How Many Combinations For Humbuckers?

[Nalo1022]

My catalog from Mouser came in a couple days ago adn ive been flipping through it and getting random ideas. Aftr looking through all the switches and once again finding myself trying to draw up rediculous wiring schemes, i started to wonder. How many diffrent wiring combinations are there for a standard 4-conductor humbucker: in-series, out of series, parallel etc how amny total combintaions could you get out of a single humbucker? Granted i know some of the combinatiosn will ofer such subtle diffrences in sounds that you could barely notice the diffrence but im just wandering how many toall possibilities there really are?

[lovekraft]

Looks like twelve total (although several are either useless or nearly identical) - here's the lineup (|| is parallel and <=> is series).

• +A
  
• -A
  
• +B
  
• -B
  
• +A||+B
  
• +A||-B
  
• +A<=>+B
  
• +A<=>-B
  
• -A||+B
  
• -A||-B
  
• -A<=>+B
  
• -A<=>-B
  

[Nalo1022]

Thanks...yes i know that many of them i basically useless but im looking into some very interesting swtiching ideas and i want to know how many total possible combintaions there are just incase i do feel the need to incorporate each one into my ideas lol.

On another note i very a kinda odd question. Would there be any serious issues with having the volume and tone pots, and switces wired a great distance away from the pickups for example say anywhere from 5-10 feet?

[lovekraft]

Unless you're using some kind of active buffering or a transformer system to lower the impedance, you're going to probably lose a lot of high end, and every foot of cable you add is going to raise the noise level somewhat. You migt want to tell us what you have in mind - somebody around here has probably already tried it, and can save you a lot of time and trouble if it's totally unworkable, or at least tell you what to avoid. Like somebody said, there ain't much new under the sun.

[frank falbo]

So long as you used shielded cable, it would be no more signal loss than the equivalent length of guitar cable. So if you had 10' before the vol/tone circuit and 10' after, you should have the same "tone" as with 20' of cable coming right from the guitar. The only difference, if any, would come from the inherant load the vol/tone circuit places on the signal. It would still place the same load, but now it would be doing it AFTER 10' of cable. So the slight treble loss from a vol/tone pot would be applied AFTER the signal was already slightly degraded from 10' of cable. But since the vol/tone load is a result of limiting, as in "no more than 500kohms will pass etc." I don't think it would be any different. Like even when fully up, the pots place a ceiling on the amount of signal that will pass unaltered. Whether that comes after 10' or not shouldn't matter at all.

For a long time, I've wanted to do something like have a volume/blender pedal act as a blend between two humbuckers. Then you could sweep it like a wah pedal, but you would really be sweeping between the bridge and neck pickup, with all the delicious harmonic alterations in between. So I've thought about this a little. It's not like a standard guitar harness "conditions" the signal or somehow makes it "ready" for a cable run.

[JohnH]

Concerning the sounds from a single HB, of the 12 listed above there are 6 different ones, since pairs of combos where both are inverted for phase will sound the same (unless you start combining with another pickup). they are

each single coil

both coils in series, in or out of phase

both coils in parallel, in or out of phase

In a bridge position, the two single coils sound similar but a bit different, in the neck position they sound virtually the same

Coils out of phase make a funky thin sound, not hum cancelling, rather low volume

Parallel in-phase is a bit brighter than series in-phase, and is hum cancelling. I find this the lowest noise setting of all and very useful.

To pick say the best 4 out of the six, Id skip one of the single coil sounds and the parallel out-of-phase. I have a switch arrangement for this here:

http://people.smartchat.net.au/~l_jhewitt/...uits/1H4way.gif

There is another technique also, which is to put a capacitor across one of the coils in a series connected humbucker. Ive not tried this, but it is intended to give a coil cut sound for the high harmonics, keeping the humbucker noise cancelling and deeper tones. Must try it some time!

