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Post by antigua on Apr 6, 2023 17:29:58 GMT -5
I would use 500k pots with any pickup that is mostly made of steel parts, 250k is best paired Fender AlNiCo poled pickups. The Q factor of rail pickups are on the low side due to eddy currents, and this is true regardless of whether the pickup is wired series or parallel. If you start with 500k pots, you can get the same sound as with 250k pots by rolling the town down to around 8.
If you find that parallel mode is always too bright, 250k pots might be more idea in that case, but if you have a series/parallel DP/DT push pull, I don't think there's a way to have 250k only in parallel mode, using a resistor. Although something else I didn't mention is that my three '59 bridge Strat used three Fender S-1 switch knobs, and those are 4P/2T, so you could have it to where a resistor knocks the 500k pot down to 250 with a Fender S-1 switch, but they cost about $55 a piece when you add up the switch and the plastic knob. One of those things where you have to spend the money because there's no cheap version from China. That I know of.
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Post by antigua on Apr 5, 2023 21:19:00 GMT -5
Antiqua, Great info as usual! 1. I happen to have a Strat copy set up with the 'Everything Axe' pickup set, so can certainly rewire it to have parallel/series for each pickup. No, it will not be as perfect as your 3 x Little 59 bridge pickup wired parallel/series, but may approximate what you uncovered, albeit it more imperfectly -- plus give me more reasons to use that guitar! 2. I can also (another guitar) buy 3 higher output blade pickups (example from Fleor) and do parallel/series to better replicate your 3 x Little 59 bridge pickup guitar experiment. If so then I ask: -Is it better to get the version with the ceramic magnets (like the Little 59) or the Alnico version they also sell? I think there may be trade-offs when shuttling between series and parallel depending on the magnet type in terms of harshness/sweetness, and since the resonant peak is not listed...and since I worry about harshness that is the reason for the question -The 'strongest' Fleor is listed with a K value between 13-14K, so higher than the 11.7K listed for the Little 59 bridge pickup, so JB jr territory. The other Fleor option is 9-10k which would 'clean up' the sound a bunch in series but would reduce parallel to somewhere between 2.25-2.5k, so that would be the second possibility. The question would be, "which would make the more convincing "Strat" sound in parallel while not being terrible in series?" I was just reading your Chopper review, and it seems you had some success in doing series/parallel there too, and that the Chopper may have been more the 9-10K resistance range. Not sure if this is a good example in terms of this discussion, but I throw it out there as it might be and you can throw that into the mix as needed in terms of how it might guide selecting a Chinese knockoff with the right balance of resistance and magnets to be workable in parallel and series (a compromise I know) guitarnuts2.proboards.com/thread/8502/dimarzio-chopper-analysis-reviewEMG: I had to do an install for a friend (and routed the battery box too). Yup, I think you are right, it can work in both Strat/PAF territory. I think rewiring an everything axe to allow for series parallel on the bridge and neck would be great, maybe even the middle pickup as well. I love the sound of a higher inductance humbucker in the middle of a Strat, it's a lot like the Lindsey Buckingham Turner Model 1 sound. Get the ceramic, no question in my mind. I've tried a couple sets with AlNiCo bars, and it's just too weak. AlNiCo is supposed to have a length to width ratio of about 4:1 for optimal residual flux strength, but with those pickups, the little bar magnet is only about 2:1, so the strength is even weaker than what you'd expect with a full sized AlNiCo PAF. A pickup with an overly weak magnetic field tends to sound / feel weak and mushy, it's a feel thing because it will feel like you're plucking the strings hard and not getting as much bright snap as you come to expect with a regular strong pickup, and part of the "Strat" sound is the snap you get with the strong AlNiCo 5 pole pieces. It's subjective, you might like it that way, but I think there's a reason why most all the blade HBs on the market use ceramic, going all the back to Barden and Bill Lawrence models. If they're cheap enough, it might be worthwhile to buy both and try both, that's the beauty of Chinese pickups. You might be right that a weak magnetic field in the weaker parallel wiring sounds better than when wired in series, but I would doubt it myself, I haven't liked any pickups with especially weak magnetic fields. My pickup journey started when I had to replace some Texas Specials that had somehow become demagnetized in storage. I have a Strat with the DiMarzio Billy Corgan set, and those pickups are really hot, I think 15k-ish, and they sound the most Strat like in parallel. It's a pretty versatile guitar in that it could sound like a typical Strat or a very hot Strat, it just doesn't do the in between thing too well, but I can play a lot of repertoire between "Strat" and "super hot Strat", especially Smashing Pumpkins and other 90's era bands. The split or parallel Chopper was good also, but the Billy Corgan set just comes that much closer making me believe I'm playing a regular Strat. I was playing the Duckbucker Strat tonight, 80's pop and 90's grunge, and I was reminded that if you have an array of pedals, especially a Tube Screamer or a Timmy clone or an optical compressor, you can punch up the signal such that the parallel tone of a mini humbucker sounds perfectly thick. A lot of the cork sniffing only applies when you're plugging directly into an amp like a Fender, without a pedal or anything to push the mids and the gain. I also keep the tone control rolled back a bit, if not for that, the brightness would be much.
