Pickup Testing: Complete Beginner's Guide

[kingvox]

Made this guide a while back, and updated and re-published it recently here:



This is for anyone curious. All credit to Antigua Tele and Ken Willmott for walking me through the process step by step. Also shout out to Rob DiStefano as I never would have even started winding pickups without his massive and generous amount of help over the years.

Just trying to pay it forward by sharing this information in an easy-to-understand way that I wish was available when I started out doing this.

Equipment and testing methods are all covered in detail: WT10A Gauss Meter, DE-5000 LCR Meter, and Velleman USB Oscilloscope paired with a Ken Willmott Integrator. This covers all the basics you need, with a stripped down bare-minimum format that even a simpleton like me could follow. That's part of why I made it in the first place -- so I won't forget.

 

[Humbuckers]

Appreciate the video. Some day I really ought to shell out to get the equipment needed to do this.

Can you share any testing data you’ve gathered? I’ve found Antigua’s database tremendously informative as far as understanding and selecting pickups.

 

[uriah1]

whoa.

 

[kingvox]

Appreciate the video. Some day I really ought to shell out to get the equipment needed to do this.

Can you share any testing data you’ve gathered? I’ve found Antigua’s database tremendously informative as far as understanding and selecting pickups.

I'm slowly working on a comparison video, or series of videos. I wind pickups, so my basis for evaluation is all based on the components I select and how I put them together.

As an example, here are two of my "Super Heavyweight" Strat pickups, made identically except one with A5 and one with A8 mags. It's worth noting that the A8 only come in .195" diameter, and the A5 I use are .187" diameter. So it's even more notable that the A8 has lower inductance, as the wider footprint of the coil *should* mean that the inductance would be higher compared to .187" mags, similar to how turn-for-turn a Telecaster pickup will have more inductance than a Strat pickup, since the wire is traveling a greater distance per turn.

I also have a gram scale and have gone back and forth about using the actual weight of the wire as another variable, which I've never seen anyone do. That may be a decent approximation of the actual difference in length of wire, though you'd have to test before wax potting I suppose to eliminate that as a potential variable for weight.

There's so much that goes into all of this. And this is the stuff I have to sort out in my head before making a video. So as you can see, I have my work cut out for me. I recently made a P90 and did a couple comparison tests with Strat pickups as well. I have dozens of bode plots but the problem is gonna be organizing it into something cohesive and relevant. Comparisons might be the best way, and instead of just doing independent bode plots of all the random pickups I wind, I intend to make more comparisons controlling for one variable at a time.






So, that's what I'm planning. More comparisons and more controlled variables, e.g. same exact coil but swap the magnets out (A2, A3, A5, A8, etc.), measure inductance and resonant peak. Same bobbin dimensions but wind with 42 vs 43, 44, 45 etc. Comparing them with the same and different turn counts.

The advantage of making your own pickups is you can control all these variables. The only thing missing is another form of measurement, perhaps impulse response measurements for pickups that could identify things like attack and decay. After making so many pickups myself and testing them out, I'm convinced there are metrics that are very important that aren't covered by LCR meter and oscilloscope readings.

That doesn't even include running pickups together, which is a huge deal. For example, I really am loving my super overwound bridge pickup and 'underwound' neck pickup on my Strat. I run them independently, but also in series and parallel, both in phase and out of phase. The huge discrepancy between the output and resonant frequency of the two pickups makes for some really interesting tones when you run them together, much more interesting to my ear than two pickups of similar output and resonant frequency. But I currently have no way of showing what that looks like, data wise.

Lots of ideas bouncing around in my ADD brain. In short, I'd love to share what I've learned, but it's gonna take a lot of processing and thinking. For now I mostly just have random bode plots of pickup 'recipes' I've made, but without direct comparisons to a standard make and model the numbers don't mean much.

 

[old wrench]

Lots of good info on testing

Thanks for putting it all together in one place!

.

 

[Humbuckers]

Really looking forward to seeing what you’ve learned. I’m sure this is something you’ve already thought of, but I’d also like to see how all this data translates to real-life in-the-guitar, through-the-amp application.

For instance, from data like yours and Antigua’s tests, you’d think that telecaster bridge pickups come in a much larger range of power than actually pans out in reality.