If however, you are building up to a circuit with 2 HBs, then the other single coil can be useful (reverse phased), to get a hum cancelling out of phase sound between pickups. Theres heaps of posibilities and good/bad sounds! I think that getting hum cancelling and phasing correct is the key to complex guitar circuits, trying to weed out the duff noisey combos and concentrate on the good sounds. (my current switching on my 2Hb guitar has 30 sounds). Let me know if youd like more stuff that i have on phasing and humbucker switching.

[scott from _actual time_]

Concerning the sounds from a single HB, of the 12 listed above there are 6 different ones, since pairs of combos where both are inverted for phase will sound the same...

Coils out of phase make a funky thin sound, not hum cancelling, rather low volume...

all very true...

...in the neck position they sound virtually the same

...but i'd have to strongly disagree with this. i hear very distinct differences in the two different coils of humbuckers in the neck position. it's less pronounced on 24 fret guitars, but it's definately there.

the coil closer to the neck sounds snappier and grittier to me, more strat-like, while the coil closer to the bridge sounds smoother. several of my complicated switching schemes that change all 5 positions of the 5-way switch alternate the different coils of the neck humbucker to get these different sounds.

Edited May 5, 2005 by scott from _actual time_

[Stalefish]

Erm, I actually feel that having a ton of combinations often isn't really worth the effort of worming your way through all the electronics.. A lot of the time, the combinations sound very much similar anyway.. Either that or aren't very usable.. Then you get the problem of finding the sound you want when you want it on stage.. I used to try to get as many combinations out of the pickups but I decided that I'll just stick to series/parallel humbuckers.. Easy to put together and is sonically versatile.. My 2 cents!!

[JohnH]

  i hear very distinct differences in the two different coils of humbuckers in the neck position. 

Thanks ..Thats interesting!...any theories on why that happens? Do you still get that if you use a high fret, so the pickup is right in the middle of the vibrating string? Are the poles of the two coils different (eg one adjusted higher than the other)?

regards

John

[Robert_the_damned]

some humbukers have 'uneven' coils ie. one witth more windings than the other. so that might make SOME differance.

[scott from _actual time_]

  i hear very distinct differences in the two different coils of humbuckers in the neck position. 

Thanks ..Thats interesting!...any theories on why that happens? Do you still get that if you use a high fret, so the pickup is right in the middle of the vibrating string? Are the poles of the two coils different (eg one adjusted higher than the other)?

it happens for the same reason that a humbucker sounds different in the bridge position vs. the neck position -- the tone is different the farther away you move from the bridge. the difference is more subtle when you're comparing two coils in a neck humbucker, right next to each other, and a coil at the bridge vs. a coil at the neck, but it is there. it will happen playing at any fret. of course, playing at the 2nd fret and playing at the 23 sound different, but that's a whole 'nother variable.

the poles of my neck humbuckers are adjusted to the same height. i use mostly DiMarzio neck humbuckers, so the neck coil is screw-head pole pieces and the bridge coil is slugs. as far as i know the two coils are both wound to similar resistance, so any tonal difference from the pole pieces is tiny.

[darren wilson]

My advice would be to try out all these combinations by manually clipping or tying the wires together. Evaluate each one and then design a switching scheme that incorporates the most useful/usable tones.

Having over a dozen options available makes it difficult to switch between them, and chances are, you're only going to end up using two or three of them in the end.

[JohnH]

Darren - thats good advice. Ive also found it useful to solder up a new switch combination and test it for sounds, before doing the serious work of drilling new holes etc. Its easy to unsolder things, and its saved my poor guitar from several permanent disfigurements!

I think everone needs to make their own mind up about number of sounds v switch complexity, and I take your point about having too many. Wouldn't want to suffer brain fade and hit the wrong switches just before the key solo of my next stadium gig....(fades into daydream....)

Concerning differences in single coil sounds, my point about using a high fret is to get the neck pup in exactly the centre of the moving string, and pluck the string there, so each coil gets the same input from the string.

There is another reason why single coils cut from humbuckers may sound different: if one is formed by bypassing the non-active coil while the other has the non-active coil disconnected. In theory, a bypassed coil, with its ends shorted together, can generate currents in itself that cause a magnetic interfereance with the first coil, and maybe damping.

