Welcome to the 4th part of my ‘Guitar Wiring 101’ series of blogs. If you’ve missed the previous blogs, check them out here: Rowbinet’s Guitar Wiring 101 Series
Just like in a previous blog where I talked about volume and tone controls, pickup selector switches are also not essential, yet they are widely used and accepted as the norm. For example, if you only have a single guitar pickup then you wont really need a selector switch (unless you have a humbucker and want to run the coils in parallel or series at different times).
What Is A Pickup Selector Switch and Why Do I Need One?
It’s simple really, it allows you with the click of a single switch to rewire how your pickups are connected inside your guitar. Some simpler circuits, like a stock Les Paul only have 3 settings. Bridge pickup, bridge and neck pickup in parallel, and the neck pickup. For each pickup in a stock Les Paul there’s only 1 wire being switched which is very simple, yet effective.
Other guitars that incorporate coil tapping (switching out one of the humbuckers coils to allow it to act like a single coil pickup), or series/parallel switching, will usually switch multiples wires at the same time and with this can sometimes bring a little more complex wiring.
This is possible because some pickup selector switches are really several switches in one package, so although the guitarist is only making one switch movement, inside the switch there can be several ‘wafers’ all being switched at the same time. More on wafers later…
Can you show me some examples please?
The most common switches you will likely see are those fitted to the most common types of guitar, such as the Les Paul, Fender Strat, Fender Tele, Ibanez RG, etc. So here are some examples:
On a Les Paul, each of the 2 humbuckers have a ground lead and a hot lead. The ground leads go to the body of one of the pots to be grounded, the bridge hot lead goes to the bridge pickup volume control, and the neck pickup hot lead goes to the neck pickup volume control. the output of those volume controls goes to the 3 way switch, and then the output from the switch goes to the guitars jack socket. The switch is really a 2 way switch with a special setting in the middle. At one side the bridge pickup is live. At the other side the neck pickup is live. In the middle both switch inputs are made live, kind of like bridging both inputs to the switch from both pickups, straight to the output at the same time. See this link for a simple diagram: http://www.seymourduncan.com/pdfs/support/schematics/2h_2v_2t_3w.pdf
On a Fender Strat, the pickups are single coil types, but can still be viewed as pickups with a ground wire and a hot wire. The ground leads all get grounded, while the 3 hot leads go to their respective terminals on the 5 way switch. The switch in position 1, 3 and 5 respectively connects the neck, middle and bridge pickup to the volume control, and the volume control acts as a global volume for all pickups selected. Position 2 and 4 are similar to the Les Paul selector middle position, in that position 2 bridges the seelcted pickups form positions 1 and 3. Likewise position 4 bridges the pickup selections from positions 3 and 5. Another little twist is that the tone controls on a Strat only work for the middle and neck pickups, and they are switched into the circuit by the 5 way switch too. So in some respects the Strat 5 way switch does more than just select pickups. Here’s a simple diagram: http://www.seymourduncan.com/pdfs/support/schematics/3s_1v_2t_5w.pdf
What About More Complex Switching?
See the two images below. The first image is showing you the 2 orange wafers in the Fender Super Switch, and on each wafer you’ll see 2 seperate sets of contacts. Each seperate set of contacts is a seperate switch, and on this super switch there are 4 switches, labelled as A, B, C and D. Below that you can see the connection diagram showing you how the super switch works with the A, B, C and D labels. You may also notice that each switch is a SP5T type of switch, which means Single Pole with 5 Throws, or rather a single wire (the pole) can be joined to any one of 5 other wires (the throws). Some more common switches you will have seen elsewhere are called SPST (Single Pole Single Throw) and DPDT (Double Pole Double Throw), as well as the very common in foot pedals, 3PDT (3 Pole Double Throw). Phew, that’s enough throwing for one day… BUt if you want to know a little more about switching, perhaps if you want to use some seperate switches for coil taps, then check out this link: http://en.wikipedia.org/wiki/Switch
If you need some help with wiring diagrams for your guitar, then head over to Seymour Duncan’s website, for a shed load of wiring diagrams for most guitars. They can be used for non Seymour duncan pickups too (with the wire colour code conversion chart).
Seymour Duncan Wiring Diagrams: http://www.seymourduncan.com/support/wiring-diagrams/
Colour code conversion chart for other pickup makes: http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=color_codes