slowburnaz
Commercial User
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Magnets & Copper Wire: A Pickup Building Thread
- Thread starter Freekmagnet
- Start date
Absolutely. I permanently cast my pickups in epoxy, so I always design them so that all the terminals are accessible, sticking out through the epoxy. When working with experimental pickups, you can carefully think out the wiring all day.....and then find out that it sounds much better when those two leads are reversed. Particularly when you are blending multiple coils. Sometimes the phasing doesn't make sense until you try it.
Yes, assuming you orient the coils the same way in the pickup as you wound them, that looks right. But as others pointed out, it's probably a good idea to leave options open for rewiring if you choose.
I got my hands on an 1/8" router bit that's actually 1/8" so I made some changes to my jig and got some flatwork cut last night. I screwed stops and a fence to the jig so I can just slide my plunge router back and forth instead of needing to fiddle with a collar. I like this much better.
And here's a pair of bobbins with the steel blade slugs mocked up in P formation.
And here's a pair of bobbins with the steel blade slugs mocked up in P formation.
Just waiting for the finish to dry on the covers so I can put these together and test them!
I posted that photo in a facebook group and the overwhelming reaction was that they looked like ice cream sandwiches. 
I wound the coils while I was waiting for the finish to finish curing. 6,000 turns of 43. I thought about using 42, and probably could have, but since this was a new design and I wasn't sure what would realistically fit on the bobbin, I used the 43. The blades are 1018 steel at 1/8" thick.
These bobbins are vulcanized fiber like Fender uses. I didn't have any fender style eyelets on hand, and honestly I don't like fiddling with them anyways. So for the termination of the coils, I drilled some holes in the flatwork and after winding, I pressed in some short bits of solid copper 12 gauge wire. Then I wound the coil wire around them and soldered the leads on. It worked really well, I think I will continue doing this. The wires were routed through another set of holes for strain relief. After soldering up, I put a strip of high temp tape across the "backs" of the little copper pegs so they can't short on anything.
The magnets are .2" x .5" x 2.6" C8 bars. The same bars I used as the actual blades in my last design. I bought like a dozen of these magnets so I might as well use them!
I taped up the wiring and the magnet with more high temp wire loom tape and dropped the unit into one of the wood shells.
Looks good and best yet it sounds AWESOME!
I need to make a matching bridge pickup. I'm going to leave the neck at 6,000 turns. Probably will do 6,800 or so for the bridge. I was expecting a pretty P-like tone but was surprised at where it ended up, really. These sound like they have a much flatter eq overall compared to the humbuckers I made, which - for the neck at least - is very bottom heavy. This pickup manages to be very bright without even a hint of brittleness, just lots of top end definition. And it response very politely to the preamp EQ controls. If I had to pick a commercial pickup that these sounded like, I'd probably say a split coil J more than a true P. Which I'm totally fine with, since split coil J's are about my favorite pickup (i.e. classic Barts).
Time to go make a bridge!
I wound the coils while I was waiting for the finish to finish curing. 6,000 turns of 43. I thought about using 42, and probably could have, but since this was a new design and I wasn't sure what would realistically fit on the bobbin, I used the 43. The blades are 1018 steel at 1/8" thick.
These bobbins are vulcanized fiber like Fender uses. I didn't have any fender style eyelets on hand, and honestly I don't like fiddling with them anyways. So for the termination of the coils, I drilled some holes in the flatwork and after winding, I pressed in some short bits of solid copper 12 gauge wire. Then I wound the coil wire around them and soldered the leads on. It worked really well, I think I will continue doing this. The wires were routed through another set of holes for strain relief. After soldering up, I put a strip of high temp tape across the "backs" of the little copper pegs so they can't short on anything.
The magnets are .2" x .5" x 2.6" C8 bars. The same bars I used as the actual blades in my last design. I bought like a dozen of these magnets so I might as well use them!
I taped up the wiring and the magnet with more high temp wire loom tape and dropped the unit into one of the wood shells.
Looks good and best yet it sounds AWESOME!
I need to make a matching bridge pickup. I'm going to leave the neck at 6,000 turns. Probably will do 6,800 or so for the bridge. I was expecting a pretty P-like tone but was surprised at where it ended up, really. These sound like they have a much flatter eq overall compared to the humbuckers I made, which - for the neck at least - is very bottom heavy. This pickup manages to be very bright without even a hint of brittleness, just lots of top end definition. And it response very politely to the preamp EQ controls. If I had to pick a commercial pickup that these sounded like, I'd probably say a split coil J more than a true P. Which I'm totally fine with, since split coil J's are about my favorite pickup (i.e. classic Barts).
