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Post by antigua on Apr 22, 2023 14:16:37 GMT -5
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Post by ms on Apr 22, 2023 14:42:31 GMT -5
If you want, or at least are willing, to use a pickup with a low resonant f, you would expect it to be hum bucking, because it is possible and desirable. So what are these pickups for? Surely they are not making the claim that the electrical shielding can reduce magnetic hum any where near as much as the cancellation obtained with a humbucker.
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Post by antigua on Apr 22, 2023 16:17:07 GMT -5
If you want, or at least are willing, to use a pickup with a low resonant f, you would expect it to be hum bucking, because it is possible and desirable. So what are these pickups for? Surely they are not making the claim that the electrical shielding can reduce magnetic hum any where near as much as the cancellation obtained with a humbucker. I bought them for the looks and the novelty mostly, I don't really expect that they will surprise me sonically, and I think that anyone at Fender really thought they would sound different, they wouldn't have waited this long to make use of it in more of their pickups. In some of the marketing videos, Tim Shaw says Seth Lover used CuNiFe in order to get around the Gibson PAF patent, and I think in truth that's the extent of it's utility. Shielding is an issue I don't understand 100%, but what I gather is that full shielding is ideal, although partial shielding is still beneficial. Interestingly the base plates are steel, so they're not just shielding but also factor into the magnetic circuit. Some people believe the steel shield on the bottom lowers the reluctance to a meaningful degree. I don't think it does, but a lot of people seem to believe it does, maybe Tim Shaw does. |
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Post by antigua on Apr 22, 2023 17:08:00 GMT -5
Here's a video by Andertson Music in the the UK, interviewing Tim Shaw
This is the first time I've ever seen an interview with Tim Shaw. All I knew about him is that he was associated with a lot of claims about guitar pickups, by way of Fender marketing materials, which seemed dubious based on all that I've come to learn about how pickups work. This video is no exception, he makes a handful of claims that seem at odds with the facts as I understand them.
It starts out with a story of how he learned to make pickups with the help of Bill Lawrence at Gibson in the 70's. He notes that the top is open, so the damping is not as substantial as a closed top, that much seems to be a true statement based on experiments presented in this forum.
He says in video that the open top Tele neck style cover was chosen to make room for all the parts in the pickup, he says there are lots of parts involved here. Maybe this was true in an early version of the design, but as the picture above shows, there's quite a lot of space remaining between the coil and the edge of the cover. Certainly they could have fit a plastic cover over the final version of the coil. Maybe they weren't originally planning to use 44 AWG wire, which would have resulted in a fatter coil for sure.
He says at 13 minutes "because the pickups doesn't have a whole lot of iron in it, it's a pretty quiet pickup in terms of sixty cycle hum", but I can't think of any physical reason for how that could be a true statement, and if it were true, pickup makers would have exploited that fact a lot sooner, like maybe seventy years ago.
Several times he talks about the CuNiFe or or the FeCrCo imparting a different tone, he says at 20 minutes that in the context of a Tele that the CuNiFe was too polite, and he even makes a funny voice, mocking a polite guitar pickup that is able to speak and describe its own politeness. The guys at Gitek did a pretty deep analysis of the Wide Range Humbucker and CuNiFe screws, and did show that it had a lower permeability and a higher resonant peak, and tweaked the sound for that reason. He notes that Seth Lover made the WRHB coils larger to compensate for the lower inductance of the CuNiFe, that seems like a reasonable explanation, and maybe it relates to why they gave these single coils such a high inductance through the coil design.
The idea that the lower permeability can change the sound is probably more limited than how he describes, because all that's really happening is that the reluctance between the coil and string is increasing or decreasing. But... he says in the video at about 19 mins 30 seconds that CuNiFe and AlNiCo have different transient profiles, he uses the words "onset transient, rise time", saying the CuNiFe has a slower attack. As far as I know, guitar pickups do not have unique transient properties, which is to say, they don't do something in the beginning of their operation that is different during the duration of their operation. There are issues of hysteresis in the metal, possibly causing distortions in the output signal, but that is not specific to the transient, because the effects of hysteresis are always in play, not just at the first string pluck. What I've found is that what makes an electric guitar transient unique is the spike in high frequency content that you get when you pluck a stiff steel string with a stick, pointy plectrum, and that the frequency response of the pickup can make the transient of the string pluck see very different through the fact that it's filtering out the burst of high frequency content, but the pickup itself doesn't have something like a "slew rate". I suspect that confusing tube amplifier slew rates, and the filtering action of transient harmonics is what leads to a mistaken idea of pickups having a unique attack characteristic.