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Post by antigua on Apr 5, 2023 9:56:14 GMT -5
Thanks Antigua! Of all the brands you checked, or can extrapolate from, which others might give a reasonable Duckbuster (imitation single coil) sound in parallel mode yet still perform in series mode without getting too dark and wooly, or is that asking too much due to the vastly different resistance and 'H' values when flipping from series to parallel? GFS: - I like their Strat sized lipstick set VERY much and have used these on 3 builds to date. Using the Free-way 10- position switch I find 2 pups combine in series fine too. - Gold Foil Single Coil Pickup set: I tried one set, did not fall in love, but it seems fine overall (the metal foil version may be more lipstick sounding, but who knows) - the Lil Killer Strat pup(6K/6K/10K setup) I like, but due to the Kwikplug, parallel wiring split is not available. In other words I could not try the Duckbuster/parallel setup. - I have a set of the mini humbucker Gretch look "MINITRON" but have not mounted them or tested them yet. Fleor: - I mounted high wind Strat sized rails on a customer's Squier (neck and bridge), but too brash/harsh sounding for my taste. I suspect a lower wind or different magnet (Alnico) would work way better in series mode. In terms of knowing in advance which wind would be most effective in the parallel mode... It may be one of the heavier winds which conversely may not sound so hot in standard series mode.... Do you have an opinion on that? (balancing act for a reasonable outcome in both settings) Donlis: - I like their P90 set. I should play it more to get an idea how much I like it.... I used the Oak Grigsby 4-way switch and the 2 pups in series sound fine too. - I have not tried their traditional single coils (yet) but I liked what you wrote (in another one of your write ups) so I may buy some soon. - Their Twin Blade Rail Strat sized pickups, or their Dual Coil Strat size With 12pcs Pole Screw have mostly really high K and H values, so may sound really dark/muffled, though may open up in parallel mode (any opinion?). The possibly most open sounding of the lot could be the DB01 (7.4K, 4.9H) though it may suffer then in parallel mode and be too thin (but maybe you have an opinion on that) Waah: I have them marked up for purchase in my Aliexpress account, I have not pulled the plug, but thanks for the recommendation. In Strat size, they only have the traditional pups, but I still like those too... The Tele tapping set sounds quite intriguing. Oripure: I don't mind modern production look, but I have not tried these yet. I guess at this point my only question is if a reasonable difference exists between them and the Fleor besides in price. Homeland: Ah a good visual knock off of the everything axe pickup set... Thanks for the warning, I'll stay away from those! My favorite single coil sized blade humbuckers are the lower inductance ones, like the DiMarzio Chopper, or the models that Seymour Duncan and other would designate as a "neck pickup". It's just a sad fact with pickups that in order for the parallel tone to remind you of a good Strat pickup, that you have to have a high inductance in series, seems to be true for full sized and mini sized humbuckers. I have Strat with both hot and cool rail humbuckers, and even the Duckbuckers, in fact I brought the guitar pictured at the top of the thread out of storage to play in our jam later, and I just try to pair up the guitar with songs that will compliment its strength and weakness. I have to admit the Duckbucker is probably more weakness than strength, but I like the variety, it lets me have multiple Strat that don't all do the same thing. I find the Strat with the higher inductance blades that split will to be the most useful, because it can sound like a Strat in parallel or a fire breather in series, it works for a lot of music. The DiMarzio Choppers, and the lower inductance neck pickups, some closest to making good on the promise of a PAF like tone in a Strat, IMO, so I have a good time with that guitar, but to be honest when I want a PAF tone it usually just makes more sense to grab an Epiphone, I have to show my HH guitars some love too. I find those "hot" Strat pickups usually do sound harsh, because they have a lower resonant peak, somewhere between 2kHz and 3kHz depending on the guitar cable or lack of one. It can be remedied by rolling back the tone knob to soften the knee, but then it ends up not being a very clear pickup. Over time I've moved to Strat pickups with a DC resistance of 6k ohms or less, because it ensures that the resonant peak will be upwards of 4kHz, and it feels much easier to control, and sound more like the Strats I'm used to hearing on the radio. It sounds like you bought one of these www.alibaba.com/product-detail/Donlis-High-Output-dual-coil-single_60614681728.html , I bought a fake "everything axe" set with three of those, I made a post about them here www.strat-talk.com/threads/analysis-of-chinese-knock-off-of-seymour-duncan-everything-axe-set.502390/ , I didn't get along with those for a few reasons. One thing you might like is something I did in the early 2000's purely by accident. I went into a guitar store, and they only had three Little '59 bridge pickups, but I was after a bridge and two neck pickups, so I just bought all three bridge pickups because it was what they had in stock, and I wired my Strat so that the bridge pickup was in series, and the neck and middle were parallel, and I had push pull knobs to reverse the series/parallel of any of the three, and that actually worked pretty good. I used that guitar and that pickup config the one time I ever recorded in a legitimate big name recording studio. The Little 59 bridge pickups in parallel were perfectly find neck and middle pickups, but I thought of the pickup situation as a hack since it had three bridge pickups. So, about ten years ago I gutted that pick guard put different pickups in it, which I though should be more ideal, but now I kind of regret taking it apart, because it actually was pretty ideal already. I think it sounded more Strat like than Duckbuckers. All in all Duckbuckers and Little 59's are meant to look more traditional, the sound quality takes a hit due to the poorer magnetic coupling. The closest I've come to having single coils and humbuckers in a Strat is with EMG single coils and the SPC mid boost, it starts with a pretty genuine single coil sound, and turning up the SPL control bumps up the mid range to sound a lot like a single coil sized humbucker, but super quietly. The sound quality is definitely really good, the upside to dealing with a 9 volt battery and more circuitry in the guitar.