There’s something about the pickup’s position or limited amount of string movement in that position that means that the actual difference in apparent volume between a vintage output pickup Tele pickup and something like a Quarter Pound isn’t that great. There’s much more of an effect on fullness/treble response than actual perceived loudness.

Antigua actually discusses the bridge output ceiling in this post:

https://guitarnuts2.proboards.com/thread/7882/output-amplitudes-various-pickups

Also, in my experience it seems that there isn’t a straight more-winds = darker tone that I would have believed from just looking at stats, even controlling for other pickup construction variables. I’ve noticed there’s a sort of wave-like progression where lower winds can sound warmer, higher winds than that sound brighter, higher winds than that sound warmer again, then higher winds than that sound brighter again, and so on.

 

[kingvox]

Really looking forward to seeing what you’ve learned. I’m sure this is something you’ve already thought of, but I’d also like to see how all this data translates to real-life in-the-guitar, through-the-amp application.

For instance, from data like yours and Antigua’s tests, you’d think that telecaster bridge pickups come in a much larger range of power than actually pans out in reality.

There’s something about the pickup’s position or limited amount of string movement in that position that means that the actual difference in apparent volume between a vintage output pickup Tele pickup and something like a Quarter Pound isn’t that great. There’s much more of an effect on fullness/treble response than actual perceived loudness.

Antigua actually discusses the bridge output ceiling in this post:

https://guitarnuts2.proboards.com/thread/7882/output-amplitudes-various-pickups

Also, in my experience it seems that there isn’t a straight more-winds = darker tone that I would have believed from just looking at stats, even controlling for other pickup construction variables. I’ve noticed there’s a sort of wave-like progression where lower winds can sound warmer, higher winds than that sound brighter, higher winds than that sound warmer again, then higher winds than that sound brighter again, and so on.

That's one reason I'm working on averaging frequency responses from pickups I make. However, I do think that more winds = darker tone is generally accurate, everything else being equal -- that is to say, if you had a pickup with 8,000 turns of wire, and spliced on an additional 1,000 turns, the resonant frequency would come down slightly, and same if you add another 1,000 turns, etc.

That will also be in line with the inductance coming up.

How this presents audibly is another matter, however, and resonant frequency/inductance might not be telling the whole story. That's one reason I feel like it would be ideal to have additional testing.

At the same time, just listening by ear may be the ultimate arbiter of what an *individual* prefers, but hard numbers are always required for stating what is reality and what is not. I'd be curious what Antigua or Ken would think about what additional tests could possibly be done, perhaps something with Impulse Responses, to show more about how the magnetic field/Gauss strength influences the attack/decay/tone in general -- in hard, real numbers. Observable data that we can test for and share like we can with bode plots.

I will say I've made a couple real oddball pickups with quite high inductance for a Strat pickup, say 4.5 Henries, with a very high resonant frequency. On one of those I used steel poles and a neodymium bar magnet. In that case, higher inductance did not translate to resonant frequency at all, and the pickup was very painfully bright sounding. I was pretty surprised by that, and that was with 9,000 or 10,000 turns of wire, quite a bit more than your standard 8,000 turns.

My current bridge pickup on my Strat is 18,000 turns of 46AWG wire on a coil that's .500" tall, with A5 rod magnets. You can see a demo I did with it here:



That's comparing the two pickups, and even though they're in different positions, the drastic difference in turn count can be readily heard. 7,600 turns of wire on the neck pickup, 18,000 on the bridge.

I recently made an A8 rod magnet pickup that sounded great, with the same number of turns, but on a taller bobbin. The taller bobbins get less inductance compared to shorter bobbins for the same turn count, and A8 has a lower inductance than A5. The interesting thing is the A8 is not that much stronger by my measurement (about 200-300 Gauss stronger than A5), but it did have a clarity to it that I can't quite explain.

Now, an A5 pickup wound to the same specs -- inductance and resonant frequency -- I'm not sure I could tell the difference between that and A8 in a blind test.