Time to go make a bridge!
I posted that photo in a facebook group and the overwhelming reaction was that they looked like ice cream sandwiches.
So we can expect tasty tones?
So we can expect tasty tones?
I'm thinking about advertising them as having a tone like a sandwich - dark and rich on the outside and creamy in the middle!
I got a matching bridge made at 6,800 turns and the balance in output compared to the neck is good. It's nice and punchy. But still more transparent and single-coil-like than the humbuckers I made a few pages back. I hate trying to come up with words to describe pickup tones, but the bridge is once again somewhere near a traditional noiseless J, but with a wider response and a little more mid punch. Almost like a noiseless J and an underwound P had a baby. I like them enough to put a set in my main bass instead of the humbuckers I'd made. And I think I'm going to make a few more spare sets, this time with ebony tops and maple sides. Then they'll REALLY look like ice cream sandwiches! In the meantime I'm getting some more guts put together. Taking the time to think through the whole process ahead of time and planning for efficiency makes a difference. Even though these are from scratch, I can put one together in less time than it takes to put a PAF style guitar humbucker together (excluding making the wood covers at least).
I feel like between these and the humbucker design I have good contrast in terms of approach to tone. The humbuckers are much more lopsided EQ wise, but in a good way, and are splittable. Meanwhile, these are so transparent and hi-fi that I feel like you don't need the splittability - you can EQ them to get just about anything that you want. The humbuckers are sort of pre-programmed with specific EQ profiles when humbucking or tapped for single coil, and these are more of a "everything's here, take what you want and cut out the rest" profile. Two different approaches. I like it!
I know I said this before, but thank you to everyone who participates here. I feel like I'm standing on the shoulders of giants. It's very encouraging to see people sharing what they're doing. Even if I do something completely different, it's empowering to know there are other people actually doing pickups from scratch. Pickup making is very lonely once you step away from copying commercial designs.
Speaking of copying established designs, I also just finished a guitar humbucker that's a little off the rails. I present, Large Marge:
I used one of the gigantic ceramic magnets from the bass humbuckers in this, and tapped out the bobbin holes for 1/4-20 grub screws. The magnet is the same width as a PAF sized magnet but a hair longer and twice as thick, and the coils are wound to 7,500 turns, so the pickup is incredibly powerful. It would probably sound like mud with an Alnico magnet, but with this monster ceramic magnet it sounds like satan made a chainsaw out of an old harley or something.
It's like a Duncan invader but MORE!!! I don't really play much metal but some day I will build a guitar around this pickup design. Until then it's going on Reverb...
I feel like between these and the humbucker design I have good contrast in terms of approach to tone. The humbuckers are much more lopsided EQ wise, but in a good way, and are splittable. Meanwhile, these are so transparent and hi-fi that I feel like you don't need the splittability - you can EQ them to get just about anything that you want. The humbuckers are sort of pre-programmed with specific EQ profiles when humbucking or tapped for single coil, and these are more of a "everything's here, take what you want and cut out the rest" profile. Two different approaches. I like it!
I know I said this before, but thank you to everyone who participates here. I feel like I'm standing on the shoulders of giants. It's very encouraging to see people sharing what they're doing. Even if I do something completely different, it's empowering to know there are other people actually doing pickups from scratch. Pickup making is very lonely once you step away from copying commercial designs.
Speaking of copying established designs, I also just finished a guitar humbucker that's a little off the rails.
I present, Large Marge:I used one of the gigantic ceramic magnets from the bass humbuckers in this, and tapped out the bobbin holes for 1/4-20 grub screws. The magnet is the same width as a PAF sized magnet but a hair longer and twice as thick, and the coils are wound to 7,500 turns, so the pickup is incredibly powerful. It would probably sound like mud with an Alnico magnet, but with this monster ceramic magnet it sounds like satan made a chainsaw out of an old harley or something.
It's like a Duncan invader but MORE!!! I don't really play much metal but some day I will build a guitar around this pickup design. Until then it's going on Reverb...
