3D Magnetic Field Viewer | Guitar Pickup Comparison & Mod Testing

I built a 3D Magnetic Field Viewer to do some guitar pickup comparisons + tests and get results you can see!

Fourthwall Members Links
How To Build The 3D Magnetic Field Viewer

Extra Visualiser Footage

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Waylon McPherson Guitar

My Originals Project Whiskey Soho

My Day Job "McPherson Stompboxes NZ"

[WaylonMcPhersonGuitar]

Had loads of fun making this, here's those links for my Fourthwall Members
How To Build The 3D Magnetic Field Viewer

Extra Visualiser Footage

[ngronlund]

This makes me curious about a comparison with a Lace Sensor… Thanks for doing this.

[Synthetrix]

Very cool! This is the first time I have ever see a pickups magnetic field visually represented. Well done.

[terryeaster]

I absolutely love these ideas you come up with. I would like to build the warmest thickest humbucker possible and this gives me data for that goal.
Mounting a humbucker on the back of the guitar and looking at the signal through an O'scope was brilliant. I have so many questions after that one.
Thanks again man!

[uther]

This would be really interesting to see the prs narrow field pickups

[DavidRavenMoon]

That viewer is very cool!

There’s a misconception about the way the magnet works in pickups.

The usual way it’s explained is that the string is cutting through or disturbing the lines of flux from the magnet.

But that won’t create any current. Because the magnet and coil do not move in relation to one another, no current will form. This is Faraday’s Paradox.

What’s actually happening is the magnet magnetizes the strings. The strings become moving magnets. Since the strings are moving in relative to the coil, current is produced.

The only thing different magnetic field shapes do is magnetize a different area of the strings. And of course different magnets are different strengths.

Regarding the humbucker screw mod. I’ve been doing this on pickups I make for over a decade. I find it brightens the tone up a bit. This might be due to a change in inductance. And with the field not wrapping around the back of the pickup, it’s a little stronger on the top, according to my gauss meter.

[TheJonathanNewton]

At last!! I want to see more!!!! P90s, single coils with and without the Telecaster baseplate, Jazzmasters, all kinds of pups and mods to finally lay some myths to rest or to understand better how it works!!

[Stevie_evie]

Excellent video, that was fascinating. Also really liked the music being played, I'm guessing you recorded that yourself? That was really nice & matched the video perfectly. Incredibly informative stuff, keep up the good work

[GCKelloch]

Appreciate the work. It's not really 3d because the iron filings get pulled to the bottom wall of the tank immediately. Also, the Gauss at the pole tops of the ceramic-powered pickups is probably lower than A5 poles, but the much higher permeability of the Steel poles attracts flux lines from the magnetized filings much more. Those pickups actually have less treble than an equal inductance AlNiCo pole pickup due to eddy currents caused by the highly conductive Steel poles, but the output is much higher due to how the much higher permeability pulls the flux lines from the strings more through the coil.

[onbedoeldekut]

Thank you so much for this, can you please also show us what the field looks like from the side at an angle if you can, to show more of the three dimensional array of filings where the strings would be, and how (if) the adjustable humbucker screws actually affect the field.

[Manofmystery]

It would be interesting to see Jaguar pickups with the metal casing.

[michaelhead]

Great Vid. I would love to see a classic Jaguar pickup in this test.

[MutVolran]

Humbuckers can be fitted with magnetic spacers instead of maple or plastic ones. I wonder what kind of magnetic field these will have? It was informative, thanks for your work!

[KozmykJ]

It would have been interesting to see a side view of the field lines, or did you have a problem with the filings sinking to the bottom ?
A thicker liquid might help with that ?

[robertdonosobuchner]

Great video! I have had the same idea, but I want to try to see the magnetic field in action with the strings. Your idea with this bottle is great, instead of using an acyl plate with iron powder what I was thinking about. What liquid have you used? For my experiment it has to be very "light" with no resistance to see the movements of the iron powder when a string is moving. Maybe this could be a method of comparing the resonance of materials (sustain), especially after a modification on one guitar. Maybe a bit too crazy...but I have to try this sometime.

[nucleargrizzly]

A cool comparison would be a Gibson mini humbucker and the variations of Gibson's Firebird pickups. Particularly the early "sidewinder" variant and the Bill Lawrence designed models for their '76 Bicentennial Firebird.

[ericmc]

Hi Waylon, great channel thankyou !.
I feel it would be useful to take a look at the field with strings fitted as per normal guitar usage.
Low frequency bass string visualisation might be very interesting, FFT. ☮️

[toddbrous_untwist]

Brilliant content!! THANK YOU for posting!

It would be nice to see this with more detail.
Is it a crazy idea for you to repeat this test with a more accurate alignment of the pickups to a transparent "overlay grid" so we can measure the field lines? And... MOST importantly... what are the INDUCTANCE values of each pickup? What are the total "DC Resistances" for each pickup (and individuals DCRs for each coil of the humbuckers)... only because folks look at the resistance to compare pickups instead of the inductance. Also, what are the environmental ambient temperature at the time of test... and possibly repeating the tests at varying room temps?

And if you wanna get really crazy... place your Magnetic Field Viewer on top of your guitar... pluck a string... watch the field... and look at the guitar pickup on and oscilloscope! I wonder what the multi-test average peak-to-peak voltage is?

This is academic paper type of experimentation.

Thanks again!

[ambiention]

Interesting test, but the differences “you can clearly see” weren’t obvious to me. Maybe a sheet of white paper better the pickups and the tester would’ve made it more obvious

[paulspence]

Cool vid. I reckon the next logical test would be to show the effect of different magnet types on the electrical characteristics.of.the pickups (inductance) which will also have an impact on tone.