Magnet Flip vs. Wiring out of Phase

[JGundry]

I know. Not another Peter Green out of phase thread. Well this is really not about the middle out of phase tone so don't turn the channel yet.

Here is the short version. And if I am just too blind to have noticed this mentioned before forgive me. Anyway I noticed that wiring the neck pickup out of phase makes a big difference in the tone of the neck pickup when the selector switch is set only for the neck pickup. With the neck pickup wired out of phase it you get a much clearer and acoustic low end almost devoid of mud with an 8.2K neck pickup with 42AWG PE. Why? Having spent no real time trying to figure it out I assume it must have something to do with changing the signal path to the volume and tone pots when using 50's wiring. Anyway it is pretty pronounced.

Reverse winding or wiring out of phase sounds different in the middle position because of the altered tone of the neck pickup IMO. I tried every imaginable combination in my gutted Les Paul that I can swap pups in super quick and there is no question there is a tonal change in the neck pickup that also effects both out of phase and regular middle position tones. If you wire the neck pickup out of phase and flip the neck pickup to get a "normal" middle position tone you still retain the clearer, more acoustic, mud free neck tone and the middle position becomes more chimey as well. I think is very good tweak for higher output neck pickups even if you don't want a Peter Green out of phase middle tone.

Anyone else have experience with this? I think Spence and others have wired out of phase to get Peter Green tones. But I don't recall anyone mentioning the changed neck tone due to out of phase wiring which is where I think the real tonal change is. I tried it with 42 PE and 42 heavy Formvar and the heavy Formvar muddied the low end to the point that the increased low end clarity was mostly lost. But with 42 PE it was a pronounced change for the better.

[madialex]

My theory is this: it is possible that the bridge and neck being out of phase with each other magnetically although far apart from each other, I think it could be that there is a small amount of magnetic cancellation going on with each string causing this acoustic thing to happen...... Just my theory and in this mind it's no telling what might pop out:D

[black_labb]

so you're saying that wiring the pickups out of phase by swapping th hot and ground leads gives a clearer sound when playing with the neck pup only?

the only explanation i can think of is having the winding start at the middle vs starting at the outside of the coil.

[JGundry]

so you're saying that wiring the pickups out of phase by swapping th hot and ground leads gives a clearer sound when playing with the neck pup only?

the only explanation i can think of is having the winding start at the middle vs starting at the outside of the coil.

You can either swap the hot lead with the ground or you can reverse wind it. I tried it both ways and the effect is the same. Since the start is at the inside of the coil with a reverse wind this explanation does not hold up.

[black_labb]

interesting. whats your explanation?

[JGundry]

I will try madialex's explaination by pulling the bridge pickup out but I suspect the magnetic pull explanation is not it either. I have my guitar wired for 50's style wiring and have only tested it with that. I suspect that it has something to do with running the former ground through the pot and having previous hot go directly to ground. Maybe some sort of bleed, loss, gain or phase cancellation relationship changes by doing this. Just an assumption though.

[David Schwab]

My theory is this: it is possible that the bridge and neck being out of phase with each other magnetically although far apart from each other, I think it could be that there is a small amount of magnetic cancellation going on with each string causing this acoustic thing to happen...... Just my theory and in this mind it's no telling what might pop out:D

If you are talking about humbuckers, then one coil from each is ALWAYS magnetically opposite with one coil on the other pickup.

Think about it... each pickup has a North coil and a South coil, plus the two coils are wired electrically out-of-phase. The reason they don't sound out-of-phase with the other pickup is because you are hearing a composite signal from the pickup's two coils.

So reversing a magnet is the same as either wiring the pickup in reverse or winding it that way because you are dealing with the in-phase composite signal of the two coils.

The whole reason a humbucker works is because of reversing the magnet on each coils makes them out-of-phase, and then wiring them out makes them in again.

So my answer to the original question is it doesn't matter, it's exactly the same. Flip the magnet, or reverse the wiring. Even winding the coils clockwise or counterclockwise (anticlockwise for you Brits) is exactly the same as wiring them in reverse. it's just more work for no gain.

I've never heard a difference and I tried all this stuff years ago.