I got a matching bridge made at 6,800 turns and the balance in output compared to the neck is good. It's nice and punchy. But still more transparent and single-coil-like than the humbuckers I made a few pages back. I hate trying to come up with words to describe pickup tones, but the bridge is once again somewhere near a traditional noiseless J, but with a wider response and a little more mid punch. Almost like a noiseless J and an underwound P had a baby. I like them enough to put a set in my main bass instead of the humbuckers I'd made. And I think I'm going to make a few more spare sets, this time with ebony tops and maple sides. Then they'll REALLY look like ice cream sandwiches! In the meantime I'm getting some more guts put together. Taking the time to think through the whole process ahead of time and planning for efficiency makes a difference. Even though these are from scratch, I can put one together in less time than it takes to put a PAF style guitar humbucker together (excluding making the wood covers at least).
View attachment 4159884
View attachment 4159880
View attachment 4159881
I feel like between these and the humbucker design I have good contrast in terms of approach to tone. The humbuckers are much more lopsided EQ wise, but in a good way, and are splittable. Meanwhile, these are so transparent and hi-fi that I feel like you don't need the splittability - you can EQ them to get just about anything that you want. The humbuckers are sort of pre-programmed with specific EQ profiles when humbucking or tapped for single coil, and these are more of a "everything's here, take what you want and cut out the rest" profile. Two different approaches. I like it!
I know I said this before, but thank you to everyone who participates here. I feel like I'm standing on the shoulders of giants. It's very encouraging to see people sharing what they're doing. Even if I do something completely different, it's empowering to know there are other people actually doing pickups from scratch. Pickup making is very lonely once you step away from copying commercial designs.
Speaking of copying established designs, I also just finished a guitar humbucker that's a little off the rails.
View attachment 4159879
I used one of the gigantic ceramic magnets from the bass humbuckers in this, and tapped out the bobbin holes for 1/4-20 grub screws. The magnet is the same width as a PAF sized magnet but a hair longer and twice as thick, and the coils are wound to 7,500 turns, so the pickup is incredibly powerful. It would probably sound like mud with an Alnico magnet, but with this monster ceramic magnet it sounds like satan made a chainsaw out of an old harley or something.
Satan's Chainsaw definitely works as a pickup name!
Yes, you've made a great example of what I call a Hi-Fi pickup. It's clean, clear, high definition, relatively flat EQ. It's designed to read the sound on the strings and accurately send it along to the amp, with minimal modification to the sound. It's the opposite end from a standard P-Bass pickup, which is specifically designed to shape the sound.
Most aftermarket pickups are made to modify the sound heard on the strings. Like what the P-Bass pickup does, but a little bit different. Taking the natural tone of a P-Bass and adjusting it into something better. Of course, better is a matter of opinion. And there's lots of debate about what is the "best sounding" P-Bass pickup.
When you put a Hi-Fi pickup in a P-Bass, you may or may not like the sound of it. The modification that the normal P-Bass pickup does will be gone. Will you like what you hear?
What made your pickup Hi-Fi is the shape of the coil and its position within the magnetic field. With the big magnet on the bottom and the narrow vertical steel blade, you've made a magnetic field that is an "I" shape. And you've wound the coil in tightly around the center. That puts all the turns into the most dense part of the field. All of the turns get the biggest voltage spike when the field lines pass through.
And, because the coil is tall and slim, the turns of wire at the outside of the coil aren't much longer than the turns in the center. The little voltage spikes in each turn are more closely aligned in timing. This is what improves clarity and definition.
In contrast, if you had made the bobbins short in height and wide, like a P-Bass bobbin, most of the turns of wire will be much further out from the dense part of the magnetic field. And the turns on the outside of the coil will be much longer in length than the turns at the center of the coil. The stackup of little voltage spikes gets spread out in timing, almost getting out of phase. That's what makes a P-Bass pickup "wooly"; thick and less clear, particularly at the low frequencies.
Almost all of my pickup development work has been with Hi-Fi style pickups. I keep pushing it farther, to see what the limits are. They work with my basses, where I'm playing with the frame structures, using the frame vibration to modify the sound on the strings.
Carry on!
@Bruce Johnson your "hi fi" designs have been a big influence on me!
