Adjusting pole pieces in P90s

NelsonP

Occasionally I see guitars like the below where the pole pieces have clearly been adjusted. Have a look at the bridge pickup.

Is it as simple as just turning the screw on the pole piece? And are there any do's and don'ts in terms of how you should adjust them?

OilCityPickups

Those pole pieces have been adjusted high ... probably because it's a dog ear P90 bridge, and without a shim under the pickup that's the only way to get the poles closer to the strings and get more volume. The trouble is, by raising the poles without raising the coil you will change the tone. This is because dog ears come in a one size fits all bridge pickup height ... used on solids with the strings much closer to the body ... and on semis with them relatively high.

Modulus_Amps

That guitar has the poles adjusted to follow the curve of the bridge/fret board etc. This is often suggested by guitar mags/online site. But the truth is it has no scientific justification.

A lot of people just keep them flat with minor tweaks.

The question is what are you adjusting the pole pieces to achieve?, for me it is about making the string output the same from each string, I hate going to play high up on the fretboard and the high E and B just loose volume, traditionally you would then need a boost/compressor to even things out.

So the only way to do this is to visually record the output from each string, see how out of balance they are and then adjust each pole piece. You can do this using DAW software with the guitar plugged in, record the wave forms and zoom in on them, make sure to play each string evenly. After you have done that you can throw away the compressor on your board and if needed tweak a little by ear.

This is what the output from each string looks like on most pickups if the poles are set flat IIRC

This is what the poles now look like on most of my guitars to even out the response (excuse the dust)

Funkfingers

NelsonP said:

Have a look at the bridge pickup.

IMO, once the polepiece screws protrude much beyond the filister head section, things have gone too far. 

As pointed out by TGW, raising the screws directs the magnetic field closer to the strings. The problem is that, in order to preserve the expected P90 tone, it is desirable to move the copper coil closer to the strings by the same amount. This is achieved by adding a spacer/riser between the underside of the pickup and the top of the guitar.

Dogear P90 spacers are available in a variety of materials and from a variety of sources. Forum rules prevent the naming of sources in this zone. (HINT: Take a look in the Made In The UK room.)

NelsonP said:

Are there any dos and don'ts in terms of how you should adjust them?

Essentially, the pole heights should correlate to the fingerboard radius of the host guitar. The string-to-string volume balance can then be tweaked to taste. The height "stagger" pattern will be different for strings sets with a wound G.

NelsonP

Funkfingers said:

(HINT: Take a look in the Made In The UK room.)

Nice one!

WezV

Funkfingers said:

 Forum rules prevent the naming of sources in this zone. 

First i have heard of it.

 @TheGuitarWeasel ;;; makes some laser cut ones which will be much better than the ones guitar parts supplies sell, because it will actually fit

 http://www.thefretboard.co.uk/discussion/135068/oil-city-jin-go-dog-ear-now-with-shims-included#latest

 Oooh. i feel all naughty now

OilCityPickups

Like @Funkfingers I subscribe to the 'if you can see any screw thread below the fillister head ... you've raised the pole screw too much' ... and this is worse on plastic covered P90s as the cover is fairly thick on top of the coil ... and that pole screw has come up a hell of a way to clear that! 

WezV said:

Funkfingers said:

 Forum rules prevent the naming of sources in this zone. 

First i have heard of it.

 @TheGuitarWeasel ;;; makes some laser cut ones which will be much better than the ones guitar parts supplies sell, because it will actually fit

 http://www.thefretboard.co.uk/discussion/135068/oil-city-jin-go-dog-ear-now-with-shims-included#latest

 Oooh. i feel all naughty now

Whip yourself soundly and put on some hair underpants ... works for me.

NelsonP

Through the miracles of the fretboard search engine I'd managed to track ash down - just spoke to him

Although @WezV ;I like the way this thread is going....

Modulus_Amps

@Funkfingers said:

Dogear P90 spacers are available in a variety of materials and from a variety of sources. Forum rules prevent the naming of sources in this zone. (HINT: Take a look in the Made In The UK room.)