I've also made a humbucker using only fiberboard and alnico mags -- no metal baseplate, no steel slugs or screws. So the ground wire is not connected to anything. And it sounds great. I wound the heck out of it and it ended up with an inductance around 8 Henries, is insanely loud but also has super clear high end, almost piercing if you're not careful, with a monstrous low end that hits the amp really hard and breaks it up like crazy. I love it for open G and drop D. However they're a pain to make so I almost never do them anymore. But that was another interesting one.

The super overwound Strat pickups I make -- I'm curious what the Bare Knuckle Sinners measure out at. Mine is over 11 Henries, which you can hear in that demo, which is stupidly thick for a Strat single coil, but I personally love it. Definitely not for everyone, but for me, the clean/sparkly/Stratty tones only come from the neck pickup. That's all I personally care about. Now if someone was gonna play surf guitar, you need a low wind Strat bridge pickup or it's just not going to work.

I talked to Antigua a bit and I would like to try making a tapped coil that actually worked as it should. He told me in the past how maybe one reason they're not popular is the capacitance on the tap is driven up so much that it's basically identical to the full coil if you turn your volume knob down to 8 or so. So it's pointless.

And I can confirm that. The tapped coil capacitance is stupidly high as it's affected by all the winds that come after it. I'm going to try experimenting to see if insulating the coil and *then* winding over the insulation (Kapton tape) is enough to break up that capacitance.

Anyway. Even now I can't decide what I like best for my own Strat, except for the neck pickup. I have been making Strat neck pickups with 7,600 turns of wire on a .500" tall coil (about .070" taller than traditional vintage Strat pickups, which are around .430" tall between the flatwork) for over 5 years and to me, that is just perfect.

I also just realized a funny coincidence: I make 'classic' Strat pickups with .430" coil heights, 'modern' with .500" coil heights, and then the tall ones with .570" coil height. The increments of .070" are just a funny coincidence. But as I mentioned earlier, taller coils = less inductance per turn compared to shorter, as the wire is traveling a shorter distance on taller coils.

Another good question is whether it's turn count that matters or the total length of wire used from end to end. Insulation thickness and wire gauge will affect the distance each turn of wire travels. Same goes for what you wrap the mags with prior to winding. Thick cloth tape around the mags will make for a thicker coil for the same turn count compared to thin tape.

Everything makes a difference. For human hearing, I think the practical difference probably requires less nuanced changes than people would like to think. That's one reason I like making stupidly overwound pickups, or pickups that are wound less than you'd typically find. I like the idea of making stuff that you can't readily find elsewhere, and that have very obvious differences.

I will say I'm not decided on a Strat bridge pickup yet. I've made hundreds and I still can't tell what I prefer. If I can figure out a way to make a tapped coil actually worthwhile, that might be a possible solution. For now, I'm on the fence about whether the 32k bridge is too thick and dark for me or not.

Another factor to consider is how it plays with the other pickups when wired in series/parallel and in phase/out of phase. I almost liked the sharper, clearer sounding A8 pickup better, but it wasn't as interesting when combined with the neck pickup. Also, the super high inductance and darker tone of the pickup in that video I linked to is also great for metal and super high gain in general.

Fuzz and high gain can all nullify much of what a pickup sounds like, but extreme differences are obvious. "Underwound" pickups can sound 'sharp' and 'fizzy,' while "overwound" pickups can have a nice 'creamy' and 'thick' sound. I hate using words like that. But it's true. I would describe that super 'hot' Strat bridge pickup I started making recently as very warm and very subdued; it'll hit an amp hard but at that kind of resonant frequency, any classic Strat sparkle you'd expect to hear is pretty much completely gone. For some people that might be a good thing.

However, oddly, it still does sound like a Strat pickup in its own way. I believe the main part of a pickup's tone is the bobbin design itself. The dimensions are very important. Any time I've done vintage reproductions for anyone I've always used .430" tall coils, not only to get them to look right, but to sound right. And it's important to note the bobbin dimensions when noting what turn count manufacturers used to use back in the day -- and how they prepped or wrapped the magnets *before* winding.

 

[kingvox]

Lots of good info on testing

Thanks for putting it all together in one place!

.

Absolutely!

 

[Humbuckers]

Regarding taller bobbins having less inductance, do you have any idea how a taller pickup with X inductance would sound compares to a standard size pickup wound to the same inductance? Would they sound the same or would factors other than the inductance cause them to sound different?