[lovekraft]

In theory, a bypassed coil, with its ends shorted together, can generate currents in itself that cause a magnetic interfereance with the first coil, and maybe damping.

If that (bypassed) coil is shorted to ground or open-circuited, it can't (by definition) generate any current - I agree that there might be some magnetic interaction, but no electrical output is possible. If it isn't either open-circuited or grounded out, it isn't wired correctly.

[Moreau]

so if one was to install a single humbucker at the bridge, and a switch, just one, what would be the 3 or so best wiring combos?

[JohnH]

Lovekraft - Let me explain further what I on about! (appologies if Im not clear enough).

A bypassed coil, although it can't directly send an electrical signal to the output, has currents running just within the coil itself, since the connection from one end of it to the other creates a circuit and generates electricity, drawing energy from the string. Its a similar effect to spinning the spindle of an electric motor, which is harder to do if you short it out because of these induced currents drawing energy.

In the bypassed pickup coil, these currents cause changes in the magnetic field which may reach the other, active, coil, affecting the sound. This affect does not happen in a fully disconnected coil, because there is no circuit for the induced currents.

I have not got to the bottom of whether this effect is significant, hence my interest in tracking it down, because it may affect the way we choose to design switching circuits.

Moreau - with one humbucker and one switch, your options would depend on the switch. It wouldn't be hard to get in-phase series, in-phase parallel and one single coil, I think those are the best three. If you use a 3 pole 4 way switch (could be rotary or lever), the next Id choose would be series out of phase for its super thin sound for strumming.

John

[lovekraft]

...In the bypassed pickup coil, these currents cause changes in the magnetic field...

Those currents are being induced by the changes in the magnetic field caused by its interruption by the vibrating string - I see no way that the currents involved in a shorted coil can possibly generate EMF enough to have any effect on the other coil. I'm not simply trying to be contentious, nor can I state without question that at some level this scenario isn't possible, but if we're going to limit ourselves to audible level signals, I'd have to see some spectrum analyzer evidence that this effect exists to even consider it. But I've been wrong before - if you feel it's worth pursuing, you should do the testing and find out. It wouldn't be hard to set up a test jig, and the results could be quite interesting.

[JohnH]

Lovecraft - my initial expectation matched yours, that the induction effect would not be significant. I have read of it more than once elsewhere however from opinions of guitarists who are also electrical engineers. I like to understand these things to be confident that the circuits that i design are optimised.

So I have now done a test, not alas with a spectrum analyser, just with careful listening through headphones. The design of my guitar is such that I can get access to the wiring through a separate cover plare, without removing the pickups etc. It also has quite a range of settings such that with a jumper lead, I could test this, with two settings as follows:

A - neck pickup, coil 1 connected between ground and output, all other coils disconnected

B - as A, but with neck coil 2 short circuited to itself, (coil 2 was not conneceted to the output)

My results were....no audible difference at all!, so 'myth busted' as far as Im concerned, and in accordance with with your post above. I think thats interesting.

regards

John

[thedoctor]

If the bypassed coil is wound around the same poles as the other coil or is magnetically coupled to the other coil, it becomes a variable choke in effect as the output windings are shorted together. That is basic welder design. Doesn't sound like a very good idea for pickups unless there is some odd tonal value gained. After buying a few cheap guitars to test different setups with, I have found that most people can narrow their preferences down to a managable number of combinations and simpify the wiring greatly! I just leave everything hanging out the back and try stuff with jumpers (ignoring the noise) and write down what they like. Someday I might try making another proto-panel with rotary or DIP switches to ease the pain of trying different setups but not this year.

[JohnH]

If the bypassed coil is wound around the same poles as the other coil or is magnetically coupled to the other coil, it becomes a variable choke in effect as the output windings are shorted together. That is basic welder design. Doesn't sound like a very good idea for pickups unless there is some odd tonal value gained.

Yes, that is the effect i was trying to test. Many circuits for coil cutting a humbucker do so by a bypass switch across one coil, which would create this condition, if it was significant. I could not hear any difference in practice though, so I now believe that bypass switches are OK