String theory is the scientist theory that everything at the very base level of matter such as the various types of quarks is created or comprised of the different modes of vibration of a 2 dimensional “string”
Great video, interesting explanation, Marc. Focussing on the field lines is rather difficult, even though I agree that a retrieving string enlarges the magnetic field in size (as you have shown). What is much more significant, I think, is the change of field strength with the moving string.
Thank you! You are correct but at the same time a more spread out field is weaker per unit of space. So I'd say it boils down to the same thing, wouldn't you? Edit: I had a quick look at your channel and you obviously know your stuff! Best regards,
Thanks for letting me know! I am an amateur in physics myself, I just keep reading and thinking and every now and then I think I see some light ;-) Let me know what your students think if you have time?
@@skyraiderjet Probably if you talk about traditional jazz. If you take jazz as improvising over a given theme it could be anything. And there's the odd guy who makes a traditional jazz guitar like the Gibson Byrdland scream like there is no tomorrow.
The strings also become magnetized by the pole pieces which bring the magnet's field up to each individual string. The pole pieces are adjustable to bring the pole piece magnetizm closer to the string to magnetize it.The string being ferro-magnetic will form a weak magnetic fileld (N=S) in the immediate vicinity of the string. I have proven this by taking a bass string (E) from a guitar and then pourin some iron dust around it and observing the weak magnetic field shown by the iron dust and a compass.
Thank you so much for this informative series of videos! It's like a veil of ignorance is being lifted from my mind with every video of yours I watch. You're a magnificient teacher. 🙏
Hi Marc, I was wondering if you could help me out a bit - I am doing a university dissertation on guitar pickups. I have built 4 pickups for comparison: all humbuckers with 42AWG wire and the same number of turns (5350 on each 50mm bobbin), but with a different magnet in each pickup - Alnico 5, Alnico 4, Alnico 2 and Ceramic 8. I have audio clips of each pickup tested using the same plucking velocity and same guitar etc. Basically the only thing that is different is the type of magnet, in order for a fair test. I was wondering if you could tell me what differences I should see in each magnet? ie. characteristics in tone and output levels? I'm finding it hard to get the information that says this. Any input of yours would be greatly appreciated as I found your video inspiring and informative. Cheers, Elliot
The stronger magnets should give a larger magnetic flux passing through the coils and thus a higher output voltage. As far as tone is concerned I'm not certain; experience learns that ceramic magnets sound more trebly. But I have no good means to measure magnetic strength so I'm guessing if I say it is because they are stronger. I'm curious to hear your test clips; also, can you put the signals through a scope to visually compare them?
Hi Elliot, I'm reading this thread a year later, but would be very interested in the results of your test. Did you finish your investigation and can you share the results?
This explanation is the closest I have heard to date and it's the closest to my electronics training and automotive training. Simply a conductor moving through a magnetic field induces a voltage change. In automotive you collapse the magnetic field around the coil of fine wire. Guitar pickups move a ferris material through the magnetic field to induce a current in the windings. Good job.
Hi Marc , I appreciate your video. One question, it seems you didn't consider lenz law right? If we consider lenz law, the coil current will be in opposite direction in the video. Of course, it doesn't affect your explanation. The hum will be cancelled, the guitar signal will be doubled.
nice video man!!, also you can explain the induced voltage in a coil whith the formula $e_ind= -N dF/dt$ were e_ind is the voltage induced in the terminals of the coil, N is the numbers of turns of the coil and dF/dt is the rate of change of the magnetic flux perpendicular to the plain of the coil, the minus sing is bc the induced potential oposes to the change in the flux.
Thank you for taking the time to put this together. I work in a well known custom shop making guitars. I make the pick-ups, and I’m currently in the process of writing a manual for future staff that get trained in this area. I do have a question, can you recommend any books out there on the subject?
Thank you! It's hard to name a specific title. Before I made these videos I had been brushing up on classical mechanics, with a bit of a focus on electrodynamics.
You are legend, great videos. absolutely inductance is by far more important then resistance regarding characteristics - meaning it tell us more so We can ''imagine'' how it will behave. Pickup is nothing more nor less then a mic made in such way, it works in same principle as mic, speakers and headphones etc. how those strings will vibrate will depend from material of bridge, and above all of guitar aka body+neck. Of course material with which we pluck the strings nails, flash or pick. So pickup literally mic it up aka collect the sound, it can be used as mic not as great mic but would work OK 100%.. As electronic engineer and a person who make pickups etc i found it that famous pickup sellers/winders sell myths to people. It is sad a absurd that people who know things or understand like you do have never runed for $ which is OK, while others who sell dreams and lies will sell a simple pickup for 500$ wouldn't any sort of moral brakes or norms. Complete industry in based on that even in guitar magazines they feed the myths. Anyhow thx for this videos, wish you all the best.
Thank you!!!! This was a lot of work for you and I appreciate it very much. Thanks for getting into the physics of what is really going on. Well done!!
Yo this was a great video, im a guitar player and im doing a project on how guitars work for my physics class. This video was really helpful for that and also really interesting at the same time so thank you.
I took a physics electromagnetics class back in 1984 and never understood the stuff because it was so theoretical. It would have been nice if the teacher had knowledge of some practical uses for the stuff , but I only see the practical uses thanks to youtube. I don't understand how a tool and die maker knew you could amplify the noise using that setup back in the 1930s. crazy!
My question is, what if you had a super strong magnet? Like the ones used in computers? How would this effect sound or playability, if at all? Ive been curious about this for a while
The stronger the magnet, the higher the output of a pickup but if the magnets are too strong they start interfering with the vibration of the strings, dampening them or even causing out of tune overtones. You can experience this when you put a pickup too close to the strings. That being said I think in some modern pickups neodymium magnets are used but there are always limits to how strong the magnetic field can be close to the strings.
@@aaronstonebeat yes! That was their name. I couldn't remember it off the top of my head. Well, dang. I thought I had a genius idea for new pickups 😂 thanks for the explanation man!
So if I'm getting this correct, the vibration of the string across the magnets create an alternating current, which is the signal that gets amplified and listened to?
You could provide a great voice-over for "Count Dracula". :-) Regarding what's happening with the string, magnet, & copper coil, here's how I would describe it: 1. The energy used to put the metal string into motion is the beginning. 2. As the string moves & vibrates, it, being a ferrous metal string, conducts & concentrates the magnetic field within itself, & it therefore consequently disrupts the normal magnetic field that encompasses the copper coil. 3. That change in the normal magnetic field proportionally affects the free electrons within the copper to cause a force (Voltage) & a movement of charged particles (electrons) to move & ripple through (current (A) flow) the copper. 4. That V & A is what is conducted into an amplifier before it is conducted to a speaker for our listening delights (hopefully). hth!