It’s like the taller Twisted Tele style neck pickups: is it the tallness of the bobbin, the increased gauss of tall magnets, or the 42 awg wire that makes them sound the way they do?

Also, if one increases the bobbin height to increase the resonant peak for a given number of turns of wire, I would imagine you’re also lowering the output a bit by making the lowest part of the coil farther from the strings, which sort of works against the whole reason to make a taller coil rather than put on less turns of wire.

Just speculating here, and would love your thoughts and insights.

That's one reason I'm working on averaging frequency responses from pickups I make. However, I do think that more winds = darker tone is generally accurate, everything else being equal -- that is to say, if you had a pickup with 8,000 turns of wire, and spliced on an additional 1,000 turns, the resonant frequency would come down slightly, and same if you add another 1,000 turns, etc.

That will also be in line with the inductance coming up.

How this presents audibly is another matter, however, and resonant frequency/inductance might not be telling the whole story. That's one reason I feel like it would be ideal to have additional testing.

At the same time, just listening by ear may be the ultimate arbiter of what an *individual* prefers, but hard numbers are always required for stating what is reality and what is not. I'd be curious what Antigua or Ken would think about what additional tests could possibly be done, perhaps something with Impulse Responses, to show more about how the magnetic field/Gauss strength influences the attack/decay/tone in general -- in hard, real numbers. Observable data that we can test for and share like we can with bode plots.

I will say I've made a couple real oddball pickups with quite high inductance for a Strat pickup, say 4.5 Henries, with a very high resonant frequency. On one of those I used steel poles and a neodymium bar magnet. In that case, higher inductance did not translate to resonant frequency at all, and the pickup was very painfully bright sounding. I was pretty surprised by that, and that was with 9,000 or 10,000 turns of wire, quite a bit more than your standard 8,000 turns.

My current bridge pickup on my Strat is 18,000 turns of 46AWG wire on a coil that's .500" tall, with A5 rod magnets. You can see a demo I did with it here:



That's comparing the two pickups, and even though they're in different positions, the drastic difference in turn count can be readily heard. 7,600 turns of wire on the neck pickup, 18,000 on the bridge.

I recently made an A8 rod magnet pickup that sounded great, with the same number of turns, but on a taller bobbin. The taller bobbins get less inductance compared to shorter bobbins for the same turn count, and A8 has a lower inductance than A5. The interesting thing is the A8 is not that much stronger by my measurement (about 200-300 Gauss stronger than A5), but it did have a clarity to it that I can't quite explain.

Now, an A5 pickup wound to the same specs -- inductance and resonant frequency -- I'm not sure I could tell the difference between that and A8 in a blind test.

I've also made a humbucker using only fiberboard and alnico mags -- no metal baseplate, no steel slugs or screws. So the ground wire is not connected to anything. And it sounds great. I wound the heck out of it and it ended up with an inductance around 8 Henries, is insanely loud but also has super clear high end, almost piercing if you're not careful, with a monstrous low end that hits the amp really hard and breaks it up like crazy. I love it for open G and drop D. However they're a pain to make so I almost never do them anymore. But that was another interesting one.

The super overwound Strat pickups I make -- I'm curious what the Bare Knuckle Sinners measure out at. Mine is over 11 Henries, which you can hear in that demo, which is stupidly thick for a Strat single coil, but I personally love it. Definitely not for everyone, but for me, the clean/sparkly/Stratty tones only come from the neck pickup. That's all I personally care about. Now if someone was gonna play surf guitar, you need a low wind Strat bridge pickup or it's just not going to work.

I talked to Antigua a bit and I would like to try making a tapped coil that actually worked as it should. He told me in the past how maybe one reason they're not popular is the capacitance on the tap is driven up so much that it's basically identical to the full coil if you turn your volume knob down to 8 or so. So it's pointless.

And I can confirm that. The tapped coil capacitance is stupidly high as it's affected by all the winds that come after it. I'm going to try experimenting to see if insulating the coil and *then* winding over the insulation (Kapton tape) is enough to break up that capacitance.

