Treble bleed cap value calculation?

[12AX7]

Is there a way to calculate what value cap to use as a bleed on a volume control in a given circuit in order that the frequency curve remains as unchanged as possible throughout it's range? Also, when using a resistor in parallel to it to help keep the balance of lows from dipping, would you use a different value depending on the pot value? In guitars for exampl (tho i'm talking amp volume here) they always cite a 220k resistor, yet i never see them mention any other value even tho as many people use 500k pots as 250k.

[PRR]

? Is there a way to calculate what value cap to use as a bleed on a volume control in a given circuit in order that the frequency curve remains as unchanged as possible throughout it's range?

Yes.

But do you want to do tedious math or get on with life? Tack 50pF 100pF 200pF in place and listen.