I think a lot of Tim Shaw's commentary about these pickups lacks technical merit, but I'm glad Fender made these pickup because they look cool, they're conversation pieces, and they might end up sounding unique or pleasantly surprising once I can make the time to install them.
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Post by gckelloch on Apr 22, 2023 18:29:09 GMT -5
...and I don't think Bill would have approved of the presentation. These pickups are almost on the level of the original Micro-Coils, but with higher inductance, lower efficiency, and the benefit of a much higher price tag  . The advantage of the screws is for string output balance and lower to upper harmonic balance without the high freq loss from Steel screws. It makes more difference with thinner wire coils, but it even matters with my GFS P90. Lowering the coil and raising the pole screws sounds brighter. Not sure I understand the effect of reluctance, but given the large output difference of the Tele neck and bridge pickups (which seems much more than the inductance difference would cause), couldn't it just be that the wider Steel plate draws more of the string flux lines through the coil? Is the Steel plate also thicker? I just mod'd a pair of Filtertron Blacktops for my new build. When I first tried attaching the A4 magnet between and touching the pole screws on the bottom, it affected the field at the top of the screws so there was a null at the center of the screw heads. A screwdriver would pull to the outer edges of the head. I then tried attaching and touching one side of the Steel bars I got (which are thinner than the A4 magnet) to the pole screws in one of the coils. The null on the head also happened in that set of screws. That must have some effect. Maybe it widens the aperture window, if not also weakens the field at the top, which it feels like it does. Moving the bar off the screws decreases the effect. He may just be using the trendy terminology "slow attack" to describe how the weaker magnet affects the transient character. He may not understand what's actually happening, but it has become a common way to describe pickup sound, like the incorrect use of "compression". |
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Post by antigua on Apr 23, 2023 0:52:55 GMT -5
...and I don't think Bill would have approved of the presentation. These pickups are almost on the level of the original Micro-Coils, but with higher inductance, lower efficiency, and the benefit of a much higher price tag . The advantage of the screws is for string output balance and lower to upper harmonic balance without the high freq loss from Steel screws. It makes more difference with thinner wire coils, but it even matters with my GFS P90. Lowering the coil and raising the pole screws sounds brighter. Not sure I understand the effect of reluctance, but given the large output difference of the Tele neck and bridge pickups (which seems much more than the inductance difference would cause), couldn't it just be that the wider Steel plate draws more of the string flux lines through the coil? Is the Steel plate also thicker? I just mod'd a pair of Filtertron Blacktops for my new build. When I first tried attaching the A4 magnet between and touching the pole screws on the bottom, it affected the field at the top of the screws so there was a null at the center of the screw heads. A screwdriver would pull to the outer edges of the head. I then tried attaching and touching one side of the Steel bars I got (which are thinner than the A4 magnet) to the pole screws in one of the coils. The null on the head also happened in that set of screws. That must have some effect. Maybe it widens the aperture window, if not also weakens the field at the top, which it feels like it does. Moving the bar off the screws decreases the effect. He may just be using the trendy terminology "slow attack" to describe how the weaker magnet affects the transient character. He may not understand what's actually happening, but it has become a common way to describe pickup sound, like the incorrect use of "compression". Bill Lawrence seemed to favor the use of steel poles or blades with a magnet on the bottom, his designs mostly avoided having magnetized pole pieces. I agree that he'd probably not love the design, but he seemed to appreciate diversity, he wasn't devoted to one particular design concept, as a lot of other pickup makers seem to be. You make a good point that these are essentially like AlNiCo poled single coils with adjustable pole pieces, which is a first for the pickup market AFAIK. I tend to prefer flat profile pole pieces to such an extent that I overlooked that benefit. The big difference in output between between the Tele neck and bridge is that one is about 3 henries inductance, and the other is 6 henries. Doubling the inductance from neck to bridge is a huge leap. Similar to a JB Jazz combo, 4 henries with the Jazz, close to 8 henries with the JB. Just as a reminder, the inductance is not the cause of the output, it's just a corollary, as is DC resistance, but it correlates much more closely than resistance, because the cause of high output and the cause of high inductance are closely related, where as the cause of high DC resistance is not closely related. The main reason the base plates don't assist the reluctance path very much, no matter the size, is because the magnetic gap is mostly air. Even with a Jaguar pickup, which has a "claw" shaped steel base plate, it replaces a lot more air than do these base plates, but still, it does not displace enough air gap to have a substantial effect on the reluctance. The best you can do is replace air in the core of the coils, which is what the slugs or screws do, or replace the air between the guitar strings and the coil, and the way to do that is to just have the pickup set very close to the guitar strings. This subject matter relates to inductor design, so if you read about the significance of air gaps in inductor enclosures, it's informative. I understand that he might use incorrect terminology to be relatable, but he's been called a "pickup guru", I think it's fair to set a higher standard here. |
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Post by ms on Apr 23, 2023 10:53:16 GMT -5
CuNiFe is low permeability and conductivity. In order to assess how useful it is, consider two ways to increase the output of a pickup using it for pole pieces.