Thank you so much for sharing this! I'm a physics professor and novice guitar player and I've been looking for a more in depth explaination of the physics behind guitar pickups. This has been extremely helpful and I can't wait to share the information with my students!
You don't have to resort to quantum mechanics give a satisfactory description of the phenomenon, and I'll suppose you said string theory as a joke about guitar strings, cause that would be like trying to use the concept of brownian motion to explain hurricanes. All you need is Maxwell's equations to describe the behavior of the magnetic fields involved.
Can you make a video theory lesson about guitar pickup magnetic heat treated process, magnetic impulse time response, magnetic Coercivity. I would like to know the theory behind guitar pickup magnetic heat treated process and what it does and also how to change the magnetics impulse time response which is the time interval of the guitar string to the pickups output voltage/current and the magnetic coercivity is the picking sensitivity. The LOWER the magnetic coercitivty the easier the pole piece is magnetized, but why?
I have a legit question: the electricity out of the pickup is alternate. In pickups specs, the label + and - the start and the finish of the winding. With the north to the strings coils, start is + and finish is - , and with the south to the strings coils, the start is - and the finish is + . Can you explain that, please? I have further questions, but if we can begin with that it would be great. Thank you, I loved the video!
When both pickups are switched on at the same time they are humbucking because of this construction; the coils are out of phase because plus and minus are reversed (canceling external interference) but the signals are in phase because the magnets are also reversed.
@@aaronstonebeat Thanks for replying! I know about humbuckers, my question is not about them. In my question im just talking about a single coil pickup that you can put a string in one side or the other, or just use a pickup with north up, and then change for another with south up. Can you read the question again with this in mind, please?
@@aaronstonebeat I also know that the winding is the same, you just use one side or the other of the magnet and then the resulting winding direction is clockwise or counterclockwise. But if you have the string in the north side the label of start is + and the finish is - , but if you have the string in the south side, the start is - and the finish is + , and there is where my question is leaning onto.
@@diegopedroroldanmerino4208 Two single coil pickups can also be humbucking (they often are), that is the only reason for the electrical and magnetic reversal. If only one pickup is on it doesn't matter. If two pickups are on and plus and minus are connected the same but the magnets point different ways they will be out of phase; and if the magnets are oriented the same but plus and minus are reversed they will also be out of phase.
@@aaronstonebeat FORGET ABOUT HUMBUCKERS! it is just one pickup in this example, my question is not about two pickups conected together!!!! If I put ONE single coil north up clockwise winding, the start is labeled as + and finish - in the specs. Imagine we REPLACE it, and put just one pickup in this imaginary guitar, wich is south up, counterclockwise winding, the start will be labeled as - and the finish +, and that is what I don't know why it is, do you? Why the start will change to be labeled from + to - depending on where the string is vibrating ("where" meaning the north pole or the south)?
Hi there, really love your video series! I do have a question though. When you say 'More ferromagnetic core material = higher inductance', do you mean that using pole pieces with a .195" diameter instead of .187" (assuming the same height) would lead to higher inductance? Thank you!
I am a luthier who is beginning to build my own pickups from scratch. Like most enthusiasts Id like to experiment with differ winding configurations, magnetic strengths, number of windings, etc. Do you have any advice for me, any ideas you would like to see tried?
Mark Von Sting... 9 YEARS AGO.. I very seriously doubt that you still have this account. But nevertheless, since it HAS been so long; I'm now quite interested on how your journey as a luthier, moving towards custom pick up builds has worked out for you? That is if you are still there and care to share.
MARC VAN, when you put a Dummy Coil in series it cancels out the HUM noises from a single coil pickup. Why does a Dummy Coil cancel out the HUM noises when there is no magnets in the dummy coil have no magnets and the dummy coil is NOT reversed wound. So how does the Dummy Coil reverse the polarity phase of the HUM noise?
It only works if the dummy coil IS connected out phase with the single coil pickup. Any piece of metal, so also a wire or a coil, will be an antenna that picks up electromagnetic waves (hum); only in combination with a magnet will a coil transduce a signal from a vibrating ferromagnetic string.
As a string moves back and forth over its pole screw it seems the response in the coil would be the same as it moves off center in either direction. Would this not produce a 2nd harmonic? There must be a gradient in the magnetic field to get the fundamental response.
That is probably a great question and on one hand I'm not sure how to answer it while on the other I'm sure you're right. But then the whole series of harmonics is present in the vibrating string to begin with so it will also be in the vibrating magnetic field.
Isnt it so that the magnet is only there to magnetize the string. When magnetized the vibration of the string causes a vibrating magnetic field being picked up by the coil resulting in an osilating voltage. It is not the string infuencing the magnetic field of the core as explained here. When the string is magnetized you actually dont need the magnet anymore so a coil with only ferromagnetic core would work equally (until the string losses its magnetic strength).
I think that is partly true. The strings do get magnetized and cause inductance in the coil when vibrating but all on their own the part of the coil away from the strings would be a lot less affected than the part close to the strings.
Not so easy to really determine, I think. At rest there is a flux depending on the magnet strength but in action it is the changing magnetic flux that counts. This depends on a few thinks that draw quite a complicated picture if you try to describe reality: the frequency and amplitude of vibration of the string(s), the thickness/mass of the string and is ferromagnetic properties and the surface of the coil windings. I'd try to go for one frequency and amplitude from a signal generator to begin.
The strength of the magnetic field changes perpendicular to the wire of the coil, either inward or outward and so and electrric field is induced in the wire, either one way or the other, perpendicular to the direction of change of the magnetic field.
They have to be conductive, so a grosso modo, yes. A moving electric charge causes a magnetic field (this is the aim of it). You're looking for a variable magnetic field in order to get current in the wire.
True, that should work. Time to buy a set of magnetic strings and test it ;-) Or pass a current through the strings. That will create a magnetic field.
This is super fascinating and helpful, but I have one question that I can't seem to find an answer to anywhere. Why does one of the poles of the magnet have to face the string? I know that the poles of the magnets tend to have the strongest pull, but would turning a magnet sideways so that the string is vibrating through the center of the magnet still yield a useable output?
Notice how all magnetic field lines cross the strings in the same direction; if the magnet were on its side one half of the pickup would be out of phase with the other half. In humbucking pickups you find bar magnets on their side often but they are underneath the pickup; pole pieces extend the magnetic poles towards the strings and each set of pole pieces has its own coil. Also in P90 pickups there are two bar magnets on their side underneath the pickup; in these pickups the same pole of the bar magnets is held in place against the pole pieces which extend that pole towards the strings.