Were does it say that? seems antiquated -  Understandable for self promotion though. I did just look at the rules too BTW

Funkfingers said:

NelsonP said:

Are there any dos and don'ts in terms of how you should adjust them?

Essentially, the pole heights should correlate to the fingerboard radius of the host guitar. .

Ditching this method saved the bridge humbucker in my LP and the bridge P90 in my SG classic, Both were going to be changed out until I adjusted them properly. still sounds like a humbucker and a P90, just better than before.

Each to there own at the end of the day if it sounds good then it is good.

peteri

In my experience how this one is set up really changes the sound of the P90 and not in a good way. 

Shim it as close as you can works for me. 

I have one guitar which came a bit like this. Shimming the P90 gave it so much more power and body 

OilCityPickups

My method ... and the one I recommend for my own dog ear P90s: Raise all pole pieces level ... not in a fingerboard curve ... and pretty much 'out' as far out as they will go without showing any gap under the pole screw head. Then shim up the pickup till the pole screws are about 2 to 2.5mm from the bottom of the strings. then adjust the pole screws in (down) to balance the strings. 

Roland

TheGuitarWeasel said:

... adjust the pole screws in (down) to balance the strings. 

How would you change the string balance on a pickup which doesn’t have pole screws, apart from raising one end of the pickup?

OilCityPickups

Roland said:

TheGuitarWeasel said:

... adjust the pole screws in (down) to balance the strings. 

How would you change the string balance on a pickup which doesn’t have pole screws, apart from raising one end of the pickup?

Well ... the original post was about P90s which have pole screws ... but for non adjustable pole pickups you really only have tilting as an option. With Strat and Tele pickups you are a little at the mercy of 'historic president' regarding pole stagger: vintage or flush ... unless you get your pickup made to your personal requirements with a stagger you know to work for your instrument/style. 

Roland

TheGuitarWeasel said:

Well ... the original post was about P90s which have pole screws ... but for non adjustable pole pickups you really only have tilting as an option. With Strat and Tele pickups you are a little at the mercy of 'historic president' regarding pole stagger: vintage or flush ... unless you get your pickup made to your personal requirements with a stagger you know to work for your instrument/style. 

Moving away from P90s and thinking about single coils with discrete magnets. Is it possible to level out the volume from each string by having different strengths or types of magnets, or does that introduce other problem? I’m thinking of dropping the low E and G, and raising D and top E in this graph:

Modulus_Amps said:

This is what the output from each string looks like on most pickups if the poles are set flat IIRC

Modulus_Amps

@Roland said:

TheGuitarWeasel said:

Well ... the original post was about P90s which have pole screws ... but for non adjustable pole pickups you really only have tilting as an option. With Strat and Tele pickups you are a little at the mercy of 'historic president' regarding pole stagger: vintage or flush ... unless you get your pickup made to your personal requirements with a stagger you know to work for your instrument/style. 

Moving away from P90s and thinking about single coils with discrete magnets. Is it possible to level out the volume from each string by having different strengths or types of magnets, or does that introduce other problem? I’m thinking of dropping the low E and G, and raising D and top E in this graph:

Modulus_Amps said:

This is what the output from each string looks like on most pickups if the poles are set flat IIRC

I have adjusted the pickups in my MIM strat, dangerous, as you can break the windings so do so at your own risk, but it worked for me and has put off changing the pickups till I can find someone who will make me a strat pickup the way I want it.

I have not adjusted my tele pickups, That guitar sound perfect as it is.

You just have to adjust the height of the magnets up and down, there are limits though depending on the length of the magnet used and if there is a back plate you can't do it.

Modulus_Amps

TheGuitarWeasel said:

Roland said:

@TheGuitarWeasel said:

... adjust the pole screws in (down) to balance the strings. 

How would you change the string balance on a pickup which doesn’t have pole screws, apart from raising one end of the pickup?

Well ... the original post was about P90s which have pole screws ... but for non adjustable pole pickups you really only have tilting as an option. With Strat and Tele pickups you are a little at the mercy of 'historic president' regarding pole stagger: vintage or flush ... unless you get your pickup made to your personal requirements with a stagger you know to work for your instrument/style. 

