Members zeusecho Posted February 19, 2011 Members Share Posted February 19, 2011 So I'm thinking about putting a set of Suhr Aldrich PUPs in my LPC. Is there a difference in the tone between the standard PUP and the metal covered version? Link to comment Share on other sites More sharing options...
Members zeusecho Posted February 19, 2011 Author Members Share Posted February 19, 2011 No love for a stupid question I guess. Link to comment Share on other sites More sharing options...
Members JesusCrisp Posted February 19, 2011 Members Share Posted February 19, 2011 I've heard a lot that covered humbuckers sound less open and a bit more nasal than non covered ones. Sounds kinda stupid, but maybe it really is like that. Link to comment Share on other sites More sharing options...
Members zeusecho Posted February 19, 2011 Author Members Share Posted February 19, 2011 I've heard a lot that covered humbuckers sound less open and a bit more nasal than non covered ones. Sounds kinda stupid, but maybe it really is like that. Thanks, IDK either, but I can't imagine that such a difference in constuction would not alter the tone. Link to comment Share on other sites More sharing options...
Members firejack018 Posted February 19, 2011 Members Share Posted February 19, 2011 I've been told by Bryan of BG Pickups and also Tim of Bare Knuckle Pickups that covered pickups will mute some of the highs. They actually wind the covered pickups to compensate for this so that you'd essentially get the same tone whether you ordered covered or open poles. Hope this helps. Link to comment Share on other sites More sharing options...
Members TheRymanChu Posted February 19, 2011 Members Share Posted February 19, 2011 Covers attenuate a little high end, so open buckers are brighter which sounds clearer and more open or less muddy. Some say covered pups are mellower, smoother darker, warmer or less defined. Whether that is due to straying eddy current capacitance absorbed from the magnetic field (nickel-silver and brass reduce this) or from less output by simply being slightly farther from the strings is a matter of debate. The cover should shield a little noise, if you find that to be an issue. Uncovered pickups corrode faster, are easier to damage, and get an e string stuck in them. Personally, I like open pups in the bridge always, but I couldn't listen to an album and tell you whether the pups were covered or not. Link to comment Share on other sites More sharing options...
Members zeusecho Posted February 19, 2011 Author Members Share Posted February 19, 2011 Cool thanks for the feedback. I'll stick with the uncovered versions as they are less expensive and easier to find, at least than the gold. Link to comment Share on other sites More sharing options...
Members Johnny Two Tone Posted February 19, 2011 Members Share Posted February 19, 2011 Covers attenuate a little high end, so open buckers are brighter which sounds clearer and more open or less muddy. Some say covered pups are mellower, smoother darker, warmer or less defined. Whether that is due to straying eddy current capacitance absorbed from the magnetic field (nickel-silver and brass reduce this) or from less output by simply being slightly farther from the strings is a matter of debate. The cover should shield a little noise, if you find that to be an issue. Uncovered pickups corrode faster, are easier to damage, and get an e string stuck in them. Personally, I like open pups in the bridge always, but I couldn't listen to an album and tell you whether the pups were covered or not. Eddy current capacitance? Eddy currents are a loss-by-heat created by circulating electrons in the core of a magnetic winding. I don't understand how nickle as a housing to a magnet reduces high end from eddy current loss - especially in the form of capacitance. I mean what is the dielectric of that capacitor? Not saying what you said isn't true, just saying I would like this explained to me if true. Link to comment Share on other sites More sharing options...
Members TheRymanChu Posted February 19, 2011 Members Share Posted February 19, 2011 Eddy current capacitance? Eddy currents are a loss-by-heat created by circulating electrons in the core of a magnetic winding. I don't understand how nickle as a housing to a magnet reduces high end from eddy current loss - especially in the form of capacitance. I'm not an electrical engineer, so I had to do some reading. Here is what wikipedia says, "Eddy currents, like all electric currents, generate heat as well as electromagnetic forces. The electromagnetic forces can be used for levitation, creating movement, or to give a strong braking effect. Eddy currents can also have undesirable effects, for instance power loss in transformers. In this application, they are minimised with thin plates, by lamination of conductors or other details of conductor shape." From Bill Lawrence, "Perfectly wound coils are virtually free of eddy currents, and the effective resistance is about the same as the DC resistance. However, a piece of metal in the vicinity of a coil, like a pickup cover, as well as a minute short in a coil, will cause eddy currents. Nickel silver or stainless steel will cause lesser eddy currents than copper, brass, soft iron or aluminum. Eddy currents interfere with the induced current in a pickup and alter its performance." The electrical conductivity of the alloy used to make the pup cover will influence how easily eddy currents can develop. Nickel-silver is less conductive than brass: Copper (pure): 1.72 microhm-centimeter Brass: 6.16 microhm-centimeter Stainless Steel: 72.0 microhm-centimeter Nickel Silver: 130 microhm-centimeter The larger the microhm-centimeter value, the smaller the eddy currents, in inverse proportion to the value. The thickness of the metal sheet also matters, thicker sheets yielding larger eddy currents, in direct proportion to the thickness, covers are typically between 0.022" and 0.025". A thinner brass cover is capable of less capacitance than a thicker nickel-silver cover. Link to comment Share on other sites More sharing options...
