Accidental Peter Green Modification Unmasked - Calling Gahr!!!!

And, to further add to the quandary....you never see Peter Green or Gary Moore with their switch in the middle position...not on any videos that I have seen as of yet anyways...
 
Robert Herndon said:
LOL!!!

Ok...This part keeps puzzling me though. In a single coil, the pole pieces are actually magnets...which is why they pull on the strings as opposed to a humbucker, ehich can be placed much closer to the strings without creating a Wolftone.

In a humbucker - from my study - it appears the pole pieces are just metal and are not - in and of themselves - magnetic in nature until place here the magnet. So, if we rotate the pickup itself 180° we have now changed the North/South arrangement of the pickups from this diagram:

magnetor-71-gif.18128


But as Gahr said, doing that doesn't change anything. However, both coils are essentially the same, are non-magnetic and cannot (in my mind) influence or change the magnet's polarity. So the 'out-of-phase' effect seems to be from the N & S sides of the pickups facing each other - opposite of the diagram shown above - which can be induced by moving the pickup physically 180° of rotation.

But, if what Gahr says is correct, that if you rotate the pickup the pole will switch back to its regular orientation, I cannot see how a passive set of coils and pole pieces can - in any way - influence a switch in the magnet's N & S orientation.

So, let me further postulate...are you saying that when you alter the magnet's N/S position, it causes the path of electrons through the coils to actually change direction, effectively reversing the phase electronically rather than magnetically???
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I think the only way to understand it fully is to do some homework on how an inductor works (a guitar pickup is an inductor). The relationship of magnetic poles to how the coils are wired is what causes the effect, though I am not a great teacher so although I sort of understand it I can't explain it (though I know others here can).

Different types of Inductors, Working And Its Applications
 
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Robert Herndon said:
And, to further add to the quandary....you never see Peter Green or Gary Moore with their switch in the middle position...not on any videos that I have seen as of yet anyways...
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I think you may be implying that in the middle position you wouldn't get any sound due to phase cancellation? But that wouldn't occur because the pickups are located at different positions relative to the vibrating string and therefore induced/influenced by different portions of the energy exerted by the string, so it wouldn't be a 1-to-1 cancellation due to differing harmonics, overtones, signal strength, etc.
 
Right. The position of the pickup along the string length affects the shape of the vibration in the field of each pickup. why bridge and neck pickups sound different.

if each signal was viewed on an o-scope they would not be exactly the same or exactly 180° out / where the waves cross the x axis would not intersect each other, or the x axis (time) at the same time.

The conductor moving - vibrating - in a magnetic field causes current in the windings: push pull, push pull.
Reversing 1 magnet changes the direction of 1 pickup to pull push, pull push, both starting at the same time the string is plucked.
Some but not all of the signal cancels out.
 
Once the magnet touches the pole pieces, they themselves become magnets - or rather they become part of the whole magnetic circuit. It doesn't matter which part of the whole deal is the original magnet. The phase of the pickup is determined by the relationship between the magnet (including pole pieces) and the coils.

In a single coil pickup you have - say - a magnetic north at the top of the pole piece and a south at the bottom. The coil is wrapped around that, and you decide whether it is effectively clockwise or counter-clockwise when you choose which end of the coil is hot.

In a humbucker you have this same thing - but twice. One coil has the north at the top and south at the bottom. The other has the south at the top and the north at the bottom. This puts the two coils out of phase and their signals will cancel. So what you do is swap the hot and cold ends of one of the coils. The signals now add in phase and you have a humbucker. But interference coming in from outside doesn't use the magnets. It creates its own magnetic field which hits both coils equally. But we have just switched one of them round, so the interference gets cancelled - voila, humbucking.
 
DonP said:
Once the magnet touches the pole pieces, they themselves become magnets - or rather they become part of the whole magnetic circuit. It doesn't matter which part of the whole deal is the original magnet. The phase of the pickup is determined by the relationship between the magnet (including pole pieces) and the coils.

In a single coil pickup you have - say - a magnetic north at the top of the pole piece and a south at the bottom. The coil is wrapped around that, and you decide whether it is effectively clockwise or counter-clockwise when you choose which end of the coil is hot.

In a humbucker you have this same thing - but twice. One coil has the north at the top and south at the bottom. The other has the south at the top and the north at the bottom. This puts the two coils out of phase and their signals will cancel. So what you do is swap the hot and cold ends of one of the coils. The signals now add in phase and you have a humbucker. But interference coming in from outside doesn't use the magnets. It creates its own magnetic field which hits both coils equally. But we have just switched one of them round, so the interference gets cancelled - voila, humbucking.
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That helps, Don....Thank you.
 
Most amazing thing for a metal guitarists is how useful the middle position becomes. I literally stay in it because of the chainsaw-like quality to the tone, and I sometimes switch to the bridge for solos as it is a bigger, fatter tone than the middle.

Now I don't play anything 'mellow' or clean, so I cannot comment on the mod from a blues standpoint, but it would seem Gahr has that covered... :-)
 
Robert Herndon said:
Most amazing thing for a metal guitarists is how useful the middle position becomes. I literally stay in it because of the chainsaw-like quality to the tone, and I sometimes switch to the bridge for solos as it is a bigger, fatter tone than the middle.

Now I don't play anything 'mellow' or clean, so I cannot comment on the mod from a blues standpoint, but it would seem Gahr has that covered... :)
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I'll use Peter Green to illustrate the usefulness in a blue setting. Here's "Jumping at Shadows" from the "Live in Boston" album, one of my favorite Peter Green performances. In the beginning he clearly plays in the middle position. Throughout the song he switches pickups and manipulates volume. For instance, at 2:40 he switches to the neck pup and turns the volume full up. Then, at 3:17 he switches back to the middle and stays there for the rest of the song, using the neck volume knob to change the sound several times.

 
Robert Herndon said:
Most amazing thing for a metal guitarists is how useful the middle position becomes. I literally stay in it because of the chainsaw-like quality to the tone, and I sometimes switch to the bridge for solos as it is a bigger, fatter tone than the middle.

Now I don't play anything 'mellow' or clean, so I cannot comment on the mod from a blues standpoint, but it would seem Gahr has that covered... :)
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I like the middle for the slightly nasal quality I get for rhythm. I also like to use the "one knob" trick for certain things.
 
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