[JGundry]

If you are talking about humbuckers, then one coil from each is ALWAYS magnetically opposite with one coil on the other pickup.

Think about it... each pickup has a North coil and a South coil, plus the two coils are wired electrically out-of-phase. The reason they don't sound out-of-phase with the other pickup is because you are hearing a composite signal from the pickup's two coils.

So reversing a magnet is the same as either wiring the pickup in reverse or winding it that way because you are dealing with the in-phase composite signal of the two coils.

The whole reason a humbucker works is because of reversing the magnet on each coils makes them out-of-phase, and then wiring them out makes them in again.

So my answer to the original question is it doesn't matter, it's exactly the same. Flip the magnet, or reverse the wiring. Even winding the coils clockwise or counterclockwise (anticlockwise for you Brits) is exactly the same as wiring them in reverse. it's just more work for no gain.

I've never heard a difference and I tried all this stuff years ago.

I'll record a sound clip with the same neck pickup played alone wired in phase and wired out of phase. In theory there should be no difference but you can hear it for sure. I was of the same mind but swapping the hot and ground changes the tone of the neck pickup with 50's wiring.

[David Schwab]

I used to be able to hear the difference with a phase flip (I might still, but my hearing is not as good, plus tinnitus, and I just haven't tried it), but it was such a subtle difference that you couldn't even describe it.

How is the pickup wired? Is it 4 conductor cable, or coax? I think there might be something else going on besides the phase/magnet flip.

Try wiring the pickup up with each coil going to it's own 2 conductor + shield coax cable. Also before you flip the magnet, try running a magnet across the strings over where the pickup would be (without the pickup in there) to make sure there's not some residual magnetism left in the strings that might be causing a tonal change with the new magnet orientation.

Back in the old Peter green thread I had wondered if there might be something going on because of each coil in the pickup having its own sound (screw v. slug) but unless one pole of the magnet is weaker than the other, I don't see how flipping the magnet would alter the tone of the pickup.

It could be a situation whereas you are getting more parasitic capacitance with the pickup wired one way and not the other, and that of course has to do with other factors and not the phase flip.

But I am open minded, and I'm curious to hear the clips. :)

[JGundry]

Okay. I just fiddled with it some more. If I take the bridge pickup out of the guitar the difference is still there. If I unhook the bridge pickup the effect is still there. If I flip the neck pickup around the effect is still there. I've tried it with a reverse wound neck pickup and a regular wound neck pickup both done on the Leesona with the same wire and number of turns and the effect is still there on both. When the hot and ground are swapped on a regular wound humbucker or when it is reverse wound the tone is clearer, cleaner and more acoustic.

My test guitar and the pickups are wired with coax. I use alligator clips to hook the pickups up so changing the hot and ground is easy. I cut a hole through the guitar for each pickup so the strings don't need to come off.

[Rosewood]

Is there a difference in noise also?

[David Schwab]

Okay. I just fiddled with it some more. If I take the bridge pickup out of the guitar the difference is still there. If I unhook the bridge pickup the effect is still there. If I flip the neck pickup around the effect is still there. I've tried it with a reverse wound neck pickup and a regular wound neck pickup both done on the Leesona with the same wire and number of turns and the effect is still there on both. When the hot and ground are swapped on a regular wound humbucker or when it is reverse wound the tone is clearer, cleaner and more acoustic.

But swapped from what? What defines one way or the other? And what are you playing it through? Have you tried a different amp? They do put phase switches on acoustic guitars to prevent feedback, and the effect works on electrics too. So if you plug it into something with headphones instead of a loudspeaker, do you still hear it?

My test guitar and the pickups are wired with coax. I use alligator clips to hook the pickups up so changing the hot and ground is easy. I cut a hole through the guitar for each pickup so the strings don't need to come off.

2 conductor coax? You are hooking the shield up to hot? Once again, I'm not following.

[SkinnyWire]

Well, that could be a "useful" effect for sure. I wonder if it has something to do with the amount of ground plane, for lack of a better way to put it, or the possible interaction of the frame. In the "normal" configuration, is developed across the coil impedance to ground which is generally the metal frame. By "flipping" the connections, the metal frame is now part of the signal path to ground. It's not magnetically conductive beyond eddy currents but it is electrically conductive and could create a field that "impacts" that which is generated in the coil wires? Either that, or simply a capacitive effect of some sort?