1. Use smaller wire so that you get more in turns the same space.
2. Use a pole piece with higher permeability.
The first results in the output increasing proportionally with the increase in the number of turns, but the inductance increases with the square of the number of turns, limiting the usefulness of this way because of the loss of high frequencies. The second results in the output and the inductance increasing at about the same rate. So I think the only reason to use CuNiFe as a pole piece is if you really have to machine it to make a screw. And you do not.
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Post by gckelloch on Apr 23, 2023 23:56:54 GMT -5
...and I don't think Bill would have approved of the presentation. These pickups are almost on the level of the original Micro-Coils, but with higher inductance, lower efficiency, and the benefit of a much higher price tag . The advantage of the screws is for string output balance and lower to upper harmonic balance without the high freq loss from Steel screws. It makes more difference with thinner wire coils, but it even matters with my GFS P90. Lowering the coil and raising the pole screws sounds brighter. Not sure I understand the effect of reluctance, but given the large output difference of the Tele neck and bridge pickups (which seems much more than the inductance difference would cause), couldn't it just be that the wider Steel plate draws more of the string flux lines through the coil? Is the Steel plate also thicker? I just mod'd a pair of Filtertron Blacktops for my new build. When I first tried attaching the A4 magnet between and touching the pole screws on the bottom, it affected the field at the top of the screws so there was a null at the center of the screw heads. A screwdriver would pull to the outer edges of the head. I then tried attaching and touching one side of the Steel bars I got (which are thinner than the A4 magnet) to the pole screws in one of the coils. The null on the head also happened in that set of screws. That must have some effect. Maybe it widens the aperture window, if not also weakens the field at the top, which it feels like it does. Moving the bar off the screws decreases the effect. He may just be using the trendy terminology "slow attack" to describe how the weaker magnet affects the transient character. He may not understand what's actually happening, but it has become a common way to describe pickup sound, like the incorrect use of "compression". Bill Lawrence seemed to favor the use of steel poles or blades with a magnet on the bottom, his designs mostly avoided having magnetized pole pieces. I agree that he'd probably not love the design, but he seemed to appreciate diversity, he wasn't devoted to one particular design concept, as a lot of other pickup makers seem to be. You make a good point that these are essentially like AlNiCo poled single coils with adjustable pole pieces, which is a first for the pickup market AFAIK. I tend to prefer flat profile pole pieces to such an extent that I overlooked that benefit. The big difference in output between between the Tele neck and bridge is that one is about 3 henries inductance, and the other is 6 henries. Doubling the inductance from neck to bridge is a huge leap. Similar to a JB Jazz combo, 4 henries with the Jazz, close to 8 henries with the JB. Just as a reminder, the inductance is not the cause of the output, it's just a corollary, as is DC resistance, but it correlates much more closely than resistance, because the cause of high output and the cause of high inductance are closely related, where as the cause of high DC resistance is not closely related. The main reason the base plates don't assist the reluctance path very much, no matter the size, is because the magnetic gap is mostly air. Even with a Jaguar pickup, which has a "claw" shaped steel base plate, it replaces a lot more air than do these base plates, but still, it does not displace enough air gap to have a substantial effect on the reluctance. The best you can do is replace air in the core of the coils, which is what the slugs or screws do, or replace the air between the guitar strings and the coil, and the way to do that is to just have the pickup set very close to the guitar strings. This subject matter relates to inductor design, so if you read about the significance of air gaps in inductor enclosures, it's informative. I understand that he might use incorrect terminology to be relatable, but he's been called a "pickup guru", I think it's fair to set a higher standard here. I know you have been suspicious of claims I've made about BL pickups in the past. Fair enough, but I think it's misleading to say he simply used "Steel" with magnets on the bottom. It implies his designs and use of materials were no different than those of cheap Ceramic-powered Asian pickups, when it is absolutely not the case. It is true that he leaned toward designs with various alloy poles and blades. FI, the MC pole screws were originally a relatively high permeable/low conductance alloy (probably permalloy) until they were inadvertently replaced by the supplier with a non-magnetic alloy, and