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Post by antigua on Apr 4, 2023 22:52:02 GMT -5
Antigua, This is all interesting stuff, and sorry I'm so late for the party! (by a few years!) I too like the Duckbuster, but am only lukewarm about the other 2 pickups in the "everything axe" pickup set by Seymour Duncan. Now I know why -- parallel vs series being a big part of it and what it does to the sound per your analysis. Looks lIke I can crack open that particular guitar and give the 'parallel' treatment to the other 2 pickups and be pretty happy. I can even use some DPDT on-on-on if I want to get fancy and have all combinations... In other news, I also suppose the Donlis, Oripure or Fleur rail (or pole piece type) pickups might react in a similar way, if I can find the right version (they come in several flavor of resistance and magnets). Out of curiosity, have you tested any 'rails /or pole piece type' Strat sized pickups from any of those 3 companies? It would be interesting to see where they line up on all this. I have at least one of each brand in a guitar right now, they're all similar to GFS / Artec, good, with vintage correct performance, but they skimp of the finer details, they look like modern production products. You see things like electrical tape, shielding, vinyl wire, and of course their logo painted on the top, which I've had a hard time removing with solvents and abrasives. BYO, and a newcomer on AliExpress called "WAAAH" pickups, are exceptionally good for the price, very vintage correct, I'd check these out www.aliexpress.com/store/1101844801?spm=a2g0o.detail.1000007.1.280c4e65WPH6SW WAAAH has a red Telecaster set, with a coil tap, which is particularly unique and awesome. On this topic though, you might come across these, avoid them, they're complete trash www.aliexpress.us/item/2251832806331473.html?spm=a2g0o.productlist.main.43.38781cf9swdXDV&algo_pvid=e6c5c5b7-c983-42e4-87a5-6d39e21733d0&algo_exp_id=e6c5c5b7-c983-42e4-87a5-6d39e21733d0-21&pdp_npi=3%40dis%21USD%2153.92%2129.66%21%21%21%21%21%40210217c716806666795091730d0750%2166946612401%21sea%21US%21800019275&curPageLogUid=90Iz4QYp0ILb
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Post by antigua on Apr 4, 2023 0:03:41 GMT -5
I was just referring to the fact that it rolls off the treble. It has the upside of buffering the pickup(s), but you could just use some sort of buffer besides, and use regular tone controls instead. Personally, I use a wireless transmitter when I play, the kind from Boss and Line 6, which removes the guitar cable capacitance, so I get a nearly unloaded resonant frequency that way also. Hi Antigua, have you tried to measure the capacitance of the input of wireless transmitters you own? Do you think cheaper transmitters like from Joyo would also remove the guitar cable capacitance? Yeah I did measure the resulting resonant peak with one unit guitarnuts2.proboards.com/thread/8242/capacitance-line-6-relay-g10 , but I haven't tested all of the ones I have on hand. In general, if they don't specifically state that they include simulated cable capacitance, or have a switch to add line capacitance, then there is no added capacitance, and you basically have a zero length guitar cable. The Joyo model makes no mention of cable simulation, so I'd assume there is none. To my ear, that's what the lower end wireless units tend to be, bright and clear. I have to usually roll my tone controls down to six or seven to shed some unwanted high end, which is less of a problem when using a real cable. I can't just turn the treble down on the amp, because I still want my overdrive clipping to have some bite in the treble end. If you wanted to add in your own parallel capacitor, it would be a pretty easy mod, you just gave to put about 470pF across the circuit. Like you could get a sin inch male to female 1/4 extension cable, put it in between the wireless unit and the guitar, and solder the capacitor to the male or female connector, inside where the cable is soldered to the jack. It would be like a virtual 10ft cable.
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Post by antigua on Mar 14, 2023 9:54:34 GMT -5
Hey tell me about your model. I'm trying to model 2 single coils in series in Spice and I'm not sure how you got the two sources working. It's unintuitive, but the AC sources have an AC amplitude of 0.2, although it doesn't matter what the value is here, and then you click the running man icon at the top to start a simulation, select the "AC Analysis" tab and then input these values, which make sense for audio analysis and give decent resolution of the response plot, and click "OK" and it will output "ac lin 500 10 20000" into the schematic somewhere. When you click the running man icon a second time, it will process the plot, you have to click on a node in the schematic to see what the response is at that point. Clicking on the resistor that signifies the amplifier input makes the most sense in this case.
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Post by antigua on Mar 13, 2023 12:40:26 GMT -5
The EMG 81 and 85 should have nearly the same curve, the only difference afaik is ceramic versus AlNiCo magnets, and the response is dome shaped when plotted out, with the top of the dome being in the area of 2kHz, so 1.87kHz could be about right. Given the low Q factor and the dome like profile, the resonant peak of an EMG isn't as significant as it is when comparing passive hi-Z pickups. When people say EMGs have a modern sound, that dome like response curve is likely to blame, and I think EMG has newer models which I haven't looked at, which more closely mimic as passive high Z pickup, and it would be interesting to observe the resonant peak of those pickups, to see what sort of passive pickup spec they aim to sound like. Wait, I don't understand. From the below graph, should I assume the resonant freq of EMG 85 is 643Hz instead of 1.87k? Thanks. Technically it's at a peak around 643Hz, but it's rather flat, from 200Hz up to almost 2kHz.