In terms of getting the tall, narrow coil - that's what I was shooting for here. The steel slugs in these are 1/2" wide bar, 1/8" thick. I have some 5/8" bar which I could use to make even taller and therefore more compact coils, but that would make the pickup a little taller than a typical 3/4" tall soapbar. I'm not sure if that's really a big deal or not, though. I could work around it in my own bass designs but if I sell one of these off to someone with an unknown "standard" route for a BC pickup, I'd want to know it would fit.
I had been thinking about doing a 5/8" version and using a "standard" thickness humbucker magnet instead of these extra thick ceramic magnets, but I'm not sure how well that would work - I think these need the magnet strength from the stronger magnet. They're definitely not weak pickups, but I don't think I'd want them much weaker. I suppose I could add more turns to get some strength back but then it starts to lose the "tall and narrow" shape.
I also have some 1/16" thick steel bar. Thought about trying that as well, making the whole coil even more narrow. Less steel would mean what, though? I have a sort of vague idea but can't really explain why (except that I gleaned it from reading about other pickups and I'm not sure how much of what people described would actually transfer to my design). I wish I had a better understanding of how a magnetic material like steel influences the magnetic field. I know that in my design (or any bottom-magnet design, like a PAF or P90), the steel sort of "pipes" the magnetic field upwards towards the strings, like it's a lens that directs the field. But what difference does a wider vs more narrow piece of steel make?
I like this design as-is well enough to not have a huge motivation to immediately change anything, but I am casually curious. I am changing some of the wire routing to give a cleaner look but otherwise I think these are "done." For now...
In terms of getting the tall, narrow coil - that's what I was shooting for here. The steel slugs in these are 1/2" wide bar, 1/8" thick. I have some 5/8" bar which I could use to make even taller and therefore more compact coils, but that would make the pickup a little taller than a typical 3/4" tall soapbar. I'm not sure if that's really a big deal or not, though. I could work around it in my own bass designs but if I sell one of these off to someone with an unknown "standard" route for a BC pickup, I'd want to know it would fit.
I had been thinking about doing a 5/8" version and using a "standard" thickness humbucker magnet instead of these extra thick ceramic magnets, but I'm not sure how well that would work - I think these need the magnet strength from the stronger magnet. They're definitely not weak pickups, but I don't think I'd want them much weaker. I suppose I could add more turns to get some strength back but then it starts to lose the "tall and narrow" shape.
I also have some 1/16" thick steel bar. Thought about trying that as well, making the whole coil even more narrow. Less steel would mean what, though? I have a sort of vague idea but can't really explain why (except that I gleaned it from reading about other pickups and I'm not sure how much of what people described would actually transfer to my design). I wish I had a better understanding of how a magnetic material like steel influences the magnetic field. I know that in my design (or any bottom-magnet design, like a PAF or P90), the steel sort of "pipes" the magnetic field upwards towards the strings, like it's a lens that directs the field. But what difference does a wider vs more narrow piece of steel make?
I like this design as-is well enough to not have a huge motivation to immediately change anything, but I am casually curious. I am changing some of the wire routing to give a cleaner look but otherwise I think these are "done." For now...
When you are talking about "steel blades" are you using ordinary mild steel or low hysteresis silicon steel?
I ask because I once bought a MM clone that sounded dreadful, no matter what you did with the 3 band tone control all you got was mud.
To determine if it was the pickup or the preamp that was the culprit I cross wired the pickup to my MM SR 2 band preamp and got nothing but mud. I then cross wired the SR pickup into the clone preamp and got mud again. So it was both of them!
I built a clone SR 2 band preamp and took the ceramic bar magnets off the pickup and pushed out the steel pole pieces (mild steel I suspect) and replaced them with individual neo magnets and it sounded far better.
I'm sure randomly swapping magnet types screws up the inductance but it sounds good to me and when I played it at an open mic night got compliments about the sound of my Stingray from a fellow bassist. He didn't believe that it was a Far Eastern clone until he got close enough to read the name on the headstock.
I ask because I once bought a MM clone that sounded dreadful, no matter what you did with the 3 band tone control all you got was mud.
To determine if it was the pickup or the preamp that was the culprit I cross wired the pickup to my MM SR 2 band preamp and got nothing but mud. I then cross wired the SR pickup into the clone preamp and got mud again. So it was both of them!
I built a clone SR 2 band preamp and took the ceramic bar magnets off the pickup and pushed out the steel pole pieces (mild steel I suspect) and replaced them with individual neo magnets and it sounded far better.
