Simple tone control (low-pass) for Mosfet Boost? (I need a bass booster)

[Xavier]

I want to use the Mosfet Boost in order to give my EMG81 equipped guitar a little more bass. SInce I really like the Mosfet Boost, i was thinking of tacking a simple 220R/.22uF network before the out put cap. I want to make kind of a "bass booster" by cutting the treble frequencies of the Mosfet booster off

What pot value should I use? Are these RC values OK? (taken from a TS9 schematic)