Here are the guts inside the new S-type guitar I built. HSH pickups with rail humbuckers. Each humbucker is coil tapped (not split) in a somewhat different manner using push pull pots. I made tuned coil taps running one of the coils humbucker coils through an RC network to filter out certain frequencies (high pass filter) from that coil while adding some hum cancelling into the mix. The neck coil is primarily filtered and tapped to sound close to a standard single coil. The RC filter for the bridge pickup is tuned for a more P90-ish sound. Values are 3.9KOhm resistor and 0.1 uF cap for the neck pickup filtering higher frequencies to ground and 3.9KOhm resistor and 0.01 uF cap in the bridge, which filters out even higher frequencies to ground leaving more low end frequencies intact.
Also, the tone controls are set up as Treble and Bass roll-off’s. The controls are set up sort of like what one would think a stereo receiver would have – turned all the way clockwise and all frequencies are intact (full treble and bass). Turn the knobs counter-clockwise and the the high end is rolled off the treble like a typical guitar tone knob, and the amount of bass is cut on the bass knob. Basically the same control circuitry that is on a G&L S-type guitar, which I own.
Below is a picture of the guitar body. Mahogany stained blue (I had to bleach the wood first). Finished with about 20 coats of clear lacquer. I finished the neck with teak oil and it is smooth as a baby’s behind with no stickiness whatsoever.