I'm sure randomly swapping magnet types screws up the inductance but it sounds good to me and when I played it at an open mic night got compliments about the sound of my Stingray from a fellow bassist. He didn't believe that it was a Far Eastern clone until he got close enough to read the name on the headstock.
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All the steel I have on hand is 1018 cold rolled bar stock from mcmaster carr. So, just your average plain old low carbon mild steel. Not really sure what was going on with your pickup but it's interesting that the swap made such a difference. Neo magnets are super strong, surely that had something to do with it. I wonder what sort of turn count your pickup had.
slowburnaz
Commercial User
I think most folks use your standard "mild" steel... 1018 CRS.
I've also used some 4xx series stainless (I think it's some of the 400 series that is magnetic), but I'm not sure how common that is.
I've also used some 4xx series stainless (I think it's some of the 400 series that is magnetic), but I'm not sure how common that is.
I centred the coil on the magnets which were shorter than the steel pole pieces so the tops are about 3mm (1/8") below the pickup cover top face. The face is about 4mm from the strings so the magnets are about 7mm from the strings.
I did check for the strings choking off with the increased magnetic pull but they seem ok with the increased distance.
I've no idea how many turns there are, I should have measured the resistance, and the inductance before and after the swap but was just trying things to improve the horrible sound. When I swapped the magnets and got a dramatic improvement I tidied it up and called it done.
Here's a "stage 2" prototype of the AlNiCo 8 bass sidewinder I found in a pile of old pickups. I call it "stage 2" because it's been built, cast and cleaned up and it still works.
The cap is nickel silver and the side plates are actually the poles of the pickup. They're made of really thin 430 stainless steel. The original had .125" blades, but I replaced them with a .07" center blade and the outer ones are .02". It's crazy how much changing the thickness of the blades makes a difference. The side blades, as thin as they are, are pretty crucial to the sound; they bring a lot more low end to the sound. I've been wanting to make a pickup like this for a while.
I took some cues from @slowburnaz and used PCBs for my flatwork. Those pcbs are soldered to another PCB baseplate. I usually don't do it this way, but I had some extra room on this pickup for thicker flatwork. It actually worked out great for registering the coils and the blades before dunking the whole assembly in epoxy.
As far as tone, it sounds THICK and really bright. In addition, I've been working with Charlie Escher (aka @Passinwind) on a preamp for this pickup. He's sent me a couple of samples and so far, I'm really excited with the results. Ultimately, I'm building this as a replacement pickup for my Modelo Uno bass. The pickup and pre combo are super close to the sound I've been trying to get to for this bass since I set out to build basses and wind pickups 6-7 years ago. I like it because it sounds really aggressive. In fact, I may change the name of the bass from Modelo Uno to El Tiberón.
The cap is nickel silver and the side plates are actually the poles of the pickup. They're made of really thin 430 stainless steel. The original had .125" blades, but I replaced them with a .07" center blade and the outer ones are .02". It's crazy how much changing the thickness of the blades makes a difference. The side blades, as thin as they are, are pretty crucial to the sound; they bring a lot more low end to the sound. I've been wanting to make a pickup like this for a while.
I took some cues from @slowburnaz and used PCBs for my flatwork. Those pcbs are soldered to another PCB baseplate. I usually don't do it this way, but I had some extra room on this pickup for thicker flatwork. It actually worked out great for registering the coils and the blades before dunking the whole assembly in epoxy.
As far as tone, it sounds THICK and really bright. In addition, I've been working with Charlie Escher (aka @Passinwind) on a preamp for this pickup. He's sent me a couple of samples and so far, I'm really excited with the results. Ultimately, I'm building this as a replacement pickup for my Modelo Uno bass. The pickup and pre combo are super close to the sound I've been trying to get to for this bass since I set out to build basses and wind pickups 6-7 years ago. I like it because it sounds really aggressive. In fact, I may change the name of the bass from Modelo Uno to El Tiberón.
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slowburnaz
Commercial User
Hell yes! I like it!
So... I gotta ask. Seeing as it's a sidewinder, how did you wire it up?
Hell yes! I like it!
So... I gotta ask. Seeing as it's a sidewinder, how did you wire it up?
Haha - I think this is going to turn into a running gag on this thread!
I haven’t actually wired this particular pickup up yet. For now, I have separate terminals for the beginning and end of the coil for each coil. I’ll figure that out when I wire it into the test bass tonight.