Members Johnny Two Tone Posted February 20, 2011 Members Share Posted February 20, 2011 I'm not an electrical engineer, so I had to do some reading. Here is what wikipedia says, "Eddy currents, like all electric currents, generate heat as well as electromagnetic forces. The electromagnetic forces can be used for levitation, creating movement, or to give a strong braking effect. Eddy currents can also have undesirable effects, for instance power loss in transformers. In this application, they are minimised with thin plates, by lamination of conductors or other details of conductor shape." From Bill Lawrence, "Perfectly wound coils are virtually free of eddy currents, and the effective resistance is about the same as the DC resistance. However, a piece of metal in the vicinity of a coil, like a pickup cover, as well as a minute short in a coil, will cause eddy currents. Nickel silver or stainless steel will cause lesser eddy currents than copper, brass, soft iron or aluminum. Eddy currents interfere with the induced current in a pickup and alter its performance."The electrical conductivity of the alloy used to make the pup cover will influence how easily eddy currents can develop. Nickel-silver is less conductive than brass:Copper (pure): 1.72 microhm-centimeter Brass: 6.16 microhm-centimeter Stainless Steel: 72.0 microhm-centimeter Nickel Silver: 130 microhm-centimeter The larger the microhm-centimeter value, the smaller the eddy currents, in inverse proportion to the value. The thickness of the metal sheet also matters, thicker sheets yielding larger eddy currents, in direct proportion to the thickness, covers are typically between 0.022" and 0.025". A thinner brass cover is capable of less capacitance than a thicker nickel-silver cover. Interesting information but I'm not sure I believe a single bit of it (or maybe more accurately put understand any of it). Magnetism is a result of electrons moving through a conductor. As electrons (current) moves along the conductor a certain amount of energy is changed into magnetism. This magnetism sets itself up in the form of flux lines. With AC, current moves back and forth slowing down and speeding up as it changes direction which makes the flux expand and contract. With DC the current gets up to a value and stays there, therefore the flux stays stable. Now, since the pickup is a permanent magnet (ie. it's a magnetic material and does not need current flow to be magnetic) it has an always stable setup of flux surrounding it. The strings of the guitar pass through that magnetism. The strings "cutting" the flux causes a counter electromotive force into the conductor (the winding). This current passes from the pickup to the amp, which transforms the current blah blah blah... sound output. Eddy currents is just a term for a property of an action of current flow. Usually, current circulates in the core that the winding are wrapped around. A housing to the windings is not electrically connected to the core or windings and therefore should not act as anything more than a redirector of the flux (a path for the flux can be assisted with a metal). What I need to know is how does circulating currents take place in the metallic shell around a magnet and how does that cause the high end producing portion of the actual magnet/winding device become less effective? Link to comment Share on other sites More sharing options...
Members Neilrocks25 Posted February 20, 2011 Members Share Posted February 20, 2011 Cool thanks for the feedback. I'll stick with the uncovered versions as they are less expensive and easier to find, at least than the gold. Get zebra Pick ups as they look cool Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted February 20, 2011 Members Share Posted February 20, 2011 I've removed covers before and the tonal difference is negligible, I guess if you put through a frequency analyzer, you'd see some difference but through a loud guitar amp, you won't hear any difference. Go with what looks better for you, it's no big deal either way. Link to comment Share on other sites More sharing options...
Members Johnny Two Tone Posted February 20, 2011 Members Share Posted February 20, 2011 From Bill Lawrence, "Perfectly wound coils are virtually free of eddy currents, and the effective resistance is about the same as the DC resistance. However, a piece of metal in the vicinity of a coil, like a pickup cover, as well as a minute short in a coil, will cause eddy currents. Nickel silver or stainless steel will cause lesser eddy currents than copper, brass, soft iron or aluminum. Eddy currents interfere with the induced current in a pickup and alter its performance." Oh, this bolded part of that quote also makes very little sense. The core contains the potential for eddy currents; changing the winding isn't the primary affecter for that potential (changing the physical build of the core would be). "Effective" resistance is the resistance. The "other" type of resistance is called reactance. Capacitance and inductance is reactance. Adding reactance and resistance gives you the impedance. So, saying the effective resistance is the same is like saying an orange is an orange. What I need to know is where is the reactance; what is storing the energy? Eddy currents LOSE energy though heat. If the reactance was super low than it would be legit to say that the Impedance would be "about the same as the DC resistance" but that still doesn't tell me how that affects the high end of the pickup. Link to comment Share on other sites More sharing options...
