Unusual volume pot interaction with new pickups

[big_teee]

The Peter Green Pickup had the neck pickup turned around, plus the magnet got flipped over in the rewind process.
So in the PG guitar, one pickup had one magnet north to the slug coil, the other pickup had the magnet south to the slug coil.
They work great by themselves, but are out of phase when both played together.
Flipping the magnet, or changing the pickup wiring are the things that effect phasing, turning the pickup around is cosmetic.
T

[Chuck H]

The Peter Green Pickup had the neck pickup turned around, plus the magnet got flipped over in the rewind process.
So in the PG guitar, one pickup had one magnet north to the slug coil, the other pickup had the magnet south to the slug coil.
They work great by themselves, but are out of phase when both played together.
Flipping the magnet, or changing the pickup wiring are the things that effect phasing, turning the pickup around is cosmetic.
T

So... Since the coils are still wound in the same direction when you flip the pickup, if you flip the magnet too.?. Doesn't that moot the point and render the combined pickup tone back in phase?

[big_teee]

So... Since the coils are still wound in the same direction when you flip the pickup, if you flip the magnet too.?. Doesn't that moot the point and render the combined pickup tone back in phase?

No, phase is determined by wind direction in relationship to magnet polarity.
Which way you physically turn it doesn't change that.

[Mick Bailey]

Joseph,

I would say from your description that's exactly what's happening. With the volume shift the tonality drastically changes too, all within (in this case) much less than 1/10th of a turn. I'm certain that there's nothing wrong with the wiring and there's only a problem with both pickups together. I can't rationalize why the shift is accompanied by a scratchy sound during that part of rotation, but it has to be related. Maybe the sound is the shifting frequency peaks as the notch changes.

So, as the guy from Bareknuckle said, "They are what they are and behave differently in different guitars".

[Chuck H]

No, phase is determined by wind direction in relationship to magnet polarity.
Which way you physically turn it doesn't change that.

So nothing is out of phase just turning the pickup 180 degrees?

[big_teee]

So nothing is out of phase just turning the pickup 180 degrees?

No, that won't change anything.
If you buy a new pair of Duncan humbuckers, wire both pickups in the guitar the same.
You can turn either pickup in either direction, and they will still be in phase.
When you change the wiring on one of them or change magnet polarity on one of them then they will be out of phase.
T

[Mick Bailey]

So nothing is out of phase just turning the pickup 180 degrees?

Rotating the pickup doesn't alter the direction it was wound, as it's only rotated about its own axis. In some ways no different to taking half a turn off the winding so the wire exits left instead of right. The magnet polarity is still the same in relation to the coils and it's the internal relationship that matters. Rotating a humbucker may produce a slight change in tone though, due to the pole pieces being moved either closer or further from the bridge.

I wonder if the original PG neck pickup got rotated 180 degrees in an attempt to mistakenly 'fix' the phasing caused by the rotated magnet?

[big_teee]

Rotating the pickup doesn't alter the direction it was wound, as it's only rotated about its own axis. In some ways no different to taking half a turn off the winding so the wire exits left instead of right. The magnet polarity is still the same in relation to the coils and it's the internal relationship that matters. Rotating a humbucker may produce a slight change in tone though, due to the pole pieces being moved either closer or further from the bridge.

I wonder if the original PG neck pickup got rotated 180 degrees in an attempt to mistakenly 'fix' the phasing caused by the rotated magnet?

I agree, they probably rotated it trying to correct the rewind issues.
And, I agree that turning the pickup around can alter the sound slightly, because the two bobbins have different type poles.
Another thing that could have happened on the Peter Green guitar, is if when doing the rewind the coils got wound CW, instead of CCW.
Then the bridge would be wound one way, and the rewound neck could have been wound the other way.
Combine those things with a two wire cable, You're stuck with how you built it internally.
T

[bbsailor]

Joseph,

I would say from your description that's exactly what's happening. With the volume shift the tonality drastically changes too, all within (in this case) much less than 1/10th of a turn. I'm certain that there's nothing wrong with the wiring and there's only a problem with both pickups together. I can't rationalize why the shift is accompanied by a scratchy sound during that part of rotation, but it has to be related. Maybe the sound is the shifting frequency peaks as the notch changes.