there are other elements to the design that improved efficiency without undesired inductance increase. It's also true that at least six of his most recent designs employed AlNiCo poles. One design was a HB. At least three have a type of A2, and one has A8. At least three come in several inductances as well as pole-width versions. I think the AlNiCo MC's can also be ordered with staggered poles. His Keystone design had AlNiCo poles of some sort. The NF series are a fairly complex design, and only one of the three models uses 400 series stainless Steel poles, as used in several of his other designs. Regarding the use of thinner wire to get more winds in the same space: more winds of thinner wire are not required for improved efficiency if they are situated within the strongest part of the field from the strings. Evidence that the efficiency of a denser coil can supersede the DCR increase was shown in your V measurement of AlNiCo MC's compared to another AlNiCo core pickup of thicker wire and higher inductance. In my DI recordings of the same guitar with cheap A5 core 42AWG SC's and my original MC's with 46AWG wire, the difference in lower to upper harmonic strength is obvious, along with the slightly lower Q. Back to the topic, the large discrepancy in the given specs compared to the actual measurements makes me wonder if this pickup guru and/or Fender really know what they are doing. The relatively high inductance of the FeCrCo models makes me think he didn't know the alloy would increase inductance that much, and then he didn't think it was worth rewinding to lower the inductance, regardless that Tele bridge pickups don't typically have near that high inductance. Just what did he/they retain from their collaboration with BL on the Fender SCN design? |
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Post by antigua on Apr 24, 2023 11:07:22 GMT -5
Regarding the use of thinner wire to get more winds in the same space: more winds of thinner wire are not required for improved efficiency if they are situated within the strongest part of the field from the strings. Evidence that the efficiency of a denser coil can supersede the DCR increase was shown in your V measurement of AlNiCo MC's compared to another AlNiCo core pickup of thicker wire and higher inductance. In my DI recordings of the same guitar with cheap A5 core 42AWG SC's and my original MC's with 46AWG wire, the difference in lower to upper harmonic strength is obvious, along with the slightly lower Q. Back to the topic, the large discrepancy in the given specs compared to the actual measurements makes me wonder if this pickup guru and/or Fender really know what they are doing. The relatively high inductance of the FeCrCo models makes me think he didn't know the alloy would increase inductance that much, and then he didn't think it was worth rewinding to lower the inductance, regardless that Tele bridge pickups don't typically have near that high inductance. Just what did he/they retain from their collaboration with BL on the Fender SCN design? You get more voltage when you have a higher concentration of winds in the most dense area of flux change, because those turns are connected in series. If you have fewer turns of wire for the same space, the voltage is less but the current his higher. This is the case with the Lace Alumitone, which is but a single turn of "wire", it's high current, which is converted to a higher voltage via transformer. What a normal pickup does with a single component, the Alumitone does across two components. In transformer design, what dictates the step up or step down ratio is the number of turns on one coil versus the others, so if you can cram more turns on one side, it will give you that much of a higher step ratio. What's really interesting about the Alumitone is that it can achieve a higher voltage despite using such a tiny transformer. As for the discrepancy of measured versus stated specs, I've seen that with a lot of their products. It could just be that they started making the packaging before the pickup design was set in stone. I think the Guru label and all of that is just marketing, or course. One thing that bothered me was he said, paraphrasing, - we wanted to see what Seth Lover would have come up with if given more time to experiment with the parts on hand -, basically suggesting that these are like Seth Lover single coils, but just as an example, we know Seth Lover wanted the original PAF to have a solid chrome top with twelve slugs, no screws at all. I think if they were really trying to channel Seth Lover they would end up with a solid topped chrome humbucker. If they said it had to fit in an existing pickup's space, he'd probably have opted for a single coil sized humbucker, enclosed in shielding. |
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Post by ms on Apr 24, 2023 11:42:55 GMT -5
All the flux change inside a loop of wire counts. The wire does not have to be close to the flux. However, if a certain field line is to count, the loop must not be so big that it includes this line returning to the string as well as coming from the string. (This is to avoid cancelation.)