Members Belva Posted February 20, 2011 Members Share Posted February 20, 2011 Before I opened this thread I knew what I'd read. And I was right. This is a debate similar to the lacquer vs poly and set vs bolt neck debates. Guitarbilly74 hit da nail on da head. You ain't gonna notice a damn thing. If you make the claim that you can, well, you're so full of {censored} you're gonna choke on it. And don't even get me started on the type of tone cap in a guitar debate. That's another Voodoo horse{censored} lie. Link to comment Share on other sites More sharing options...
Members Johnny Two Tone Posted February 20, 2011 Members Share Posted February 20, 2011 Before I opened this thread I knew what I'd read. And I was right. This is a debate similar to the lacquer vs poly and set vs bolt neck debates. Guitarbilly74 hit da nail on da head. You ain't gonna notice a damn thing. If you make the claim that you can, well, you're so full of {censored} you're gonna choke on it.And don't even get me started on the type of tone cap in a guitar debate. That's another Voodoo horse{censored} lie. Well, I'm not sure anyone has actually flat out said that they KNEW it did something. Moreso just repeating what they've heard. Usually, if someone can't answer the questionable physics of it then it doesn't exist. Link to comment Share on other sites More sharing options...
Members Belva Posted February 20, 2011 Members Share Posted February 20, 2011 Well, I'm not sure anyone has actually flat out said that they KNEW it did something. Moreso just repeating what they've heard. Usually, if someone can't answer the questionable physics of it then it doesn't exist. Well played, sir! So many fractured fairy tales exist in the world of amplified guitar it boggles the mind.The only thing I know for sure is that a good rock & roll drummer has knuckles that drag on the ground. Link to comment Share on other sites More sharing options...
Members Johnny Two Tone Posted February 20, 2011 Members Share Posted February 20, 2011 Well played, sir! So many fractured fairy tales exist in the world of amplified guitar it boggles the mind. The only thing I know for sure is that a good rock & roll drummer has knuckles that drag on the ground. Haha, who you calling ugly! The biggest myth I got over was the notion of "tone wood", when I was building my guitar (which is almost finished!!!AHAH!!!AHAHAHA!!!!). It's like, how can there be "better" sound? You either like it or you don't. Link to comment Share on other sites More sharing options...
Members TheRymanChu Posted February 20, 2011 Members Share Posted February 20, 2011 I never said there was an audible difference, and I never said I was qualified to answer this question. Since I have read the same explanation from Seymour Duncan, Kinman and Bill Lawrence, I am inclined to believe it. I was trying to give a simple answer, but since you wanted a scientific explanation, I will try anyway. This is from the Physics Department at University of Illinois at Urbana-Champaign: http://online.physics.uiuc.edu/courses/phys498pom/lab_handouts/electric_guitar_pickup_measurements.pdf. The (lumped) inductance, L(f) and its associated dissipation, DL(f) of an electric guitar pickup are measured using a Hewlett-Packard 4262A LCR meter at three different frequencies: f = 120 Hz, 1 KHz and 10 KHz. The HP LCR meter analyzes inductance L(f) and dissipation DL(f) as a Link to comment Share on other sites More sharing options...
Members zeusecho Posted February 20, 2011 Author Members Share Posted February 20, 2011 Sorry I didn't mean to start such a technical debate. I was just curious if there was a "noticeable" difference in the tone. It sounds like there is not, so go with whatever looks the best. Thanks for the feedback everyone! Link to comment Share on other sites More sharing options...
Members zeusecho Posted February 20, 2011 Author Members Share Posted February 20, 2011 Get zebra Pick ups as they look cool Yeah I like the zebras also but not in a black LCP. Link to comment Share on other sites More sharing options...
Members FBird Nation Posted February 20, 2011 Members Share Posted February 20, 2011 It used to be a 'heat' difference, back in the day; Covers were removed to give the pickup a hotter signal. But that was a long time ago; covered pups are probably wound to compensate for this now... Link to comment Share on other sites More sharing options...
Members Johnny Two Tone Posted February 20, 2011 Members Share Posted February 20, 2011 /DLp(f). In reality, an electric guitar pickup is considerably more complicated than the simple, very crude model of a pickup consisting of a lumped series L-R in parallel with a lumped C, because the actual L, R and C are distributed over the many thousands of turns of the pickup coil. Furthermore, the pickup inductance, L is not a constant, independent of frequency due to frequency-dependence of the magnetization, M (magnetic dipole moment per unit volume) of the permanent magnet(s) used in the pickup, how fully the magnets are charged (i.e. where the permanent magnets reside on the B-H hysteresis curve) as well as the frequency-dependent properties of the magnetically permeable material(s) used in the construction of the electric guitar pickup Link to comment Share on other sites More sharing options...
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