Dual Ruby questions

[psiico]

I'm either about to learn something new here or discover I'm an idiot and have been doing something very wrong.  I've been breadboarding a dual Ruby/Little Gem MkII for a couple of days now, experimenting with different input boosters, gain pots or diode clippers in a preamp stage for different sounds, trying to find what I like.  Part of all this fun and games is a tone stack but so far everything I tried either didn't work at all or acted more like a volume then a tone control.

Here's where I might learn something:

I've only tried building tone circuits that involve shunting frequencies to ground, does the reason they aren't working have anything to do with it being a DUAL Ruby and ground is going to input -  on one chip and input + on the other?  So when I shunt frequencies to ground I'm really just shunting them to the inverted input of the other chip and nothing changes?  Am I correct in thinking I'd be better off with opamps and using 1/2v for shunting the tone controls like in the Pocket Rocket schematic that's out there?  Or is it just that I'm an idiot and I've somehow managed to build a dozen different tone circuits completely wrong?

On a side note, how do you install a headphone jack on a dual Ruby?  I know how to do it for a single but that didn't work.