@@aaronstonebeat Oh, that makes a lot more sense! I've been trying to see if there is a way to modify an electromagnetic pickup to work on a bowed instrument like a violin or a cello. Guitar pickups don't work well on bowed strings because guitar strings seem to pick up movement towards and away from the magnetic pole and a string that is bowed vibrates side to side, not up and down. I was talking to someone today about it and they showed me a picture of an electromagnetic pickup for a violin that I had never seen before, but it only had three pole pieces and they all went between the strings rather than underneath them to compensate for the difference in motion. Do you think that set-up would be able to pick up a decent signal from a bowed string?
@@aaronkath6083 You are correct about the direction of motion of the strings relative to the pickup. From there it would seem to make sense to have the pole pieces between the strings but I am totally unfamiliar with pickups for violins. I can imagine the pole pieces rising up between the strings while the coil would still be in the traditional place; so basically a guitar pickup with extended pole pieces. Do you have a brand name or something that would help finding pictures of such a device? You've made me curious.
@Pana6Ion No, wider turns enclose a larger surface; more magnetic flux passes through a larger surface. So given the same amount of turns and the same magnetic field strength a wider coil will have higher inductance.
@custardpiekashmir De resonantie-eigenschappen van de gitaar beïnvloeden de manier waarop de snaren trillen. Zo hoor je bijvoorbeeld heel duidelijk verschil in het versterkte geluid tussen een holle en een massieve gitaar.
Isn't string vibration more or less normal/perpendicular to the magnetic field as you have it depicted in 2:55? If you pluck a string, it vibrates side to side, perpendicular to the slug. But it would still move within the magnetic field of the slug I think.
Actually the strings vibrate in all directions but it is mainly the movement to and from the magnets/slugs that causes the magnetic field to vibrate with the strings and induce voltages in the coil.
@@aaronstonebeat Yeah I assume they would, but vibration in the horizontal plane would seem to be the most prominent frequencies, no? Also, I wonder if you would get a stronger/more sensitive signal if the slug were played sideways next to a string.
@@EatScrabbleGoo That might be a nice experiment; you could try to mount a pickup next to a string and find out if there is a difference. But it wouldn't be very practical, would it?
@custardpiekashmir Gebruikte materialen hebben ook een invloed op het geluid maar ik kan me zomaar voorstellen dat een glazen elektrische gitaar prima klinkt. Er zijn ook mensen die gitaren van aluminium of staal maken; er circuleert ergens een filmpje van een gitaar waarvan de body van een blok beton is gemaakt. Maar ook gitaren van naaldhout en hardboard (bv Danelectro) hebben een karakteristiek en eigen geluid dat sommigen zeer waarderen.
Yes I like ! Dont know if i understand this, so i need 2 ask u a q: If the string was made up of, say 4k turn of isolated wire, starting & ending on the brideg u could throw away the pickup coil, and instead use the string itself as the pickup, if it was connected to the amp as the 'coil' circuit..? I mean, any (fe-based) conductor will be induced with a current if moving trough a magnetic field? Ok, thanks for this xellent video!
according to Lenz the blue arrow should be the initial direction of speed of electrons, rectangular to the magnetic field lines, that causes the lorentzkraft. you describe it as direction of movement of the field lines. maybe it'd be better to imagine it as the increased/decreased pull of the magnet on the copper wire, wich in theory causes micro contraction/relaxation of the copper wire around the magnet. this way you could explain the direction of induced current with the usual three dimensions (magnetic induction, lorentzkraft, and speed (and direction) of electrons).
But copper is not really magnetic, hardly anyway. Electrons have a charge and respond to changes in the magnetic field. Pickup wire can be potted or cast into epoxy resin and have virtually no freedom of movement at all and still produce a very good guitar signal. So why?
Honestly because I do not understand how you can simply exchange these two dimensions: Direction of change of the magnetic induction B speed and direction of travel of electrons (as in the general formula for the Lorentzkraft). Is there an explanation for why they are equivalent here?
Hey there, I have this school project! I was wondering if its possible to find magnetic flux in my electric guitar knowing its EMF(voltage) using Fraday's law...How could I do that. If you can please tell me, i would appreciate it! Hope you understand my question which I think you do!
Mate! great video. i remembered studing this in the Phisics lessons 15 years ago...so, dont remember that much anymroe :P Look, reagarding the copper wire around the magnet: we need several turns in order to get higher induction? The differnece in potential is measured from one point to the other point of the wire?? thanks
Hallo Marc, kun je ook het geheim uitleggen van het allereerste commercieel verkochte horseshoe element van rickenbacher, uitgevonden door George Beauchamp, en gepatenteerd in 1937. Ik probeer al enkele jaren om zo een element te maken, voor mijn lapsteel gitaar, met wisselend succes. Groetjes Jean uit Belgie.
Beste Jean, Het principe is niet anders dan dat van 'normale' pickups; een spoel in een magneetveld. Alleen zijn het hier twee U-vormige magneten, met gelijke polen boven en onder de spoel (beide noord boven of beide zuid boven). Het geheim zit 'm ongetwijfeld in de dimensies, het gebruikte wikkeldraad, het aantal windingen, de sterkte van de magneten, het materiaal van de poolschroeven. Ik zal je vast niets nieuws vertellen en de juiste maten van al die ingrediënten weet ik niet. Is daar niets over te vinden in het oorspronkelijke patent? Wel tof om te proberen zoiets te maken!
@@aaronstonebeat Bedankt Marc, ja ik ken het aantal windingen (+/- 5000) van .38 AWG draad, dan kom je uit op ongeveer 1.8 K Ohm DC weerstand. Ik heb ooit een Rickenbacher gekocht en daar heb ik alle maten van gebruikt. Het enige wat ik niet weet is van welk materiaal de 'poolpieces' gemaakt zijn, en het exacte soort staal. Volgens sommige amerikaanse sites is het O1 Toolsteel, wat in Europa overeen komt met 1.2510 gereedschaps staal. Verder heb ik nog een stuk of 5 andere soorten gereedschapsstaal geprobeerd met allemaal verschillende percentages koolstof, silicium, mangaan, chroom, vanadium enzovoort. Maar blijkbaar is het percentage Wolfram of Tungsten belangrijk, en laat dat nu niet, of weinig aanwezig zijn in het meeste soorten gereedschaps staal. Het is waarschijnlijk daarom dat ik deze staalsoorten onvoldoende gemagnetiseerd krijg. Ik ben wel al heel kort bij het geluid dat ik zoek, en dat kun je horen in de link hieronder. Dit is een oude jaren '30 rickenbacher. ua-cam.com/video/8ArwAqM88Kw/v-deo.html Groetjes Jean
@@germona Ik heb ooit wat geëxperimenteerd met het maken van pickups; gewoon om te kijken of het überhaupt kon. Als 'pole pieces' gebruikte ik boutjes van een bouwmarkt; mijn test voor bruikbaarheid was of ze voldoende aan een magneet bleven plakken 😁 Sommige staalsoorten zijn maar zwak magnetisch; een hoop 'goedkoop' standaardspul is ruim voldoende ferromagnetisch. Voor een element is 1,8 kOhm niet buitensporig veel. Maar ik weet uit ervaring dat het heel mooi en helder kan klinken.
