balance slider

Restoring a Marantz 2325, and the Balance Slider has no left-right separation. The volume is the same level except for the middle position, which is slightly louder. I tested with headphones on and with external speakers, and in both cases moving the balance slider potentiometer from left to...

I have a 3200 with a broken balance slider pot. I tried to get one off the bay but it isn't working as a balance pot should (it increases the signal when you go to either side, when it should keep it the same) so I don't think this is a proper balance slider. Do you know where I could find a...