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Post by antigua on Apr 24, 2023 19:17:14 GMT -5
I have these pickups in a Tele, I played with them for about an hour, a few different genres with a drummer. The low resonant peaks, and huge gap between the neck and bridge inductance is very audible. The bridge pickup is quite a bit louder than the neck, with both set about the same distance to the strings. If you are someone who always thinks a Tele is a bit too bright, you'd like these pickups, but if you leave the tone controls at 10, you'll probably miss the top end clarity. I'll admit, I expected them to sound outright bad based on the inductance values, and I'd say they're unique and peculiar, but definitely not outright bad. This makes me curious why Fender made the inductance values so high, I get the feeling the pickups would have worked well enough with lower inductance values / less wire. I've never been a fan of the Little '59 Tele bridge pickup, the inductance seems way too high to me, but my brother loves it, and I've seen them in a lot of Teles. I think the bridge Tele FeCrCo pickup's sound is somewhat similar to Little '59 sound, but not nearly has dark guitarnuts2.proboards.com/thread/7905/seymour-duncan-little-analysis-review , the Little 59 bridge has an inductance of 8 henries and a loaded peak of 1.7kHz, where as this pickup is 6 henries with a loaded peak of 2.2kHz, so this pickup represents something in between the Little 59 bridge and a stock Tele bridge pickup. The Seymour Duncan Quarter Pound for Telecaster set guitarnuts2.proboards.com/thread/7728/measured-electrical-popular-telecaster-pickups is similar in that it's very high inductance single coils, but they're even higher inductance than these, 10H / 1.9kHz bridge and 4H / 2.4kHz neck, and I really did not like that set. This FeCrCo set with its more modest values is much more in keeping with what you'd expect a Telecaster to sound like. ~~~~~ As for the Strat set, I accidently broke the bridge pickup by tightening the mounting screws too much. I somehow caused the PCB base plate to flex, but the bobbin itself is a separate piece of plastic which is held to the base with two screws as seen in the pics, so what happened is that one of the solder joints between the coil's end in the coil former, and the base plate, broke. The screw mounting holes are a tall eyelet style, so when the screws are in there, they wont flex around like they do with vintage fiberboard, they're held rigidly upright. So if you have it in pick guard using both screws, and set it to an extreme angle, like you're tightening up one screw all the way before tightening the other at all, the difference in angles between the pick guard's screw holes and eyelet screw holes in the pickup will put a tension on the PCB base plate and snap the solder joint. The coils are likely 44 AWG, so the amount of tension required to snap that solder join is probably rather low. The really evil thing is, sort of like breaking the coil start on a vintage Fender pickup, is that it means the coil is toast, and the whole pickup becomes a paperweight due to a relatively minor mistake. In this respect the pickups are very delicate, because there's no other pickup on the market I know of where this vulnerability exists. I would bet it could easily happen to a Seymour Duncan Little 59/Rails if not for the fact that the mounting holes are part of the cover, and not the base plate as is the case here, but otherwise they're similar in that they have 44AWG around coil formers that are soldered directly to a PCB base. Not many other pickup designs use a PCB as their base. I called Fender though, and they agreed to exchange the set for a new one, which is great. It makes me wonder if this going to be a common problem for them or not. I think guitarists could possibly break these pickup in future, after they're in the guitar, by over adjusting them. |
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Post by gckelloch on Apr 24, 2023 19:42:29 GMT -5
All the flux change inside a loop of wire counts. The wire does not have to be close to the flux. However, if a certain field line is to count, the loop must not be so big that it includes this line returning to the string as well as coming from the string. (This is to avoid cancelation.) That makes it sound like the distance from the origin of the dipole (if that's the correct description) in the string doesn't affect the output, but it does. BL determined that there's not much point in the coil cross-section being much more than 1/8" square, at least in conventional designs. The Alumitones are a very interesting design. Output isn't really a concern for me, but the gradual high-end roll-off gives them a unique character. The Lace company graciously allowed Becky to make BL's pickups in their building at one point when he was in hospital. Very cool in my book. |
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Post by antigua on Apr 24, 2023 19:57:28 GMT -5
All the flux change inside a loop of wire counts. The wire does not have to be close to the flux. However, if a certain field line is to count, the loop must not be so big that it includes this line returning to the string as well as coming from the string. (This is to avoid cancelation.) Setting aside the string, there's contributory flux change in the pole piece also, if you have a wide coil around the pole piece, then its width will cause an increasingly greater proportion of return flux to be captured and cancelled out. |