Actually the magnetic field changes when the string moves because the magnetic field lines prefer travelling through ferromagnetic materials like the string. When the string is nearby it basically sucks the lines in distorting the magnetic field. The closer it is to the magnetic lines the more it can suck them in, resulting in a changing magnetic field, and that's what induces a voltage in the coil. You can test this by very very very carefully sliding a ferromagnetic material (mild steel) on top of the pick up, which will suck the magnetic lines in and there wont be anything left for the string to distort. But be very slow to avoid generating a large voltage as you distort the magnetic field.
You are a cool guy to help us musicians with the scientific underpinnings of pickups. I liked how at the beginning You made the point that much of this was understood a century ago, and other parts might require Quantum Mechanics or even string theory yet the deeper one dwells, more questions arise and so on.
The guitar string isn't pulled away from the pickup, it moves perpendicular to the pickup. Also if I remember my right hand rule correctly (from 30 years ago) the current will always flow in the same direction unless the poles of the magnet are changing. So the guitar string vibrating only causes the strength of the current to fluctuate not the direction.
Nice explanation. If I understood the Lorentz force correctly I would assume there is also an electric current in the string itself (because it's a conductor moving in a magnetic field). Is that correct? And if yes, why it is not used to pickup the tone.
You are right but amplifiers (tubes or transistors) respond to change in voltage, not current. Also the induced voltage in a string is very small because it passes just once through the magnetic field whereas the wire of the coil passes thousands of times through the magnetic field.
Thanks Marc, I have a personal bass guitar project, where I would like to install the pickups along the strings instead of across them, what do you think about?
That could be made to work but it might have disadvantages; you'd need at least two pickups where normally one would be enough and the pickups would have to be very similar in specifications. I think I would build a setup where I could mount the pickups above the strings in various orientations and configurations to test the differences in sound and decide whether it is worth the trouble.
Thanks! You are right on both points: the more turns there are the higher the inductance and the potential difference that can be induced between the ends of the wire.
wood definitely has nothing to do with the guitar tone, a while ago +willseasyguitar did an experiment with a frequency generator proving that, you should check that out. The pickup, nut material (bone,brass etc...), the bridge material and tuners. Basically anything the string is in touch with affects the tone. A brass nut will give you a brighter tone for example.
It has been demonstrated with a magnetless pickup that it is in fact the magnetic field around the string moving through the coil that induces the current in the coil. Search for zexcoil, there is a fuller explanation.
I have searched for 'Zexcoil' and found they use individual coils and magnets per string. Innovative! If there were no magnets where would the magnetic field around the strings come from?
Also. Search this article for the word nuts for the salient paragraph. www.seymourduncan.com/blog/the-tone-garage/seymour-w-duncans-interview-with-seth-lover
@@tochriss I've read the article and I find it inconclusive about how the strings are magnetized; still, some form of change in magnetic flux makes a coil induce a change in voltage. So what's different from that than what I talk about in my video?
that would be an insulated wire though I presume... wire alone isn't insulated and wouldn't work, right? It would immediately short out and there'd be no coil i.e. inductance effect.
You're right. The wire in the bobine is isulated. If foy any reason in the middle of the coild the isolation brakes, the RC will reduces proportionaly and the output would be very weak or nule.
I am experimenting on a 5.1 stereo surround chorus effect using an acoustic guitar and piezo and other mics to create a 6 output signal. My first setup was to use 4 mics inside the gtr 2 upfront and 2 in the back to get a front L/R stereo and back L/R stereo with the under the bridge pickup used as the center and sub.I also want to try a second setup using individual coils for each string. The low E would be the sub A would be back Right D would be back Left G- front Left B front-Right little E-center. My ? is what type of coil should I use for a one string pickup using 6 separate magnetic fields for each string? Is there any Electromagnetic coils that would be good for this or would this have to be hand made? Any helpful hints that I could try? I also am looking ahead to phase and impedance also delay and chorus effects then preamped and sent out as 3 1/4" TRS stereo L/R low impedance signals to the mixing board and routed to there assigned speakers? Any Thoughts on this would be very appreciated!
I know individual pickups for each string are used to trigger guitar synthesizers, so they do exist. Maybe that is something to look around for? It wouldn't be that hard to make such pickups by hand though. A thing I once tried: take a head from a cassette player, hold it close to a string and have a magnet nearby and you get a signal! Those are small coils that produce only a low voltage but if you're using preamps and it's for acoustic sounds that should be no problem. Those are the first thoughts that come into my mind.
Marc van Oppen Thanks Marc Im gonna try the cassette head path. Could you give more info on how the setup would be? Im guessing a head for each string?And were is the magnet? Under the cassette head i'm guessing? I have to ask? You thought 6 mics in a acoustic guitar is gonna be Noisy as Hell didn't you Marc? But you think 6 pickups on each string would produce better results? It would be easier to do? Would you place each string like I planned in the speaker arrangement or would another arrangement be better? And last ? is there gonna be any problems with phasing or polarity in creating a stereo surround sound effect? Sorry about all the ?'s but your pretty smart about this topic and you seem to be a experimentalist like myself ?LOL! Thanks Marc that was alot of help! I'll let you know how things turn out!
Fourstringplayer Bassman First of all: it is a thing I tried only once because I expected it to work; but it was just one head and one string. Indeed I held the magnet underneath the cassette head. Microphones will give a more natural sound but they also will pick up all the noise from handling the guitar. 6 Pickups will allow you to hear each string virtually individually and with a lot less noise. How to place the strings in the speaker arrangement? I wouldn't know, I'd have to try. But you have a plan; so try that and see if it needs adjusting. Sounds like fun! Good luck!
i couldnt help laugh at the "hither and thitharrrrr"
Yes funny as hell!
I’m now going to add this to my daily vernacular. Surely the only people legally allowed to say this wear a monocle and powdered wig…
String theory jajajaj right!
I was thinking the same!!!! Lolll
I laughed
Wait this whole thing is string theory though...
String theory is the scientist theory that everything at the very base level of matter such as the various types of quarks is created or comprised of the different modes of vibration of a 2 dimensional “string”
😂
Try to make a 7 year old watch this lol.
I wouldn't force anybody ;-)
What were you thinking?
Great video, interesting explanation, Marc. Focussing on the field lines is rather difficult, even though I agree that a retrieving string enlarges the magnetic field in size (as you have shown). What is much more significant, I think, is the change of field strength with the moving string.
