12. Single Coil Wiring
Standard Wiring
Since using single coils in parallel doesn't really make sense most guitars are delivered from the factory with serially connected single coils. The end of the 'top' coil (B) is connected to the end of the 'bottom' one (D) and soldered. Then lead cable (A) of coil 1 is connected to the point where the "hot cable" of the original pickup was connected. The lead cable (C) of coil 2, together with the non-insulated ground cable, is soldered to the ground point (usually the back of a pot housing).
If a virtual single coil sounds "out of phase" when working in parallel with another pickup then then cables must be switched. The hot cable (A) is grounded and cable C is soldered to the hot spot.
Single Coil Switching
Virtual single coils can also be operated in real single-coil mode. If the coil closest to the strings remains sharp, then the sound produced is louder and has more treble. Using the lower coil makes no sense since it would be too quiet. Something to note though is that the hum compensation you usually get from virtual single coils is lost when it is used as a true single coil.
To switch one of the coils off you can use both 2-pole changeover switches (DPDT) as well as simple 1-pole changeover switches (SPDT) or push-pull potentiometers. The sketch shows the wiring of a SPDT switch:
A is the hot output. C and the free ground are soldered together then ground. Now it gets tricky (and exciting). Remove the insulation of the factory soldered connection from cables B and D and solder an additional cable (!!!) in place. Then you'll need to re-isolate them all. This new cable serves as a coil split and is soldered to the split switch.
If you use one side of a 2-pole switch (DPDT mini switch), the other side can be used for the single coil management of a second pickup. The wiring looks like this:
Again, C and the bare ground wire go to ground. The two A's are the hot outputs.
Phase-Switcher
As mentioned, phase-switching is only possible on a guitar with two pickups that are active at the same time (and with roughly the same volume level). You only need to connect one of the two pickups needs to the phase switch. Doesn't matter which one!
The out of phase wiring of a 2-pole switch (DPDT) looks like this.