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Post by ms on Apr 24, 2023 20:17:29 GMT -5
All the flux change inside a loop of wire counts. The wire does not have to be close to the flux. However, if a certain field line is to count, the loop must not be so big that it includes this line returning to the string as well as coming from the string. (This is to avoid cancelation.) That makes it sound like the distance from the origin of the dipole (if that's the correct description) in the string doesn't affect the output, but it does. BL determined that there's not much point in the coil cross-section being much more than 1/8" square, at least in conventional designs. The Alumitones are a very interesting design. Output isn't really a concern for me, but the gradual high-end roll-off gives them a unique character. The Lace company graciously allowed Becky to make BL's pickups in their building at one point when he was in hospital. Very cool in my book. The law of magnetic induction is correct. BL is not. |
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Post by gckelloch on Apr 24, 2023 21:00:20 GMT -5
What? It's common knowledge that magnetic force weakens with distance. The outer flux lines from the string generally traverse more distance b4 going through the coil. Would they then not contribute less to the total output? Am I misunderstanding something?
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Post by antigua on Apr 24, 2023 21:52:27 GMT -5
What? It's common knowledge that magnetic force weakens with distance. The outer flux lines from the string generally traverse more distance b4 going through the coil. Would they then not contribute less to the total output? Am I misunderstanding something? I think what he's describing is that if you have so much flux through a loop, it will create the same voltage regardless of whether the loop is narrow or wide, because the voltage is proportional to the change of flux through the area of the loop, no matter the size of the loop. Imagine the flux is a fish and you have a fishing net, you capture one fish no matter how big the net. From the perspective of a guitar string, it doesn't matter much if the coil is big or small, because the guitar string's return path is very wide, wider than the coil. But that's just the guitar strings, they are a distance away from the coil, where as steel pole pieces are also magnetically active, and they're particularly close to the coil, and pole pieces have a tighter return path than the guitar string. A P-90 or Jazzmaster's wider coil might actually have a better efficiency, because they might capture more flux of the guitar string that is of just one polarity. In the case of a P-90 though, it has steel screws that are magnetized, and it seems to me that the P-90 coil is so wide that the flux change from the screws is probably cancelled out over the wider area of the coil, but they still serve a purpose of magnetizing the guitar string. It's probably the case that the two things counterbalance; as the coil gets wider, more voltage comes from the guitar strings, but less voltage comes from the screws, and vice versa. |
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Post by gckelloch on Apr 24, 2023 23:24:14 GMT -5
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Post by antigua on Apr 25, 2023 0:20:47 GMT -5
Maybe BL's conclusion just pertained to pickups with high permeable poles, although he did think a lot of the coil in most pickups is wasted. If the coil is tall, and the core is not highly permeable, then the bottom portion is wasted. That's the case with AlNiCo single coils, because it has low permeability, so not much flux change is carried to the lower reach of the coil, but if the coil has steel poles, like a cheap import single coil, then the steel pole piece carries the flux change down throughout the entire coil, and that's a more efficient design, even though it's associated with cheap import guitars. I don't think Fender made their singer coils tall for electrical performance reasons though, but because the AlNiCo poles had to be a certain height relative to their diameter, it also allows the pickup's heights to be more adjustable, and probably make winding the bobbins by hand much easier. Gibson pickups benefit from steel poles and screws, but they also tended to use flatter coils. All around it seems that Seth Lover, Bill Lawrence and whoever was working on pickups at Gibson had a better understanding of all that than Fender. Gibson also had a big machine to wind their coils, instead of hiring Latina seamstresses to do it by hand. Ray Butts of Gretsch also seemed to have a great understanding of pickup design as well. Leo Fender seemed to be more inclined with amplifier design. The Strat and its vibrato system are still industry standard to this day, but several people worked on that besides Leo Fender. He tried to improve on the Strat with the Mustang, Jaguar and Jazzmaster, and largely ended up with guitars and pickups that perform worse. |
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Post by gckelloch on Apr 25, 2023 0:57:09 GMT -5
BL thought highly of Ray Butts. He said he knew Leo Fender, and that he thought Leo's real genius was in finding the right people to do what he couldn't. Like you said, the wider coils of the JM pickups may have increased efficiency with the short A5 poles. I don't consider them inferior to the thinner coil models, but that Jaguar vibrato system is whack.