Thank you! You are correct but at the same time a more spread out field is weaker per unit of space.
So I'd say it boils down to the same thing, wouldn't you?
Edit: I had a quick look at your channel and you obviously know your stuff! Best regards,
Thank you, Marc. Your musical performance is way much better than mine. :-)
Thank you for that explanation Christopher walken
Much obliged.
His voice makes me so happy....
scotty22456 i thought it was Christopher Walken at first :)
Thanks for letting me know! I am an amateur in physics myself, I just keep reading and thinking and every now and then I think I see some light ;-)
Let me know what your students think if you have time?
So do jazz pickups have a lower impedance?
@@skyraiderjet Probably if you talk about traditional jazz. If you take jazz as improvising over a given theme it could be anything.
And there's the odd guy who makes a traditional jazz guitar like the Gibson Byrdland scream like there is no tomorrow.
The strings also become magnetized by the pole pieces which bring the magnet's field
up to each individual string. The pole pieces are adjustable to bring the pole piece magnetizm closer to the string to magnetize it.The string being ferro-magnetic will
form a weak magnetic fileld (N=S) in the immediate vicinity of the string.
I have proven this by taking a bass string (E) from a guitar and then pourin some iron
dust around it and observing the weak magnetic field shown by the iron dust and
a compass.
Love it how the older YT videos answer my questions. Thanks for being informative!
this is one of my favorite videos on youtube now. Thanks from norway!
Thank you so much for this informative series of videos! It's like a veil of ignorance is being lifted from my mind with every video of yours I watch. You're a magnificient teacher. 🙏
Hi Marc,
I was wondering if you could help me out a bit - I am doing a university dissertation on guitar pickups. I have built 4 pickups for comparison: all humbuckers with 42AWG wire and the same number of turns (5350 on each 50mm bobbin), but with a different magnet in each pickup - Alnico 5, Alnico 4, Alnico 2 and Ceramic 8. I have audio clips of each pickup tested using the same plucking velocity and same guitar etc. Basically the only thing that is different is the type of magnet, in order for a fair test.
I was wondering if you could tell me what differences I should see in each magnet? ie. characteristics in tone and output levels? I'm finding it hard to get the information that says this. Any input of yours would be greatly appreciated as I found your video inspiring and informative.
Cheers,
Elliot
The stronger magnets should give a larger magnetic flux passing through the coils and thus a higher output voltage. As far as tone is concerned I'm not certain; experience learns that ceramic magnets sound more trebly. But I have no good means to measure magnetic strength so I'm guessing if I say it is because they are stronger.
I'm curious to hear your test clips; also, can you put the signals through a scope to visually compare them?
Hi Elliot, I'm reading this thread a year later, but would be very interested in the results of your test. Did you finish your investigation and can you share the results?
I'd like to see the results too
Hi Elliot. I think your university disertation went bad because there was not conclusions at all from you, which we kept waiting.
Read Faraday’ s law. How magnetic fields and electricity coexist. - electromagnetism
This explanation is the closest I have heard to date and it's the closest to my electronics training and automotive training. Simply a conductor moving through a magnetic field induces a voltage change. In automotive you collapse the magnetic field around the coil of fine wire. Guitar pickups move a ferris material through the magnetic field to induce a current in the windings. Good job.
Thank you, sir!
Hi Marc , I appreciate your video. One question, it seems you didn't consider lenz law right? If we consider lenz law, the coil current will be in opposite direction in the video. Of course, it doesn't affect your explanation. The hum will be cancelled, the guitar signal will be doubled.
Yes, I thought I might have that the wrong way around ;-)
Tnank you!
Here's my take on 'String Theory ': Gimme an 'A'!
nice video man!!, also you can explain the induced voltage in a coil whith the formula $e_ind= -N dF/dt$ were e_ind is the voltage induced in the terminals of the coil, N is the numbers of turns of the coil and dF/dt is the rate of change of the magnetic flux perpendicular to the plain of the coil, the minus sing is bc the induced potential oposes to the change in the flux.
by the way, the commentary at the end of the video about how each parameter afect the inductance of the coil are excellent!!!
@@juanchirino7135 Thank you!
Awesome breakdown!
Thank you!
Thanks for all your superb explanations and diagrams.
Thank you!
Thank you for taking the time to put this together. I work in a well known custom shop making guitars. I make the pick-ups, and I’m currently in the process of writing a manual for future staff that get trained in this area.
I do have a question, can you recommend any books out there on the subject?
Thank you! It's hard to name a specific title. Before I made these videos I had been brushing up on classical mechanics, with a bit of a focus on electrodynamics.
You are legend, great videos. absolutely inductance is by far more important then resistance regarding characteristics - meaning it tell us more so We can ''imagine'' how it will behave. Pickup is nothing more nor less then a mic made in such way, it works in same principle as mic, speakers and headphones etc.
how those strings will vibrate will depend from material of bridge, and above all of guitar aka body+neck. Of course material with which we pluck the strings nails, flash or pick. So pickup literally mic it up aka collect the sound, it can be used as mic not as great mic but would work OK 100%..
As electronic engineer and a person who make pickups etc i found it that famous pickup sellers/winders sell myths to people. It is sad a absurd that people who know things or understand like you do have never runed for $ which is OK, while others who sell dreams and lies will sell a simple pickup for 500$ wouldn't any sort of moral brakes or norms.
Complete industry in based on that even in guitar magazines they feed the myths. Anyhow thx for this videos, wish you all the best.
Thank you! I always did and still do get a kick of trying to figure out how things work. Physics for the win!
Thanks for the clear explainations :)
I'm a newbie guitar tech student. I need the education.
Thank you!!!! This was a lot of work for you and I appreciate it very much. Thanks for getting into the physics of what is really going on. Well done!!
The main principle is faradays law... not lorentz...
really a wonderful explanation with the graphics and beautiful narration, thanks!
Yo this was a great video, im a guitar player and im doing a project on how guitars work for my physics class. This video was really helpful for that and also really interesting at the same time so thank you.
The magnet of the pickup can lost magnetism or how it retain it ?
Yes, magnets do lose their magnetism over time; alnico faster than ceramic but alnico magnets can be remagnetized.
I took a physics electromagnetics class back in 1984 and never understood the stuff because it was so theoretical. It would have been nice if the teacher had knowledge of some practical uses for the stuff , but I only see the practical uses thanks to youtube. I don't understand how a tool and die maker knew you could amplify the noise using that setup back in the 1930s. crazy!
My question is, what if you had a super strong magnet? Like the ones used in computers? How would this effect sound or playability, if at all? Ive been curious about this for a while
The stronger the magnet, the higher the output of a pickup but if the magnets are too strong they start interfering with the vibration of the strings, dampening them or even causing out of tune overtones. You can experience this when you put a pickup too close to the strings.