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Post by antigua on Mar 12, 2023 14:55:59 GMT -5
Thanks antigua. Another thing worth mentioning is that, on the emg website, the emg 85 has a resonant freq of 1.87k, which is very far from what people measured here. How do you think Emg is measuring their pickup so that the number is so different? The EMG 81 and 85 should have nearly the same curve, the only difference afaik is ceramic versus AlNiCo magnets, and the response is dome shaped when plotted out, with the top of the dome being in the area of 2kHz, so 1.87kHz could be about right. Given the low Q factor and the dome like profile, the resonant peak of an EMG isn't as significant as it is when comparing passive hi-Z pickups. When people say EMGs have a modern sound, that dome like response curve is likely to blame, and I think EMG has newer models which I haven't looked at, which more closely mimic as passive high Z pickup, and it would be interesting to observe the resonant peak of those pickups, to see what sort of passive pickup spec they aim to sound like.
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Post by antigua on Mar 11, 2023 21:21:56 GMT -5
I was just referring to the fact that it rolls off the treble. It has the upside of buffering the pickup(s), but you could just use some sort of buffer besides, and use regular tone controls instead. Personally, I use a wireless transmitter when I play, the kind from Boss and Line 6, which removes the guitar cable capacitance, so I get a nearly unloaded resonant frequency that way also. Thanks for the reply, antigua. That makes sense. Except for this active tone control, is there other product can act as a buffer in the guitar? Something like this reverb.com/item/1792639-creation-audio-labs-redeemer-transparent-guitar-output-buffer-install-version
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Post by antigua on Mar 7, 2023 6:53:02 GMT -5
Hi Antigua, great information! From the plot, I see that the VLPF retained the high frequency signals and flattened the peak. In the past, I have tried 1M vol pot without tone pot for both single coil and humbucker. While this wiring retained more high frequency signals, it also makes the resonant peak too high and the treble harsh, I believe. You mentioned what VLPF does can be accomplished by passive circuit, could you elaborate on that? I am not aware of a way to retain high frequency signal while tame down the peak like what VLPF does here. I was just referring to the fact that it rolls off the treble. It has the upside of buffering the pickup(s), but you could just use some sort of buffer besides, and use regular tone controls instead. Personally, I use a wireless transmitter when I play, the kind from Boss and Line 6, which removes the guitar cable capacitance, so I get a nearly unloaded resonant frequency that way also.
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Post by antigua on Feb 19, 2023 20:38:26 GMT -5
Color me skeptical that the insulation stretches along, but I could believe both the copper wire and the insulation mutually stretch under higher tension, I'd go so far as to say, how could they not?
I don't think there would ever be a revised P-Rails because I wouldn't be surprised if they never even made back the investment on the custom hardware that pickup required, but I was surprised that they didn't make high or low inductance, or ceramic magnet variants, as they do with a lot of their PAF type pickups.
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Post by antigua on Feb 19, 2023 16:26:34 GMT -5
The biggest reason the rail coil capacitance is high is probably because the coil is tall and thin. I've learned since that flat coils, like a Jazz Master or P-Bass coils, have a lower capacitance, because the electrical gradient from the coil start to finish is spread over a wider area, where as with a tall thin coil, coil start and finish are close, and in the case of the rail, maybe only a millimeter of coil thickness. The farther apart the two sides of the circuit are, the lower the parasitic capacitance will be in between. The Little '59 and Duckbucker measurements also showed high capacitance guitarnuts2.proboards.com/thread/7995/seymour-duncan-duckbucker-analysis-review " rel="nofollow" target="_blank">guitarnuts2.proboards.com/thread/7905/seymour-duncan-little-analysis-review guitarnuts2.proboards.com/thread/7995/seymour-duncan-duckbucker-analysis-review , though not as high as 600pF. The finer wire like 43 and 44AWG used in the rails and mini pickups usually shows a higher capacitance. I'd guess that thinner magnet wire also has a thinner insulation layer in order to keep the overall thickness of the wire smaller. A JB has about double the capacitance of a regular PAF, even though the coil geometry is about the same, which suggests the wire itself is to blame. If the coil start is "hot" and the metal rail is grounded, that will also make the capacitance higher than if the coil end is "hot", since that puts the hot and ground side of the circuit side by side, the inside of the coil and the rail it's wrapped around. For the blade to be counted towards the capacitance, the shielding would have to be connected to the alligator clips of the LCR meter or testing device, but I don't remember if I had the shielding wire included when I measured it, those are details I should have made note of at the time. I should pull the P-Rails out of the drawer and check.