Anyway. Even now I can't decide what I like best for my own Strat, except for the neck pickup. I have been making Strat neck pickups with 7,600 turns of wire on a .500" tall coil (about .070" taller than traditional vintage Strat pickups, which are around .430" tall between the flatwork) for over 5 years and to me, that is just perfect.

I also just realized a funny coincidence: I make 'classic' Strat pickups with .430" coil heights, 'modern' with .500" coil heights, and then the tall ones with .570" coil height. The increments of .070" are just a funny coincidence. But as I mentioned earlier, taller coils = less inductance per turn compared to shorter, as the wire is traveling a shorter distance on taller coils.

Another good question is whether it's turn count that matters or the total length of wire used from end to end. Insulation thickness and wire gauge will affect the distance each turn of wire travels. Same goes for what you wrap the mags with prior to winding. Thick cloth tape around the mags will make for a thicker coil for the same turn count compared to thin tape.

Everything makes a difference. For human hearing, I think the practical difference probably requires less nuanced changes than people would like to think. That's one reason I like making stupidly overwound pickups, or pickups that are wound less than you'd typically find. I like the idea of making stuff that you can't readily find elsewhere, and that have very obvious differences.

I will say I'm not decided on a Strat bridge pickup yet. I've made hundreds and I still can't tell what I prefer. If I can figure out a way to make a tapped coil actually worthwhile, that might be a possible solution. For now, I'm on the fence about whether the 32k bridge is too thick and dark for me or not.

Another factor to consider is how it plays with the other pickups when wired in series/parallel and in phase/out of phase. I almost liked the sharper, clearer sounding A8 pickup better, but it wasn't as interesting when combined with the neck pickup. Also, the super high inductance and darker tone of the pickup in that video I linked to is also great for metal and super high gain in general.

Fuzz and high gain can all nullify much of what a pickup sounds like, but extreme differences are obvious. "Underwound" pickups can sound 'sharp' and 'fizzy,' while "overwound" pickups can have a nice 'creamy' and 'thick' sound. I hate using words like that. But it's true. I would describe that super 'hot' Strat bridge pickup I started making recently as very warm and very subdued; it'll hit an amp hard but at that kind of resonant frequency, any classic Strat sparkle you'd expect to hear is pretty much completely gone. For some people that might be a good thing.

However, oddly, it still does sound like a Strat pickup in its own way. I believe the main part of a pickup's tone is the bobbin design itself. The dimensions are very important. Any time I've done vintage reproductions for anyone I've always used .430" tall coils, not only to get them to look right, but to sound right. And it's important to note the bobbin dimensions when noting what turn count manufacturers used to use back in the day -- and how they prepped or wrapped the magnets *before* winding.

 

[kingvox]

Regarding taller bobbins having less inductance, do you have any idea how a taller pickup with X inductance would sound compares to a standard size pickup wound to the same inductance? Would they sound the same or would factors other than the inductance cause them to sound different?

It’s like the taller Twisted Tele style neck pickups: is it the tallness of the bobbin, the increased gauss of tall magnets, or the 42 awg wire that makes them sound the way they do?

Also, if one increases the bobbin height to increase the resonant peak for a given number of turns of wire, I would imagine you’re also lowering the output a bit by making the lowest part of the coil farther from the strings, which sort of works against the whole reason to make a taller coil rather than put on less turns of wire.

Just speculating here, and would love your thoughts and insights.

This is one reason I do YouTube videos, and at some point I may do one addressing these points. The only real way to know is to test it, and the means I have to test are still limited to my LCR meter and Oscilloscope, which again may not show the whole picture.

Another program would also be nice, as lining up the grid markers on the bode plot is cumbersome, and not as accurate as a button would be. If I could just click a button to find the resonant peak, which I'm surprised the Velleman software can't do, that would be a lot more accurate.

Long story short, I'm not sure. These are similar questions I have.

A .471" A5 rod magnet will measure around 750 Gauss or so, while a .719" A5 magnet will measure around 950-1,000 Gauss. .781" tall A5 mags will measure around 1,100-1,200 Gauss. It depends on the manufacturer as well, I'm sure. These are just approximations of pickups I've tested that I've made myself.