That being said I think in some modern pickups neodymium magnets are used but there are always limits to how strong the magnetic field can be close to the strings.
@@aaronstonebeat yes! That was their name. I couldn't remember it off the top of my head. Well, dang. I thought I had a genius idea for new pickups 😂 thanks for the explanation man!
@@vangoghsseveredear Thanks for your question and for visiting this ancient channel ;-)
So if I'm getting this correct, the vibration of the string across the magnets create an alternating current, which is the signal that gets amplified and listened to?
Yes, that's it!
@@aaronstonebeat Super awesome! thanks for the reply! :)
You could provide a great voice-over for "Count Dracula". :-)
Regarding what's happening with the string, magnet, & copper coil, here's how I would describe it:
1. The energy used to put the metal string into motion is the beginning.
2. As the string moves & vibrates, it, being a ferrous metal string, conducts & concentrates the magnetic field within itself, & it therefore consequently disrupts the normal magnetic field that encompasses the copper coil.
3. That change in the normal magnetic field proportionally affects the free electrons within the copper to cause a force (Voltage) & a movement of charged particles (electrons) to move & ripple through (current (A) flow) the copper.
4. That V & A is what is conducted into an amplifier before it is conducted to a speaker for our listening delights (hopefully).
hth!
Right on the mark!
About the Dracula comment, the electrodynamics comments, or both comments? ;)
zeffur
String theory? lol
Great introduction. Thanks.
XD!!!
Thank you so much for sharing this! I'm a physics professor and novice guitar player and I've been looking for a more in depth explaination of the physics behind guitar pickups. This has been extremely helpful and I can't wait to share the information with my students!
You don't have to resort to quantum mechanics give a satisfactory description of the phenomenon, and I'll suppose you said string theory as a joke about guitar strings, cause that would be like trying to use the concept of brownian motion to explain hurricanes. All you need is Maxwell's equations to describe the behavior of the magnetic fields involved.
Can you make a video theory lesson about guitar pickup magnetic heat treated process, magnetic impulse time response, magnetic Coercivity. I would like to know the theory behind guitar pickup magnetic heat treated process and what it does and also how to change the magnetics impulse time response which is the time interval of the guitar string to the pickups output voltage/current and the magnetic coercivity is the picking sensitivity. The LOWER the magnetic coercitivty the easier the pole piece is magnetized, but why?
This is like listening to Christopher Walken's impression of Count Dracula. Love it!
Thanks, I guess ;-)
Absolutely, man. Fucking cool voice you got there. And I learned a lot about pickups too.
very informative, indeed.
I have a legit question: the electricity out of the pickup is alternate. In pickups specs, the label + and - the start and the finish of the winding. With the north to the strings coils, start is + and finish is - , and with the south to the strings coils, the start is - and the finish is + . Can you explain that, please? I have further questions, but if we can begin with that it would be great. Thank you, I loved the video!
When both pickups are switched on at the same time they are humbucking because of this construction; the coils are out of phase because plus and minus are reversed (canceling external interference) but the signals are in phase because the magnets are also reversed.
@@aaronstonebeat Thanks for replying! I know about humbuckers, my question is not about them. In my question im just talking about a single coil pickup that you can put a string in one side or the other, or just use a pickup with north up, and then change for another with south up. Can you read the question again with this in mind, please?
@@aaronstonebeat I also know that the winding is the same, you just use one side or the other of the magnet and then the resulting winding direction is clockwise or counterclockwise. But if you have the string in the north side the label of start is + and the finish is - , but if you have the string in the south side, the start is - and the finish is + , and there is where my question is leaning onto.
@@diegopedroroldanmerino4208 Two single coil pickups can also be humbucking (they often are), that is the only reason for the electrical and magnetic reversal.
If only one pickup is on it doesn't matter. If two pickups are on and plus and minus are connected the same but the magnets point different ways they will be out of phase; and if the magnets are oriented the same but plus and minus are reversed they will also be out of phase.
@@aaronstonebeat FORGET ABOUT HUMBUCKERS! it is just one pickup in this example, my question is not about two pickups conected together!!!! If I put ONE single coil north up clockwise winding, the start is labeled as + and finish - in the specs. Imagine we REPLACE it, and put just one pickup in this imaginary guitar, wich is south up, counterclockwise winding, the start will be labeled as - and the finish +, and that is what I don't know why it is, do you? Why the start will change to be labeled from + to - depending on where the string is vibrating ("where" meaning the north pole or the south)?
Hi there, really love your video series! I do have a question though. When you say 'More ferromagnetic core material = higher inductance', do you mean that using pole pieces with a .195" diameter instead of .187" (assuming the same height) would lead to higher inductance? Thank you!
Yes, but it'd be hard to say how much.
very good video also... a good start for a saturday morning
Most excellent sir.
Thank you!
Thank you so much. !!
Amazing Explanation..
Thanks!
sounds like a dutch christopher walken
I loved your work in "The Dark Knight Rises" ;)
They discovered this before the first American civil war
I am a luthier who is beginning to build my own pickups from scratch. Like most enthusiasts Id like to experiment with differ winding configurations, magnetic strengths, number of windings, etc. Do you have any advice for me, any ideas you would like to see tried?
Mark Von Sting... 9 YEARS AGO..
I very seriously doubt that you still have this account.
But nevertheless, since it HAS been so long;
I'm now quite interested on how your journey as a luthier, moving towards custom pick up builds has worked out for you?
That is if you are still there and care to share.
MARC VAN, when you put a Dummy Coil in series it cancels out the HUM noises from a single coil pickup. Why does a Dummy Coil cancel out the HUM noises when there is no magnets in the dummy coil have no magnets and the dummy coil is NOT reversed wound. So how does the Dummy Coil reverse the polarity phase of the HUM noise?
It only works if the dummy coil IS connected out phase with the single coil pickup.
Any piece of metal, so also a wire or a coil, will be an antenna that picks up electromagnetic waves (hum); only in combination with a magnet will a coil transduce a signal from a vibrating ferromagnetic string.
thanx
Thank you!
This is exactly what I wanted to know, very helpful thank you!
Les Paul is the goat 🐐
As a string moves back and forth over its pole screw it seems the response in the coil would be the same as it moves off center in either direction. Would this not produce a 2nd harmonic? There must be a gradient in the magnetic field to get the fundamental response.
That is probably a great question and on one hand I'm not sure how to answer it while on the other I'm sure you're right.
But then the whole series of harmonics is present in the vibrating string to begin with so it will also be in the vibrating magnetic field.
Isnt it so that the magnet is only there to magnetize the string. When magnetized the vibration of the string causes a vibrating magnetic field being picked up by the coil resulting in an osilating voltage. It is not the string infuencing the magnetic field of the core as explained here.