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Post by antigua on Feb 17, 2023 17:12:22 GMT -5
The field of a permanent magnet is not a function of the material's permeability. Permeability is a term relating to applied magnetic fields. With steel, the residual flux is low and the permeability is high, with ceramic or neodymium, the residual flux is high and the permeability is very low, and when you have a pickup with a ceramic magnet and steel pole pieces, then you take advantage of both properties, but with both being in different physical space, the magnet on the botton and the streel as the pole pieces. With AlNiCo pole pieces, a modest permeability and modest residual flux both coexist in the same material, in the same location, almost as if the steel and ceramic were mixed together in one place. Some of the domains in the AlNiCo are rigidly aligned and some are free moving, the rigid domains are what give it a residual flux and determine its coercivity value, the free moving ones give it permeability. The different grades of AlNiCo will result in more of one characteristic than the other, for example AlNiCo 2 and 3 have a higher permeability but a lower residual flux, where as AlNiCo 5 or 7 or 8 are the other way around.
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Post by antigua on Feb 16, 2023 13:48:22 GMT -5
The distances are given in mm, so I converted to Tesla and m then the result back to Gauss. If I set Br as 3000 I get exactly the table numbers. How are you handling mm if you use Gauss? If you mess around with the WT10-A you find that the Gauss varies a lot depending on where the probe is placed. That table implies that the probe is 1mm above the center of a pole piece. Usually AlNiCo is sized to be about four times longer than it is wide, because it achieves the highest Br with that geometry, so even though they don't describe the conditions that led to the Gauss value, their numbers are consistent with what the WT10-A will show. The WT10-A give milliteslas, you convert that to Gauss by just multiplying mT by 10. Why the math doesn't work out, I have no idea, but the math will be wrong sooner than reality will be wrong.
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Post by antigua on Feb 16, 2023 12:15:12 GMT -5
That's what I was going to say too, but I'll add my own wording... the reason the magnetic field in the string is not an exact refection of the magnetic field as it would be in the air is because once the string is magnetized, each atom or magnetic domain in the string forms its own magnetic field, which effects the immediate neighboring atoms in the steel, causing a chain reaction. The higher the permeability, the stronger the chain reaction will be, because what permeability is, is a description of how willing magnetic domains are to being re-oreinted by an ambient magnetic fields, where ambient magnetic fields are both external field as well as the fields of their immediate neighbors in the material itself. I suspect the math is complicated because of that chain reaction, which is why when you model a magnetic model with FEMM software www.femm.info/wiki/HomePage , it takes a while for it to process, it has to do a ton of processing work to create a graphical depiction of the flux path, and in only two dimensions, let alone three.
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Post by antigua on Feb 16, 2023 10:46:30 GMT -5
asher, it's going to make a person upset if you say that your not understanding of what they are saying, and/or the fact that they can't state what they're saying with pure maths, must mean they're wrong. We're not Einsteins obviosuly, but Einstein wasn't big on math either, because at the end of the day, math has to be made to conform to the world around us, not the other way around. But if you like math you're going to love this drive.google.com/file/d/1EkaP9gMzT-MvFHL8E9Ox6KjHjS8NHD3C/view?usp=sharing I'm a hands on type myself, I have a bad habit of getting stuck in a way of thinking and I have to see directly contradictory evidence in order to get me out of that rut. I recommend this magnetometer in particular www.amazon.com/Homend-Gaussmeter-Surface-Magnetic-Function/dp/B07CNRWDJZ/ , it would make the gauss question clear instantly, as well as polar orientation. You can get a vintage style Strat pickup for just $15 www.amazon.com/SSA-12-Vintage-Staggered-Alnico-Electric/dp/B0B3QH4F9H/ For testing things out related to inductance and capacitance, this meter is really great www.amazon.com/Conversion-CD-ROM-5000-Handheld-Protection/dp/B08TV2KN1T , and you can see how the inductance changes if you replace the AlNiCo with steel slugs, or just air, and this relates directly to reluctance, because lower reluctance means higher inductance. The magnetized guitar string has a null in the middle, over the pole piece, you can see how that must be true by using that WT10-A meter, a magnet and a steel screw to act as the model of a guitar string, you can see that the screw has the same polar face on the ends, which means that the magnetic vectors have to be pointing towards the center, at the center. I find that seeing things first hand helps me a lot.
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Post by antigua on Feb 15, 2023 23:00:00 GMT -5
Does anyone have any measured voltage data from a pickup with a known number of turns and a known magnet as a result of string pluck? The voltage output from a string pluck varies widely based on lots of factors. The transient voltage is usually much stronger than all that comes after, and the transient will vary a lot based on how hard the string is plucked. There's lots of other variables besides. This web page claims to have some experimental data if you're looking for a ball park sound-au.com/articles/guitar-voltage.htm
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Post by antigua on Feb 15, 2023 22:53:33 GMT -5
asher, I think you asked why the string isn't strongly magnetized directly above the pole piece, in some post on the first page. Even though the magnetic field itself is strongest in the middle. The reason is because the guitar string becomes like two magnets, one magnet being on either side of the pole piece, each half with same polar face pointing away from the pickup, both N or both S. Therefore, in a guitar string, you have N and N or S and S facing each other right in the middle, and that creates a null in the center, where the magnetism cancels out.
The same thing happens with the six screws in a PAF, the screws are long and stick out the bottom of the pickup. Inside the pickup housing, the screws intersect with the bar magnet at about the half the length of the screw, the screw magnetizes in two directions so it will read south on the top of the screw, and south the bottom of the screw, and the two north ends are right in the middle, creating a null right there in the middle. The interesting thing about that is that if you cut off the bottom of the screws, the pole pieces will have stronger magnetism at the tops of the pole pieces, since the bottom half of the screw counteracts the magnetism of the top half of the screw.
