Here is a circuit for 3 single coils, operated by 3 mini toggle-switches. It looks a bit strange, but its simple to operate, really just an on/off switch for each pickup. The extra poles ensure that all of the possible two-pickup combinations are hum-cancelling. This is done by making the middle pickup switch, when set to ‘off’, reverse the phase of the bridge pickup. So this provides:
middle, bridge or neck – single coils middle/neck and middle/bridge – parallel in phase – hum cancelling neck/bridge – parallel out-of-phase – hum cancelling neck/middle/bridge – all in phase – not quite hum cancelling but less hum than single coil
The off/off/off position seemed a bit pointless, so I added extra poles to each switch to make this position middle/bridge – series in-phase, also hum-cancelling. I believe this is Brian Mays favourite sound, for all you long haired curly people. The switches are shown in this position.
So in all, there are 8 switch positions and 8 good sounds, with no duff ones.
On the diagram, ‘+’ indicates the finish of each coil, relating to the phase of the sound. The middle pickup is reverse wound. Colours relate the switches to the relevant pickups. Volume and tone pots could be added to taste (but they are not very interesting).
I haven’t asked any questions, but I’d be really interested in any comments on it, or whether other folk like to look at this sort of stuff.
John H That's a lot of extra switch poles. I can't exactly tell what the switch poles at the bridge pickup are doing. Which switch(es) are they connected to? As you probably know, when showing components that are "ganged" but seperated in a diagram, you should connect those with a dashed line. I don't know if you've seen my diagram at: www.1728.com/guitar2.htm It gives a lot of tone choices with only 5 switches. If you don't want the phasing option, you can eliminate one switch and only lose 1 sound. Anyway, my setup only requires 3 SPST switches and 1 DPDT switch. Still, I would be interested in how that circuit works if you'd show how that circuitry near the bridge works.
Oh and I like middle and bridge in series also. I like to switch from middle and bridge in parallel ("Sultans of Swing" sound) to middle and bridge in series (higher output, fuller sound - like a humbucker).
Wolf - I like your 5 switch circuit, very versatile. Mine has only 3 switches, so Im not going for as many tones, but trying to keep it very simple to operate, and avoid all possibility of settings with bad hum, or duff sounds. The 3 switches are two DPDT and one 4PDT, available as standard mini toggles which mount in a 1/4" hole.
The circuit was harder to draw than it would be to use. I usually follow the practice of the dashed lines to indicate ganging, but it this case it gets too tangled! The ganging is indicated by the colours, so the 4PDT, which conceptually can be called 'middle on/off', is all of the green poles on the diagram etc
The two green poles on the right (which are actually part of the middle switch) reverse the phase of the bridge pickup if the middle pup is 'off'. Oddball? the reason is that with simple on/off switching (imagine a simple parallel switching where each coil had an SPST), the middle/bridge combination would be hum cancelling, but the neck/bridge combo would be hum adding. So the reversal of the bridge, if it is not being combined with the middle, sets it up for a funky out-of-phase and hum cancelling combo with the neck!
All of that is hidden from the user, who just switches the pups on and off in the combos that they want, the phase change happens behind the scenes, to keep all the main combo setting hum cancelling.
The series setting adds one extra pole to each switch, and conncets the bridge and middle into a series chain, but breaks that chain unless all switches are off