Puncher:Do I take it that the rotary "knob" of the MCP6500 doesn't count??
I specifically excluded them
Under the hood, it's nothing more than a glorified up-down rocker switch (a clever idea making one look like that, unfortunately the feel for volume control isn't too great).
Anyway, Jeff and Steve pointed out the product line starting from BM1900. I forgot about those, since I've never seen one in flesh. If the preset wheel in BM3300 actually turns something instead of just pulsing an IC or whatnot, I think it is the winner (-> 1989).
I actually came up with this after operating my Beogram 6000 and wondering what kind of a knob (it's missing) the power switch in the rear should have...