We've had a lot of recent discussion concerning the G&L Hi-Pass/Lo-Pass tone circuit, so I thought I'd post the original schematic of one of the G&L models, the S-500. This is re-posted from a post by ChrisK, and I include his (quoted) comments here as well.
Also note the switching scheme, with the "neck on" switch plus the standard five-way toggle.
The tone controls on a Strat are not band pass/reject circuits, but low-pass, high-cut only circuits.
Only an active electronics module (and a battery) will give a true equalizer control system.
However, a system like that used by G&L works as a low-pass on one knob and a high-pass on the other.
Note that C3 is not needed and only reduces the high frequencies. Removing it will make the guitar sound brighter.
VR3 and C4 is the traditional low-pass, high-cut tone circuit from a Strat.
VR1 and C1 is the low-cut, high-pass circuit. Note that C1 is 0.002 uF and not 0.022 like C4.
C2 is a traditional high frequency bypass that helps preserve the high frequencies when the volume control (VR2) is turned down.