So, as the guy from Bareknuckle said, "They are what they are and behave differently in different guitars".

Mike,

The reason why they work differently in various guitars is that the height of the pickups, relative to each other, also change the notch sound just as a slight change in the volume control on one pickup. When I discovered this many years ago I thought that rather than being a defect, I could make it a feature to extend the tonal range so I began using stacked concentric volume controls and wired them to provide individual pickup control where this tone notch effect could be dialed in by a slight change in volume settings. Here is a little adjustment tip. Place the two volume controls at maximum. Adjust the volume of each pickup relative to each other by adjusting the pickup height so at the max volume there is a nice default tonal notch sound; then, a slight change in either volume control will allow tuning the notch from that default sound.

It would be good for you to put a 2-conductor shielded wire on one pickup that you can change the phase with a push-pull tone control to switch phase or use a Stew Mac 6-way selector switch.

Joseph Rogowski

[Chuck H]

No, that won't change anything.
If you buy a new pair of Duncan humbuckers, wire both pickups in the guitar the same.
You can turn either pickup in either direction, and they will still be in phase.
When you change the wiring on one of them or change magnet polarity on one of them then they will be out of phase.
T

I actually had to draw a diagram to get my head around this. Once I did all the principals made themselves clear.

That said... The PG mod is really about the magnetic phase and which coil has the stand off pole pieces I guess. Not that it matters all that much to me personally, but there's enough noise on the interwebs that I'm a little interested. Thanks for the clarification. I got it once I was able to visualize the circumstances

[big_teee]

I actually had to draw a diagram to get my head around this. Once I did all the principals made themselves clear.

That said... The PG mod is really about the magnetic phase and which coil has the stand off pole pieces I guess. Not that it matters all that much to me personally, but there's enough noise on the interwebs that I'm a little interested. Thanks for the clarification. I got it once I was able to visualize the circumstances

Here's a good diagram of one humbucker that I look at now and then.
https://www.google.com/search?q=humb...tm%3B416%3B420
The only difference in this diagram and the way most humbuckers are wired?
This diagram is Clockwise, and most vintage humbuckers are wound CCW, but the principal is the same.
T

[Chuck H]

Thanks. I DO know how humbuckers are wired. I've actually wired many. Right down to disassembly and adding four conductor leads, swapping out coils for asymmetry with factory pickups, yes, flipping magnets and a lot of stuff like that (with only a couple of casualties ) I just had trouble conceptualizing the physical vs. electrical relationships with the pickup and magnet turning around for some reason. What mattered and what didn't. I've got it now.

[MarkusBass]

In similar cases I usually disconnect the pickups from each other and record them with stereo interface. Then looking at the recorded signal allows to tell what is the problem. Out of phase problem is clearly visible in the recorded signal.

Mark

[Mick Bailey]

In this case the problem looks like an inherent feature of the pickups and the phasing is deliberate. The variables move the problem around but don't solve it. What I'll never know is if PG's guitar was in front of me, would it behave the same?

[Chuck H]

In this case the problem looks like an inherent feature of the pickups and the phasing is deliberate. The variables move the problem around but don't solve it. What I'll never know is if PG's guitar was in front of me, would it behave the same?

That's exactly the sort of thing that would bug me too. But I'm guessing YES is would. It's not a complex mod/design. PAF type pickups are indeed mostly a little different, but they're probably not "all over the map". So that part should have some consistency. Then... Turn pickup, flip magnet, use vintage type, two pickup wiring. It doesn't seem like a complex enough set of variables to expect widely variable results. But I'm far from an expert on PAF's and don't have personal experience with this mod. Just trying to put your mind at ease.