It still seems like more of the total winds up closer to the strongest magnetized section of the string would be the most efficient thing. Even if flux lines are drawn down more though a taller coil, don't they still weaken with distance? The MC's do have strong output for the inductance level, and the lowest noise of any true SC I know of. Maybe S/N was the goal more than output.
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Post by antigua on Apr 25, 2023 1:24:34 GMT -5
This is good stuff right here. I can't find any permeability or resistance values for FeCrCo, but his plot indicates that FeCrCo 5 has a rather high resistance, and a low permeability, but FeCrCo 2 has a low resistance and an especially high permeability. I don't know much of anything about FeCrCo 2 and 5, but based on the fact that the Tele bode plots show ordinary Q factors, it's looking more like the FeCrCo 2. Tim Shaw says the FeCrCo was a "proprietary blend", so it might not conform to either of the FeCrCo's shown in this plot. I guess the foundry that makes the magnets can give the customer any frankenstein alloy they might want.  I didn't know the WRHB has a steel base plate, that explains why Fender added them to these CuNiFe single coils, even though they seem superficial. As for the baseplate, he says " The results are shown in Figure 3. As the data show, the single biggest influence on the pickup inductance (other than the coils themselves) is the steel plate, increasing the inductance of the assembly by almost 25%." He seems to be under the impression that inductances causes output, so that if you increase the inductance 25%, then you get some bump in the output, but the voltage is determined by flux change though the coil, as caused by the guitar string, which is a fact that he even mentions in his article. Even though the coil itself is close to the base plate, the moving guitar strings are not close to it. It's the same thing as mentioned above regarding the Fender single coils, a tall Strat bobbin might give you 2.5 henries of inductance, but a lot of that bobbin is physically far away from the guitar strings, so the 2.5H inductance becomes a broken promise in terms of equating the inductance with the resulting output. Those base plates are in effect the same as having a portion of coil that is far from the guitar strings; it's there, it makes the inductance higher, but it doesn't contribute to the output with equal proportion. Put another way, if inductance increased output by itself, you could put an inductor in series with the pickup and it would increase the voltage, but that doesn't happen, it will instead lower the frequency at which high end roll off occurs. The more likely reason, I'm 95% certain, that Seth Lover put the steel base plate there is it increase the stability of the CuNiFe, they called those "keepers", and it's what the PAF has one, but it's not a bar, it just abuts the bar magnet, but since the CuNiFe pole pieces stand on end, the steel keeper has be attached to the underside, like a Tele bridge pickup. And in that sense, any extent to which the base plate increases the inductance is more of an unwanted side effect, it's killing high end while giving you nothing in return. |
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timtam
Meter Reader 1st Class
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Post by timtam on Apr 25, 2023 2:22:44 GMT -5
I've heard the original WRHB base plate called a 'reflector' plate (can't recall where, or whether that might have been a notion from the time the pickups first appeared, or a more recent descriptor). It's just called a 'base plate' in the original drawing below (from Duchossoir tele book p61, where the copy is just as bad as it looks below).
It doesn't seem to perform any obvious structural role in the pickup (original WRHB below), so seems to be there for other reasons.
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Post by gckelloch on Apr 25, 2023 2:58:19 GMT -5
It may also just be a convenient way to ground the poles. Yeah, I think the good doctor is assuming more about Mr. Lover's intent than was there. The wide bobbins are probably just because his PAF's had wide bobbins.
I'm pretty sure Dr. Lawing knows inductance doesn't correlate to output. The paragraph above fig. 6 explains how the Steel plate increases efficiency via strengthening the field and drawing lines more into the coils, as well as increasing inductance. Fig. 8 shows that very high core permeability could actually eliminate any signal generation within the center coil sections.