Can you check the output signal with a scope to see if the output level is impacted in any way by swapping the connections? Might be interesting if you could associate a measurable electrical impact with the perceived audible impact.

[JGundry]

Okay here are the sound clips. If your computer has decent speakers I think you should hear the difference. The amp is a Matchless Lightning clone. The neck pickup is 8.2K wound with 42PE on my Leesona 102 with an A5 magnet slightly degaussed. I did nothing other than swap the alligator clips to reverse the outer ground braid and the inner conductor before they get to the volume pot . The guitar is wired for 50's wiring with regular vintage style braided cable in the guitar and on the pickups. This clip is just the neck pickup (toggle switch up).

Here is the first clip with normal wiring.
http://gundrymedia.typepad.com/throbak_audio_clips/files/neck_paf_in_phase_1.mp3

Here is the second clip with the braided ground and the inner conductor switched (this would give the out of phase middle tone).
http://gundrymedia.typepad.com/throbak_audio_clips/files/neck_paf_out_of_phase_1.mp3

I bumped the volume up on the second clip by less than 1 db because the volume seems to drop a hair wired this way. But other than that this is the straight recording with my Edirol R-09.

With regular wiring, which is the first clip, the perception while playing is low end mud, a little more output and more distortion. When switching the ground with the inner conductor, second clip, the perception while playing is slightly lower output, increased low end clarity and less distortion, low notes suddenly have a sort of piano quality to them. Also rolling back the volume pot with regular wiring will not duplicate the tone of the second clip.

[David Schwab]

This has nothing to do with the pickup being out of phase. If you want to test that, you need a balanced output by using 4 conductor cable, or at least two conductors and a shield.

I think it's a capacitance effect by having all the metal parts in the pickup hot.

Of course you are going to get more noise too.

[JGundry]

This has nothing to do with the pickup being out of phase. If you want to test that, you need a balanced output by using 4 conductor cable, or at least two conductors and a shield.

I think it's a capacitance effect by having all the metal parts in the pickup hot.

Of course you are going to get more noise too.

The same thing happens when you reverse wind the pickup. In fact the pickup in this clip was reverse wound. So it can't be a capacitance effect because the ground is correct for the second clip. I tried it with a normal wound pickup and the effect is the same when you switch the hot and ground. I probably just made this very confusing but really it's simple. Reverse wind or change the hot and ground before the pot and you get the clearer tone of the second clip.

Interestingly if you flip the neck pickup around ala Peter Green the effect is more pronounced. I don't think it is due to coil offset because the slug coil is only slightly hotter on this pickup.

[Possum]

I had a thought, wow....
Measure the gauss on the magnet and then at the poles. If one is noticeably stronger, I mean if your magnet is significantly stronger on one pole, maybe thats what you're hearing, possible. On favorie early patent both screw poles and slug poles have nearly the same gauss at pole tops. If this becomes unbalanced then flipping the magnet would favor the stronger gauss side.....maybe....

[David Schwab]

I have put phase switches on many guitars, and basses too, starting back in 1970, and I get no difference in tone when it's reversed. These have always had the proper wiring to do it though, not making the shield hot. You can't do phase reversal correctly on a 2 conductor coax.

Even my Fender Mustang sound the same when you reverse one pickup. It has a phase switch for each pickup.

I don't have any guitars wired up for phase reversal at the moment, but I'd be happy to wire one up and record it.

Obviously something is going on there.

Now when you say it's reverse wound, you mean both coils? So you are swapping it out with a non reverse wound pickup to do the A/B test? Or are you still switching the hot and ground? If you are still making the metal parts hot, that doesn't count. You just introduced all that stuff as part of the coils.

First thing is dump the braided coax and wire up a 4 conductor cable, and then try switching the output wires.

[David Schwab]

OK, here's my test. The only guitar I had setup where I could do a proper phase reversal (i.e., multi conductor shielded cable) is my set neck Tele with a Lawrence L-250 at the neck.

So I unsoldered the pickup from the 5-way switch, and used a 1/4" jack with short leads and alligator clips. It bypassed the volume and tone controls.

