Im currently working on an Ibanez RM-80, which, to my pleasure, adds nice saturating/overdriving, routing flexibility and general processing to my drum sounds!
The mixer has, instead of available low-cuts on each channel, one master low-cut filter for the left and right channel. Whereas this lowcut works at -3dBm at 100hz and sounds nice, I could imagine various advantages of having it at variable frequencies, given that the Bass EQ already sits at 100hz with options of +/- 15dB.
Therefore my question is, if it is possible to add either a Potentiometer or CV-In to alter the cutoff-frequency of a classic butterworth high-pass filter on both channels.
This is the exact schematics of the filter in question 
I would dearly appreciate any hints and help