In magnetic modeling, they talk about "guiding the path of flux" and such, but that's not really how magnetism works, magnetism is just vector math, and "flux" is the sum of all the vectors in and around whatever is being studied. Sometimes when things get confusing, I think it's easier to just remember that it's vector addition in air and in permeable material.
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Post by antigua on Feb 14, 2023 18:22:46 GMT -5
Regarding reluctance, it shares a lot in common with considerations of transformers eepower.com/technical-articles/magnetic-circuit-properties-understanding-reluctance/ if you think of the moving string as a primary and the pickup coils as secondaries, and in both cases a higher reluctance means a poorer "coupling coefficient" or "K", where K=1 means the coupling is perfect. Since a guitar pickup and string have mostly air around them, K would be much closer to zero than one. Since a transformer is not mechanical, K is a fixed value, but in a pickup, K changes a little as the guitar string moves, the change of K implies that the associated flux pattern is changing also, everywhere in space, and the coils are positioned in a place where they can see the greatest amount of whatever change is occurring, and music is made. But because a transformer is static and more ideal, it's easier to calculate what should happen, as compared with a pickup, where everything is non ideal compared to a transformer.
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Post by antigua on Feb 14, 2023 12:53:01 GMT -5
Antigua: The air gap between the string and the pole piece is a small part of the total air gap around the path of varying flux. The gap is so large that the main purpose of the variable reluctance method, simple solution for certain simple problems, does not apply. One of the conditions for a simple solution is that the air gap in the nearly complete path of permeable material must be small enough so that the fringing field (lines curving outward at the edges of the gap) is small. In the case of a pickup, the fringing field dominates, and other methods of solution are better. I realize the air gap is small, but the voltage output is small, and you have to have ~7000 turns of wire to sum up a usable output voltage. My understanding is that reluctance and resistance are similar ideas, so let's say the string near the pickup is resistance reluctance A and the string far from the pickup is resistance reluctance B, then as the string moving gives a magnemotive force of A - B, and this difference is where the voltage comes from in the coil. I would think that even if you modeled the string as a permanent magnet that moves back and forth, that the delta of flux through the coil that produces the expected voltage would compute out the same as you had looked as it as reluctance model, but the thing that makes the reluctance model appealing is that it automatically accounts for the contribution of the permeable core in the pickup, since you're looking at all the permeable elements at once, and how the sum reluctance between them changes when the guitar string is moving. To the question of the string saturating, I think that if you put a neodymium magnet beside the string while it moves, it increases the output a bit more, wouldn't that indicated that the string was not at the peak of it's BH curve?
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Post by antigua on Feb 14, 2023 1:38:44 GMT -5
You can control the Q factor with the tone pot. If you put in a 1 meg pot, that gives you the most range of high to low Q. If the Zexcoil has neos in the cores, then the Q factor will be supremely high by their nature unless the maker soldered in a resistor, to knock the Q factor down within the pickup's housing. If the Zexcoils sound sharp in a was that the tone control can't resolve, I'd suspect maybe it's something else, like a low inductance paired with the strong neo magnets, opening up a lot of treble aside from Q factor. If you have a strong magnet, it causes asymmetry in how the guitar string moves, causing an increase in harmonic amplitudes over the pickup that is causing the pull. That's why A5 poles sound so sharp, compared to anything else.
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Post by antigua on Feb 14, 2023 0:57:08 GMT -5
Variable reluctance includes the air gap between the string and the pickup, and the air gap changes as the string moves. The saturation of the string would just be one factor, and you'd have to account for hysteresis, the magnetization won't exactly rise and fall in accordance with movement. Either way, the velocity is the same, but variable flux in the non saturated guitar string would add a distortion, a harmonic.
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Post by antigua on Feb 11, 2023 20:07:58 GMT -5
I did make a dual selector Strat with split pickups, guitarnuts2.proboards.com/thread/8810/bipolar-pickup-details I used "Bipolar pickups" by S&S Winding www.facebook.com/BiPolarPickups/ , the prices were fine. They tried to push a loaded pick guard that enforced split combinations so that you'd never get cancellations in between G and D poles, and it gave you a unique sound, but I really wanted the whole bag of tricks, so I set it up with two switches like you see. The really cool thing is that I was able to have a global tone control as well as a tone control for just the EAD strings, which offers even more possibilities of sounds. The end result is not as shocking as you'd expect. It comes across more like an EQ control, changing the overall balance of bass or treble depending on where you set the switches. That's an upside of a traditional setup, having all neck, bridge or middle, because when you blend them, the harmonic distinctiveness of a given position gets washed out. I think you'd get a bigger sonic effect if you sent the outputs of the two sides to different guitar amps and had a stereo effect. Playing a solo with split sounds is interesting, you can get the sound of one pickup while riffing on the EAD and the sound of another when you switch to the GBE, and get different voicings as if you were switching the pickups selector in the middle of the guitar solo. At the end of the day I think you'd gravitate towards a traditional control set up for ease of use, that's how it always seems to play out. As far as how the G&L-like split pickups would sound, if you watch a good demo of a Comanche, like this one is right to the point: you can see how it will sound. I'd say that it mostly sound like a Strat with the sound of the middle pickup mixed into the whole sound. If you are the sort of person who doesn't like the middle pickup of a Strat, you might hate hearing that timbre sprinkled all over the guitar, but if you like the Jaguar and Jazz Master sound, it brings more of that middle area tone to the bridge and neck pickups. Personally, as time goes on I just want a Strat to sound like a Strat and if I want a guitar that sounds like something else, I just pick up something else. I guess I want my eyes and ears to be in agreement. If the goal is noise cancellation, I think the EMG active sets for Strats is the only way to get real Strat sound with zero noise and no compromise to the tone. Pickups like DiMarzio Areas have a good reputation but IMO, it's a "best among the worst" situation.