Taller magnets will tend to resist self de-magnetizing more, which is a non-issue to begin with so it's not something I consider when making pickups.

The taller bobbins are exclusively to get more turns of wire on. I was doing that before I discovered 46 AWG, which kind of turned everything on its head. On a .500" bobbin you can fit more turns of 46AWG than you would ever need. I could probably easily get over 20,000 turns of wire on a .500" Strat bobbin with 46AWG, which would just make the pickup sound like mud. Even the one I'm currently using, at 11 Henries and a resonant peak of around 1.6kHz or so, is already very dark. I happen to like that but it certainly isn't for everyone.

You also have to consider that, in theory, using thinner wire on the same coil height is the same thing as using the same gauge wire and making the coil height taller.

In general what we expect to see is less output, less inductance, and a higher resonant frequency. Though the difference may be quite small.

You also can consider what you wrap the magnets with prior to winding. A thinner wrap vs. a thicker wrap will start the winding process off in a different place. It effectively makes the bobbin footprint wider, albeit a small amount. Now an interesting experiment would be double wrapping the magnets to make the coil wider -- I'm curious how that would impact the sound as well. How important is the proximity of the coil to the magnets? If you had, say, .020" between the magnets and the coil, which is a ridiculously thick amount, what would happen then?

I might have to experiment just to see. With very thin wire you could get away with something like that and still have an overwound pickup.

There are lots of possibilities. Until recently, tall bobbins were a "form follows function" thing for me. 46AWG is very expensive (80 dollars a pound, currently) unless you order it directly from China. I'm actually thinking of ordering one of their giant 4kg rolls even though I don't make enough money selling pickups to justify it Just in case I can't get it anymore. Not including shipping and tax, from Magnet Wire Supply as of a month ago, it's 80 dollars a pound....ouch.

Anyway, it becomes a game of whack-a-mole to manipulate things like bobbin height. I'll probably have to conduct some actual tests, making some pickups to very controlled specifications, to see if there's any real merit to making a bobbin taller for the sake of making it taller.

I also admit I haven't paid enough attention to the resonant peak. I focus so much on the actual frequency that I forget the dB spike AT that frequency is also important. That will dictate how dramatic the 'EQ' is, with a larger resonant peak at a particular frequency meaning it will be more prominent. There is a curve too on the bode plot that I also don't look at carefully enough. I tend to focus only on the peak and neglect the rest of the plot, which may be a mistake, though to be fair I'm not aware of any system to meaningfully analyze the data of the entire plot -- just the peak.

 

[kingvox]

I'll add that this has been a conflict for me in terms of designing my own pickups. What's the point of using taller bobbins and thicker wire, vs. shorter bobbins and thinner wire? Is there any real difference? Maybe, maybe not. And maybe if there is, we simply don't have the tools to collect the data to show why.

The taller bobbin putting more turns of wire farther away from the strings is a moot point in my experience. The only reason to use a super tall coil is to add more turns of wire, and I remember on one set I did for someone with 15,000 turns of wire on a .781" mag bobbin, it was more than twice as loud as the 8,000 turn neck pickup I did for them. The neck pickup was around 2 Henries and the bridge pickup around 7.7 Henries.

I've made Strat style pickups using PAF bobbins, which are about .250" thick, which is half the height of the typical Strat pickups I use. I'd have to test them to know for sure, because at baseline I couldn't hear any real difference, except I remember the PAF style pickup sounding thinner given the same number of turns. Now that I'd have to compare, as in theory it should be thicker sounding -- but maybe the shorter mags play into that. Again, can't say without tests. I'm extremely disorganized so it really does take a lot for me to run tests and keep things in legible formats and files.

But I'm gonna make a note of this. It would be a good video. To compare the same turn count in various bobbin heights. One variable at a time. I'd say comparing the weight of copper using a gram scale, and getting the same weight of copper on two different height pickups, as well as comparing the same turn count, might give a more complete picture.

 

[kingvox]

Updated (again). New version of the video is here:



From 5:54 forward, I've revised everything. Using the spreadsheets makes an absolutely huge difference, and saving the data files as .txt files allows you to do whatever you want with the data at any point in the future. Invaluable for data hoarders like myself.