Hmm. I didn't find it to be the most responsive of pedals to be honest. My experience of filter pedals is increasingly that they're quite delicate beasts and input level, type of string, playing style can have a big impact upon how they sound....so I sold it. I found the MXR one to be the same to be honest. Yet the Groove Regulator is fantastic, as is the Fwonkbeat. The Engima Q Balls is variable - good on some basses, suspect on others!