ROG Flipster Question

[Vitrolin]

Hi i Build the Flipster, and it worked right from the start, everything perfekt, well almost i wired the bass pot bakcwards, but hey a slight detail.
i made it almost to ROG Specs, diferences:
5M6 pulldown resistor is replaced by 4M7 & 820k in series
And in the tonestack 120K replaced by 180K oand the 4n7 cap by 3n3
i´m feeding it 9v and the drain voltages are 4,5v-5v and all q´s are j201s.
well the questions:
i find it a bit poor in the treble so i was thinking about putting a switch that connects tho master pot between the 22n cap and the double lowpass filter or maybe between the two filters, i wonder if this may create a higpass filter 22n/2000K?
second question:
i would like it have a bit more overdrive, it barely overdrives when maxed at the moment, its more like a booster. would it help if i fed it 12v? or changed the drain voltages to say around 7v? or maybe changing the j201 for some other jfets, if then all or some of them?
i have the following jfets:
mpf106
2n5458
mpf102
i hope some one could enlighten theese issues for me.

[Ripthorn]

For overdrive, you would want to bias your jfets a little low, I think.  The more voltage you feed (say 12V) will increase clean headroom.

[Vitrolin]

oh, and another little question, it has a pretty loud swicth pop, how could i eliminate this?