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Post by antigua on Feb 4, 2023 20:13:54 GMT -5
A member asked for more specifics about how to test pickups with the Analog Discovery 2, so here are step be step instructions. The process is basically identical to the Velleman guitarnuts2.proboards.com/thread/7775/pickups-resonant-peak-usb-oscilliscope , you have two input channels, A and B, a generator output, all of which are BNC connectors, a 1 meg ohm resistor and the pickup under test. 1) Connect two probes to CH1 and CH2, and a test lead with alligator clips to the function generator output of the Analog Discovery 2. 2) Join together the tip of the probe to CH1, one side of the 1meg resistor, and the positive lead of the pickup 3) Join together the tip of the probe to CH2, the other side of the 1 meg resistor, and the hot (usually red) lead alligator clip from the function generator cable. 4) Join together the grounds of everything, the CH1 and CH2 probes, the ground (black) alligator clip from the function generator cable, and the ground side of the pickup under test. 5) Make sure the probes are set to 10x Then you have to open the Waveform software, and click "Network" to create bode plots, and select start and stop frequencies that are practical for pickups, like 10Hz to 20kHz, and adjust the vertical scale on the right side to get a good visual of the plot that's created of the pickup's impedance. If you click "View" at the top, and then "Cursors", a panel opens below, you click "+ Normal" to add a cursor, and then you can slide it to the resonant peak, and it will display the frequency, amplitude and phase: Here's a picture of the setup I have, with circles around the important connections: Now for the integration part, you can have it perform math on the fly and show the resulting graph in real time: The steps to get this working.. 1) In the right hand column, uncheck the "Phase" to remove it from view, and check "Custom One" to place it in view. 2) Click on the bottom box of "Custom One" to open the window where you can enter a math operation to be applied, and enter: ( Gain / sqrt( 1 + sqr( Freq ) ) ) This input is actually a function wrapper where the inputted line is returned, and the function arguments are Freq, Gain, Phase, Real, Imag, THDN, THD, HD#, so it's making use of any of those variables and returning the outcome. I'm not entirely sure is that formula is correct, I don't even know where I found it, but it seems to work-ish. aquin43 posted some other equations but I honestly don't know how to apply them to the function wrapper that we have to work with. 3) The plot will end up being very small, so the Top and Bottom values of Custom One have to be adjusted to small values in order to see the resulting graph. You have click and drag the Y-axis markers on the left and right side of the graph move move the data plot into view. You can see in the screen shot I have Top as 0.00002X and the Bottom as 0.00000064 X. TBH, you have to fiddle around with it to get the best result. And I think that's about it.
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Post by antigua on Jan 27, 2023 21:24:18 GMT -5
I think I prefer Bardens for a quiet Telecaster, they're the basic steel blade design with a ceramic underneath, which you can get from a variety of makers, cheap and expensive alike, provided that the inductance is on the lower end, and not trying to be a "full sized" humbucker sound, such as Hot Rails or Choppers. I have a feeling I'd like EMG single coils for Telecaster a lot also, they're great in Strats, but I haven't got around to trying it out. You forget they're not regular single coils and you say to yourself, "where is that hum I'm used to hearing in between songs?"
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Post by antigua on Jan 17, 2023 23:06:21 GMT -5
What an awesome video. This is legit the best video I've see on the subject. If you're making these at production scale, some of these steps might take a little too long, but if you make small quantities of pickups, the attention to detail and quality work is what it's all about.
I wonder how Abigail Ybarra handled this issues while winding single coils for Fender. I know they don't bother with the kapton tape or gluing the magnets. I'm not sure if Abigail Ybarra pressed the flatwork and the magnets together. I would guess not, since it's somewhat more physical than spooling, but then again Fender must have some custom made jigs and tooling that let them press it all together with the pull of a lever.
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Post by antigua on Jan 2, 2023 21:14:34 GMT -5
This is a cool idea. Could it will model eddy currents in metal covers more effectively by having the magnetic lines intersect with the metal cover more like a real guitar string? Some portion of eddy currents are due to the cover, and some the pole pieces, maybe this configuration will place blame more accurately that an exciter that is focused more directly at the pole piece.
Even if the string causes its own eddy currents, isn't that a realistic fact of what would happen with moving guitar strings? Maybe a toothpick could be used to avoid eddy currents if string eddy currents don't belong in the measurement, but guitar strings aren't made of wood.
A big upside also seems to be that the pickup will magnetically couple with the steal string the way a real pickup would, and that might give a more true output measurement comparison between steel pole pieces versus AlNiCo, and other pole piece configurations, as compared to an air core exciter.
