I have both channels attached to the same stereo pair one of the channels will only play at the correct amplification level only within a small sweet spot on the volume slider, every other spot it sounds almost like there's no pre-amplification. I've done the easy thing of spraying down the posts, sliders, and switches with contact cleaner and giving them a few passes through their range to try and clear off the 40+ year old gunk, but no dice. I've also opened it up and looked for any tell tale signs of capacitor plague or shiny spots on the ICs, but it looks pristine in there, he really took great care of it.
I have tested this by using a aux cable and the built in FM tuner. I tested each input and output separately as well as together and the behavior remains the same regardless of if the source is internal or external so I think it is unlikely an issue with the source or input jacks. I did realize that the back panel calls for 16(!) Ohm speakers, but I'm not sure if they mean the whole system adds up to 16 Ohms with 8 at each channel, or each speaker is meant to be 16. I can't seem to find a service or user manual online without paying like $20 to one of the usual suspects. I have a DMM at home for troubleshooting, but if I need it I can bring my receiver into work to use an oscilloscope.
I can't seem to use both front or rear channels at once, only one of the two channels from each stereo pair will work properly at a time. Now I can run the front right and rear left to get around that, but I'd love to be able to experience it in it's full quad glory. When I have both channels attached to the same stereo pair one of the channels will only play at the correct amplification level only within a small sweet spot on the volume slider, every other spot it sounds almost like there's no pre-amplification. I've done the easy thing of spraying down the posts, sliders, and switches with contact cleaner and giving them a few passes through their range to try and clear off the 40+ year old gunk, but no dice. I've also opened it up and looked for any tell tale signs of capacitor plague or shiny spots on the ICs, but it looks pristine in there, he really took great care of it.
I have tested this by using a aux cable and the built in FM tuner. I tested each input and output separately as well as together and the behavior remains the same regardless of if the source is internal or external so I think it is unlikely an issue with the source or input jacks. I did realize that the back panel calls for 16(!) Ohm speakers, but I'm not sure if they mean the whole system adds up to 16 Ohms with 8 at each channel, or each speaker is meant to be 16. I can't seem to find a service or user manual online without paying like $20 to one of the usual suspects. I have a DMM at home for troubleshooting, but if I need it I can bring my receiver into work to use an oscilloscope.