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Post by antigua on Apr 25, 2023 10:39:06 GMT -5
I've heard the original WRHB base plate called a 'reflector' plate (can't recall where, or whether that might have been a notion from the time the pickups first appeared, or a more recent descriptor). It's just called a 'base plate' in the original drawing below (from Duchossoir tele book p61, where the copy is just as bad as it looks below).
It doesn't seem to perform any obvious structural role in the pickup (original WRHB below), so seems to be there for other reasons. Thanks for those details. Tim Shaw said in the interview that he was trying to imagine CuNiFe single coils as Seth Lover might have designed them at the time with the tools on hand, and that's reason enough to have put the steel plate on the new models. The thing about CuNiFe or AlNiCo having a low permeability is that the reluctance across those allows will be high. The steel base plate would have a low reluctance path, but it doesn't seem to be helping to connect the strings to the coil, given the high reluctance in between them. It's being thin and having holes for the CuNiFe to pass through makes it look like it wouldn't be very effective as a keeper, but keepers are not necessary either, as Strat pickups and a lot of others, do not have a keeper. It's a real mystery to me. It's possible that not much prototyping was done, and that the steel baseplate was added to the spec for good measure, without testing to see if it made an impactful difference on the output or not. |
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Post by antigua on Apr 25, 2023 11:02:00 GMT -5
It may also just be a convenient way to ground the poles. Yeah, I think the good doctor is assuming more about Mr. Lover's intent than was there. The wide bobbins are probably just because his PAF's had wide bobbins. I'm pretty sure Dr. Lawing knows inductance doesn't correlate to output. The paragraph above fig. 6 explains how the Steel plate increases efficiency via strengthening the field and drawing lines more into the coils, as well as increasing inductance. Fig. 8 shows that very high core permeability could actually eliminate any signal generation within the center coil sections. Tim Shaw claims Seth Lover made the bobbins more substantial in order to offset the fact that CuNiFe had low permeability, because the PAF had high permeability steel slugs. Don't know if that's true, but it's a claim. The coils didn't have to be larger by that logic, they just have to have more turns on them, so if you figure 42AWG was cheap and available, they'd have to have a larger bobbin to get more turns of 42 AWG on there. |
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Post by aquin43 on Apr 26, 2023 3:50:45 GMT -5
To return to the original subject: the Creamery in the UK have for some time made a single coil FeCrCo pickup that seems to behave very much like a typical strat pickup with a high Q and similar sensitivity but with adjustable poles.
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Post by antigua on Apr 26, 2023 10:13:06 GMT -5
To return to the original subject: the Creamery in the UK have for some time made a single coil FeCrCo pickup that seems to behave very much like a typical strat pickup with a high Q and similar sensitivity but with adjustable poles.
Thanks for drawing attention to that, I had forgotten all about that, but it's definitely worth mention in relation to these pickups. The Creamery is a really impressive pickup maker. They seem to have no problem fabricating lots of custom parts for very unique and vintage style pickups, and you see other pickup makers talk about what great lengths they had to go to in order to accomplish the same thing, including in this case, Tim Shaw saying he had been working on CuNiFe single coil designs for three years. I mostly try to stick to cheap pickups, or pickups that have a lot of interest in the forums, because it is a lot of fun comparing notes with other guitar players about how much they do or don't like pickups. The Creamery looks like a really amazing company, but for some reason they seem to fly under the radar on guitar forums. The fact that Fender made these pickups is a big reason I did buy them, because spec-wise I expected not to like them very much. Everything Fender does gets a lot of press. One of these pickup broke when I was installing them, and Fender customer service sent me a prepaid return label within minutes, and new ones should be here pretty quick I imagine, but when dealing with a company in the U.K., I figure we're probably talking a month turn around time minimum. Having the $300 spent on the pickup set hang up in the air until it gets sorted out is kind of nerve wracking. I actually had to return pickups to Bare Knuckle Pickups back in 2015 or so, and that was a rather unpleasant experience, they threatened not to refund me because they claim the pickups were damaged in transit because I hadn't packed them well enough, after having eaten the cost and wait time involved with shipping. I don't think I've ordered any pickups from the U.K since. |
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