This was plugged into the "Guitar (Hi-Z)" jack on my Roland digital mixer, which was set up with a clean twin amp patch. This went via S/PDIF to my Mac, and into Spark XL, which is a stereo audio editor.

I played a phrase, stopped and reversed the two wires to the alligator clips, and played the phrase again. I thin edited out the long pause when I was switching the wires.

Phase test (http://www.sgd-lutherie.com/media/phase_test.mp3)

Clearly I'm not getting the results you got. I really think it's because you have all the metal parts of the pickup hot.

So the question is what's going on with your pickup. You said you wound some in reverse. I assume when you don't switch the wires around they sound just like the pickups not wound in reverse. So it's not phase, it's the way you are switching the wires. Try using 4 conductor cable, and I bet it will sound as much the same as mine did.

This is why people flip the magnet. It's easier than unsoldering the hook up wires to a 2 conductor coax. If you have a 4 conductor cable, you don't have to do that, and it's a simple thing to switch the phase.

Also here's the waveform display. You can see that the second take is flipped outside down.

[David King]

Which position has the outside of the coil going to ground?

[David Schwab]

Which position has the outside of the coil going to ground?

Neither. Remember, there's two coils. With a standard humbucker, the finish (outside) ends of the coil are in the series link. The screw start (inside) goes to ground and the slug start goes to hot.

If you reverse wind one coil, and wire them in phase, then it's one of each.

So that's not the issue, and the outside of the coil is not separate from the inside.

The issue here is he is reversing the wires so that the coax shield, metal baseplate and the poles are now hot. That has to be the reason, as just reversing the polarity of the pickup has no effect on the tone, because it's only out-of-phase when compared to another pickup, and not on its own.

I bet if he wires the pickup to a 4 conductor cable, or even a two conductor plus shield, to remove the coils from the ground plane, he wont hear a difference.

As it is, you can't play that way, because it will be noisy, and if the string touches the metal parts on the pickup, it will short the signal out.

[JGundry]

Okay I messed with this some more until one of my alligator clips went out. and I think I got my wires crossed literally and figuratively. The mud is caused because of the ground becoming hot. I tried it again with the non reverse wound humbucker and it muds up when the ground becomes the hot. I should know better than to go with late night conclusions.

So I guess this will devolve into a Peter Green thread. So here it is, reverse winding has a little lower output middle position tone than a magnet flip and with less crunch. I swear though there is a little difference in tone to the neck pickup when reverse wound. Just a little cleaner tone on the neck reverse wound. Which one is more Peter Greenish? I don't know. Both methods have their benefits. I asked the harmonica player in my band which sounded more Greenish and he picked the reverse wound out of phase tone.

[Possum]

Here's a great downloadable video from Google, Fleetwood Mac, The Early Years:
http://video.google.com/videoplay?docid=1461283189016156759&ei=e6wLSZGfLaO2qAO8v7D5DQ&q=fleetwood+mac+the+early+years&hl=en
The download is high quality video and audio, alot of the Peter Green YouTube videos came from this video so you can really get your fill of watching live playing. How accurate the tone is though is questionable to me, the recordings of the live stuff are really lacking in treble content, the cymbals on the drums are a clue. Cool stuff though....

[David Schwab]

Okay I messed with this some more until one of my alligator clips went out. and I think I got my wires crossed literally and figuratively. The mud is caused because of the ground becoming hot. I tried it again with the non reverse wound humbucker and it muds up when the ground becomes the hot. I should know better than to go with late night conclusions.

So I guess this will devolve into a Peter Green thread. So here it is, reverse winding has a little lower output middle position tone than a magnet flip and with less crunch. I swear though there is a little difference in tone to the neck pickup when reverse wound. Just a little cleaner tone on the neck reverse wound. Which one is more Peter Greenish? I don't know. Both methods have their benefits. I asked the harmonica player in my band which sounded more Greenish and he picked the reverse wound out of phase tone.

I figured the hot ground was causing a capacitance issue. But there is also the idea that since the cores are grounded in the middle of the coil, its good to have the ground connection on the start, since having it the other way might raise the capacitance in the coil.

I've tried reverse winding one coil to try this out and didn't notice any change in tone, but that was on a bass.