When the string is magnetized you actually dont need the magnet anymore so a coil with only ferromagnetic core would work equally (until the string losses its magnetic strength).
I think that is partly true. The strings do get magnetized and cause inductance in the coil when vibrating but all on their own the part of the coil away from the strings would be a lot less affected than the part close to the strings.
Sir, thank you for this lesson, it is very easy to understand
Thank you!
Not so easy to really determine, I think. At rest there is a flux depending on the magnet strength but in action it is the changing magnetic flux that counts. This depends on a few thinks that draw quite a complicated picture if you try to describe reality: the frequency and amplitude of vibration of the string(s), the thickness/mass of the string and is ferromagnetic properties and the surface of the coil windings.
I'd try to go for one frequency and amplitude from a signal generator to begin.
i just learned Lorentz force by using right hand rule, but I could not figure out blue, red, black arrows in your video.
The strength of the magnetic field changes perpendicular to the wire of the coil, either inward or outward and so and electrric field is induced in the wire, either one way or the other, perpendicular to the direction of change of the magnetic field.
Do the strings have to be metal???
Yes, they do. The strings excite the magnetic field of the pickup; they wouldn't do that if they were made of a nonmagnetic material.
They have to be conductive, so a grosso modo, yes.
A moving electric charge causes a magnetic field (this is the aim of it).
You're looking for a variable magnetic field in order to get current in the wire.
@@jonlasarte9690 it's not that they have to be conductive - they have to be ferromagnetic.
best explanation i could find
Amazing!!
A pickup can work exactly the same without magnets if the string is magnetized
True, that should work. Time to buy a set of magnetic strings and test it ;-)
Or pass a current through the strings. That will create a magnetic field.
The perfect video for my research
your videos are a huge resource thank you
This guy sounds like the Bill Gates impersonator from Nathan For You.
This is super fascinating and helpful, but I have one question that I can't seem to find an answer to anywhere. Why does one of the poles of the magnet have to face the string? I know that the poles of the magnets tend to have the strongest pull, but would turning a magnet sideways so that the string is vibrating through the center of the magnet still yield a useable output?
Notice how all magnetic field lines cross the strings in the same direction; if the magnet were on its side one half of the pickup would be out of phase with the other half.
In humbucking pickups you find bar magnets on their side often but they are underneath the pickup; pole pieces extend the magnetic poles towards the strings and each set of pole pieces has its own coil.
Also in P90 pickups there are two bar magnets on their side underneath the pickup; in these pickups the same pole of the bar magnets is held in place against the pole pieces which extend that pole towards the strings.
@@aaronstonebeat Oh, that makes a lot more sense! I've been trying to see if there is a way to modify an electromagnetic pickup to work on a bowed instrument like a violin or a cello. Guitar pickups don't work well on bowed strings because guitar strings seem to pick up movement towards and away from the magnetic pole and a string that is bowed vibrates side to side, not up and down.
I was talking to someone today about it and they showed me a picture of an electromagnetic pickup for a violin that I had never seen before, but it only had three pole pieces and they all went between the strings rather than underneath them to compensate for the difference in motion. Do you think that set-up would be able to pick up a decent signal from a bowed string?
@@aaronkath6083 You are correct about the direction of motion of the strings relative to the pickup. From there it would seem to make sense to have the pole pieces between the strings but I am totally unfamiliar with pickups for violins. I can imagine the pole pieces rising up between the strings while the coil would still be in the traditional place; so basically a guitar pickup with extended pole pieces.
Do you have a brand name or something that would help finding pictures of such a device? You've made me curious.
Brilliant video thanks
@Pana6Ion
No, wider turns enclose a larger surface; more magnetic flux passes through a larger surface. So given the same amount of turns and the same magnetic field strength a wider coil will have higher inductance.
@custardpiekashmir
De resonantie-eigenschappen van de gitaar beïnvloeden de manier waarop de snaren trillen. Zo hoor je bijvoorbeeld heel duidelijk verschil in het versterkte geluid tussen een holle en een massieve gitaar.
I'm hoping you have one about pickup polarities and wiring, with and without pull-pots. You did a pretty fair job here, FAR better than most. Cheers
Isn't string vibration more or less normal/perpendicular to the magnetic field as you have it depicted in 2:55? If you pluck a string, it vibrates side to side, perpendicular to the slug. But it would still move within the magnetic field of the slug I think.
Actually the strings vibrate in all directions but it is mainly the movement to and from the magnets/slugs that causes the magnetic field to vibrate with the strings and induce voltages in the coil.
@@aaronstonebeat Yeah I assume they would, but vibration in the horizontal plane would seem to be the most prominent frequencies, no?
Also, I wonder if you would get a stronger/more sensitive signal if the slug were played sideways next to a string.
@@EatScrabbleGoo That might be a nice experiment; you could try to mount a pickup next to a string and find out if there is a difference.
But it wouldn't be very practical, would it?
@custardpiekashmir
Gebruikte materialen hebben ook een invloed op het geluid maar ik kan me zomaar voorstellen dat een glazen elektrische gitaar prima klinkt. Er zijn ook mensen die gitaren van aluminium of staal maken; er circuleert ergens een filmpje van een gitaar waarvan de body van een blok beton is gemaakt.
Maar ook gitaren van naaldhout en hardboard (bv Danelectro) hebben een karakteristiek en eigen geluid dat sommigen zeer waarderen.
Yes I like !
Dont know if i understand this, so i need 2 ask u a q:
If the string was made up of, say 4k turn of isolated wire, starting & ending on the brideg u could throw away the pickup coil, and instead use the string itself as the pickup, if it was connected to the amp as the 'coil' circuit..?
I mean, any (fe-based) conductor will be induced with a current if moving trough a magnetic field?
Ok, thanks for this xellent video!
string theory hahaha
according to Lenz the blue arrow should be the initial direction of speed of electrons, rectangular to the magnetic field lines, that causes the lorentzkraft. you describe it as direction of movement of the field lines. maybe it'd be better to imagine it as the increased/decreased pull of the magnet on the copper wire, wich in theory causes micro contraction/relaxation of the copper wire around the magnet. this way you could explain the direction of induced current with the usual three dimensions (magnetic induction, lorentzkraft, and speed (and direction) of electrons).
But copper is not really magnetic, hardly anyway. Electrons have a charge and respond to changes in the magnetic field.
Pickup wire can be potted or cast into epoxy resin and have virtually no freedom of movement at all and still produce a very good guitar signal.
So why?
Honestly because I do not understand how you can simply exchange these two dimensions: Direction of change of the magnetic induction B speed and direction of travel of electrons (as in the general formula for the Lorentzkraft). Is there an explanation for why they are equivalent here?