This is the way I have my P90 adjusted in the bridge position. Even without looking at recorded wave forms it makes sense, as the strings get thinner the pole piece needs to get closer to the string to get the same output balance.

OilCityPickups

Modulus_Amps said:

@Roland said:

TheGuitarWeasel said:

Well ... the original post was about P90s which have pole screws ... but for non adjustable pole pickups you really only have tilting as an option. With Strat and Tele pickups you are a little at the mercy of 'historic president' regarding pole stagger: vintage or flush ... unless you get your pickup made to your personal requirements with a stagger you know to work for your instrument/style. 

Moving away from P90s and thinking about single coils with discrete magnets. Is it possible to level out the volume from each string by having different strengths or types of magnets, or does that introduce other problem? I’m thinking of dropping the low E and G, and raising D and top E in this graph:

Modulus_Amps said:

This is what the output from each string looks like on most pickups if the poles are set flat IIRC

I have adjusted the pickups in my MIM strat, dangerous, as you can break the windings so do so at your own risk, but it worked for me and has put off changing the pickups till I can find someone who will make me a strat pickup the way I want it.

I have not adjusted my tele pickups, That guitar sound perfect as it is.

You just have to adjust the height of the magnets up and down, there are limits though depending on the length of the magnet used and if there is a back plate you can't do it.

I use graduated magnet strengths in several of my pickups ... for example my Wapping Wharf uses alnico 5 for the bottom three strings and alnico 2 for the top three ... 

And under no circumstances should you attempt to adjust Strat pickups by pushing up (or down) pole pieces. It may be that your MIM is one of the plastic bobbin pickups where the wire never touches the magnets ... but on all other fiber top and bottom plate designs you WILL break a winding. Certainly on an Oil City, and most of the more expensive modern Strat and Tele types. We tape the magnets for insulation before winding, and the 'grab' of the tape will not allow the poles to slide. Not only that but to protect from moisture corroding down the poles over the years, the flatwork is glued to the magnets forming a permanent seal. 

Roland

TheGuitarWeasel said:

I use graduated magnet strengths in several of my pickups ... for example my Wapping Wharf uses alnico 5 for the bottom three strings and alnico 2 for the top three ... 

So could we balance string volumes even more closely by using alnico 5 for E A and G, alnico 2 for D B and top E?

Modulus_Amps

TheGuitarWeasel said:

And under no circumstances should you attempt to adjust Strat pickups by pushing up (or down) pole pieces. It may be that your MIM is one of the plastic bobbin pickups where the wire never touches the magnets ... but on all other fiber top and bottom plate designs you WILL break a winding. Certainly on an Oil City, and most of the more expensive modern Strat and Tele types. We tape the magnets for insulation before winding, and the 'grab' of the tape will not allow the poles to slide. Not only that but to protect from moisture corroding down the poles over the years, the flatwork is glued to the magnets forming a permanent seal. 

Thats why I said do so at your own risk, i.e. it is possible to even out a strat pickup, but they are generally not designed for it. In my case if it did not work they were going in the bin anyway. Honestly I think pickup makers have missed a trick with single coils once you have even string output most pickups sound much better IME

Modulus_Amps

@Roland said:

TheGuitarWeasel said:

I use graduated magnet strengths in several of my pickups ... for example my Wapping Wharf uses alnico 5 for the bottom three strings and alnico 2 for the top three ... 

So could we balance string volumes even more closely by using alnico 5 for E A and G, alnico 2 for D B and top E?

I don't think there is a way for a pick maker to get this perfect from the get go, would depend heavily on string gauges and position of the pickup. Could probably get close but you would not know until it is fitted. @TheGuitarWeasel may disagree

Would just be easier to use the same magnet but cut them to the correct lengths to start with

OilCityPickups

Graduated magnets are used for fine tuning tone not output between the strings in general ... it's practically impossible to tell the output from a 17.5mm long alnico 5 magnet from a 17.5mm alnico 2 magnet by ear ... but the tone change between treble and bass magnets allows for rounded and creamy highs and fat, punchy bass.