tube amp drive control with 2-gang pot?

Can anyone think of a way a 2-gang pot could be used to control the signal driving a tube "color" stage from clean to overdriven, while providing simultaneous compensation of the output?  The goal is to provide an essentially similar overall output volume throughout the control's range, just the distortion character changes.

Essentially, the signal comes in one gang configured in a normal fashion and it goes out through a second gang connected in reverse.  I know I'd need to at least put a resistor between ground and the typically-grounded lug to keep the signal from being attenuated to infinity at both extremes, but am at a loss beyond that.  What kind of taper would be needed on those pots?  Do non-custom pots like that exist or could they be created from stock items with additional resistors?

I know I could accomplish this with a 2-pole rotary switch with hand selected resistors, but would rather this be a continuous control rather than discrete steps.

Any ideas?

Thanks!

-Bob

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PRR said:

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Click to expand...

Thanks PRR. 

Oh yeah--takes advantage of 0=1 (feedback ohms to gain)  I guess I never considered that because I've had bad experiences with setting gain like that with a pot, but probably because I used the wrong (read old) pot that intermittently opened up resulting in a scratchy (or worse) control.

What type of pot (and taper) would you recommend for this?

I'll probably insert a DRV134 before the {?} stage and an INA134 as the buffer you show, as the {?}* is balanced in and out.

Thanks

-Bob

* is a low power adaptation of the Leslie 122 amp circuit that turned out sounding really sweet when you hit the input really hot.