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Question about 7C tone rotary switches

Looking for an answer to something that has puzzled me for a while about the Marantz 7 preamp stepped tone controls. In particular, the schematic shows the bass rotary to be a twin deck switch and treble rotary to be a single deck. Photos of the treble unit shows it has a phenolic disc at its rear connected via standoffs but the disc is used for terminating the other ends of the RC components only and is not a contacts deck.
Photos of the bass rotary switch shows it to also only have a phenolic termination disc at its rear and I'm not seeing a switch deck. All the photos I've seen show a cutout hole at the rear disc of both treble and bass rotary switches.
I would love to hear from someone who can look at these switches and let me know if I'm just not seeing the second switch deck of the bass tone controls or if the actual switches do not match the schematic?


  • 7C tonepots.PNG
    7C tonepots.PNG
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  • 7C bass tonepots.jpg
    7C bass tonepots.jpg
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