Just to make sure I'm doing this right... if I want to keep the original HP>LP series intact, I keep the blue link and omit the switch, right? I'm not too experienced reading schematics and layouts.
Thanks for the layout! I have built this as well and it sounds really good. I added an LPB1 on the output as a volume control. The high pass filter on guitar with the boost provides a range of awesome sounds. Very worth while!