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Post by antigua on Dec 25, 2022 2:15:22 GMT -5
I think the magnetic pull is mostly over the two pieces. The pole piece causes magnetization in the string that is like two thin rod magnets (along the string) with like poles facing each other. The field from the string magnetization pointing toward the pole piece is over it as aquin43 has shown, for example, in the model plot here: guitarnuts2.proboards.com/post/104632/thread. But still that's two points of attraction instead of one, so it would bend the string more broadly, like if you were to tug at the string with two fingers instead of one.
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Post by antigua on Dec 24, 2022 4:13:34 GMT -5
Hello Antigua, thank you for the detailed analysis of the qpickups' firebird pickup. Looking at the specs (about 2 Henries, about 6 kOhm, about 4.35 kHz resonance frequency loaded) I would like to know, how different these pickups are from strat pickups like 57/62 or CS 69 soundwise? The plot makes me imagine a sound "in the ballpark" of these classic single coil pickups. Or am I wrong? Karl Yeah the biggest difference is certainly how Firebird pickups are positioned in a guitar compared to Strat pickups. This blue space ship looking guitar I have in the pics places these pickups roughly in between where Strat pickups would be, so it's very different for that reason alone. So I'm kind of at a loss, I want to say Strat pickups like the CS 69 are harsher and peakier sounding, but I couldn't tell you if it were the pickups, or the placement of the pickups. The electrical properties say that these pickups have the same filtering properties both in terms of peak frequency and Q factor, so I trust that they sound pretty much the same when listener bias is removed. The two coils also cause some comb filtering that a single coil doesn't have, but the comb filtering is at high frequencies because the coils are very close together, but nevertheless it could impact the "pick attack", for that brief one or two cycles when high frequency is abundant in the signal. To the extent that it's audible, it would soften the pick attack. The two coils also diffuse the magnetic pull over a wider area. The single pole AlNiCo 5 pole pieces pull on the strings in a specific spot, and it induces harmonics when the pickup is underneath the antinode of the harmonic, but since the magnetic field of this pickup isn't as sharply focused, it won't alter the harmonics exactly the same way, but probably still very similar. I measured 850G over both bars, so the overall amount of pull is as strong, if not stronger, than single AlNiCo 5 pole pieces measuring 1050G, so overall I suspect they will sound nearly identical. These also humbuck, single coils don't, and I have got the feeling that people can judge a pickup to sound different than another, just for the fact that there is a lack of noise present.
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Post by antigua on Dec 20, 2022 4:34:56 GMT -5
It might be good to email Seymour Duncan Co. for more info about this, as I'm sure they've had to have some of these come back to them. They should confirm the tell tale signs of a fake, because little details can change between production runs. Like the size of the 4 conductor cable, they might source spools of it from different places to get better prices. I emailed EMG about the fakes and they were somewhat helpful. They've changed so much over the years that Seymour Duncan was even offering a reissue JB from the 80's, an acknowledgement that over the decades little details had changed to the point that the 80's originals were becoming sought after.
I'm surprised at the idea that these are fakes, because the fakes tend to be such shoddy pickups, and it could be said that fake or not fake, those looks like decent pickups with presumably nickel silver baseplates. This reminds me a lot of the Epiphone Pro-Bucker fakes on AliExpress, the major shortcoming with those was that the covers were mixture of brass and nickel silver, and the hue of gold was all over the place. Since these Seymour Duncans in question don't have covers, the biggest point of variability in quality is off the table. It looked much like the fakes were QC rejects and OEM parts that were slapped together by a third party, which would explain why it was a grab bag of quality, rather than a consistent low-quality pickup. The brass covers were probably not OEM, while the nickel silver covers were probably OEM rejections.
I could see something similar happening here, where various parts are source from China and then finally packaged in the U.S., so that a counterfeiter in China would simply have to take the same raw materials and do the finish work on their own, which is where the shoddy looking logo comes in. I don't know if I agree that you can tell the logo apart based on the font details alone, but in the "fake" there is some smearing in the silver paint, and IME real Seymour Duncan pickups have a really precise logo on the top. Suppose the logo is applied in the U.S., or maybe it's applied in China, but these couple be OEM parts that never make it that far along the process, so the counterfeiter as to do the final steps of production on their own, and it comes out worse. They might do this work in a tiny apartment instead of at a factory with all the proper tools.
As for the baseplates, I get the feeling the baseplates are authentic on both, because that's something the copy cats screw up so often so readily, they look more alike here than is typical with fakes. The hole spacing and even the screws look identical, and you usually don't see that attention to detail. The fact that the JB / Jazz / '59 come as OEM pickups in so many import guitars would leave me not surprised to find that parts of the pickups are made overseas, like the guitars they end up in.
Another thing to compare could be the coils, like if you pull back the tape, you might find the fake coils have a polyimide tape on them, as so many cheap pickup do. Drift in DC resistance between 15k and 16k might or might not be significant, DC resistance can vary for a few reasons. Inductance would be a better survey because the authentic version likely has a precise turn count, so the inductance should be consistent, but the fakes would probably have some different turn count and inductance values.
With so many U.S. based companies outsourcing the components, and then doing some final assembly in the U.S., the distinction between real and fake will probably get more blurry in the coming years.
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