Hey there, I have this school project! I was wondering if its possible to find magnetic flux in my electric guitar knowing its EMF(voltage) using Fraday's law...How could I do that. If you can please tell me, i would appreciate it! Hope you understand my question which I think you do!
This sounds like a bad audition for a male counterpart of Siri or Alexa
We are all magnets
Thank you!
Mate! great video. i remembered studing this in the Phisics lessons 15 years ago...so, dont remember that much anymroe :P
Look, reagarding the copper wire around the magnet: we need several turns in order to get higher induction? The differnece in potential is measured from one point to the other point of the wire?? thanks
So what you're saying is pickups make sound go boom
Yes, in principle you are right. I guess it would just be impractical to make a string like that.
@pantera2004hellbound
They represent the 'pole pieces', either small magnets or metal slugs with a magnet underneath.
Hallo Marc, kun je ook het geheim uitleggen van het allereerste commercieel verkochte horseshoe element van rickenbacher, uitgevonden door George Beauchamp, en gepatenteerd in 1937. Ik probeer al enkele jaren om zo een element te maken, voor mijn lapsteel gitaar, met wisselend succes. Groetjes Jean uit Belgie.
Beste Jean,
Het principe is niet anders dan dat van 'normale' pickups; een spoel in een magneetveld. Alleen zijn het hier twee U-vormige magneten, met gelijke polen boven en onder de spoel (beide noord boven of beide zuid boven).
Het geheim zit 'm ongetwijfeld in de dimensies, het gebruikte wikkeldraad, het aantal windingen, de sterkte van de magneten, het materiaal van de poolschroeven.
Ik zal je vast niets nieuws vertellen en de juiste maten van al die ingrediënten weet ik niet. Is daar niets over te vinden in het oorspronkelijke patent?
Wel tof om te proberen zoiets te maken!
@@aaronstonebeat Bedankt Marc, ja ik ken het aantal windingen (+/- 5000) van .38 AWG draad, dan kom je uit op ongeveer 1.8 K Ohm DC weerstand. Ik heb ooit een Rickenbacher gekocht en daar heb ik alle maten van gebruikt. Het enige wat ik niet weet is van welk materiaal de 'poolpieces' gemaakt zijn, en het exacte soort staal. Volgens sommige amerikaanse sites is het O1 Toolsteel, wat in Europa overeen komt met 1.2510 gereedschaps staal. Verder heb ik nog een stuk of 5 andere soorten gereedschapsstaal geprobeerd met allemaal verschillende percentages koolstof, silicium, mangaan, chroom, vanadium enzovoort. Maar blijkbaar is het percentage Wolfram of Tungsten belangrijk, en laat dat nu niet, of weinig aanwezig zijn in het meeste soorten gereedschaps staal.
Het is waarschijnlijk daarom dat ik deze staalsoorten onvoldoende gemagnetiseerd krijg.
Ik ben wel al heel kort bij het geluid dat ik zoek, en dat kun je horen in de link hieronder.
Dit is een oude jaren '30 rickenbacher.
ua-cam.com/video/8ArwAqM88Kw/v-deo.html
Groetjes
Jean
@@germona Ik heb ooit wat geëxperimenteerd met het maken van pickups; gewoon om te kijken of het überhaupt kon. Als 'pole pieces' gebruikte ik boutjes van een bouwmarkt; mijn test voor bruikbaarheid was of ze voldoende aan een magneet bleven plakken 😁
Sommige staalsoorten zijn maar zwak magnetisch; een hoop 'goedkoop' standaardspul is ruim voldoende ferromagnetisch.
Voor een element is 1,8 kOhm niet buitensporig veel. Maar ik weet uit ervaring dat het heel mooi en helder kan klinken.
Actually the magnetic field changes when the string moves because the magnetic field lines prefer travelling through ferromagnetic materials like the string. When the string is nearby it basically sucks the lines in distorting the magnetic field. The closer it is to the magnetic lines the more it can suck them in, resulting in a changing magnetic field, and that's what induces a voltage in the coil.
You can test this by very very very carefully sliding a ferromagnetic material (mild steel) on top of the pick up, which will suck the magnetic lines in and there wont be anything left for the string to distort. But be very slow to avoid generating a large voltage as you distort the magnetic field.
I agree: string closer, magnetic field contracts; string farther away, magnetic field expands.
@@aaronstonebeat your explanation was very good, I just thought I'd expand on this part :)
@@akosszollosi6159 Thank you for your contribution to the explanation!
You are a cool guy to help us musicians with the scientific underpinnings of pickups. I liked how at the beginning You made the point that much of this was understood a century ago, and other parts might require Quantum Mechanics or even string theory yet the deeper one dwells, more questions arise and so on.
The guitar string isn't pulled away from the pickup, it moves perpendicular to the pickup. Also if I remember my right hand rule correctly (from 30 years ago) the current will always flow in the same direction unless the poles of the magnet are changing. So the guitar string vibrating only causes the strength of the current to fluctuate not the direction.
I thought the string vibrates in all directions at once
Nice explanation. If I understood the Lorentz force correctly I would assume there is also an electric current in the string itself (because it's a conductor moving in a magnetic field). Is that correct? And if yes, why it is not used to pickup the tone.
You are right but amplifiers (tubes or transistors) respond to change in voltage, not current. Also the induced voltage in a string is very small because it passes just once through the magnetic field whereas the wire of the coil passes thousands of times through the magnetic field.
Thanks Marc, I have a personal bass guitar project, where I would like to install the pickups along the strings instead of across them, what do you think about?
That could be made to work but it might have disadvantages; you'd need at least two pickups where normally one would be enough and the pickups would have to be very similar in specifications. I think I would build a setup where I could mount the pickups above the strings in various orientations and configurations to test the differences in sound and decide whether it is worth the trouble.
@barnoguttlin
Dank je, Barno! Engels zingen blijkt vooralsnog makkelijker dan Engels spreken ;-)
Thanks! You are right on both points: the more turns there are the higher the inductance and the potential difference that can be induced between the ends of the wire.
what are those "dots" called on the pickup?
Very helpful,Have a great idea for a new concept in pickups and this really helps
THANKS..:) what does influence in "guitar sound".....My theory that type of wood cant influence on it...but everybody I know says different...
wood definitely has nothing to do with the guitar tone, a while ago +willseasyguitar did an experiment with a frequency generator proving that, you should check that out.
The pickup, nut material (bone,brass etc...), the bridge material and tuners.
Basically anything the string is in touch with affects the tone.
A brass nut will give you a brighter tone for example.
Tonewood is only a myth for marketing purposes only.
@Pana6Ion
Sure, if I can I'd be happy to.
It has been demonstrated with a magnetless pickup that it is in fact the magnetic field around the string moving through the coil that induces the current in the coil. Search for zexcoil, there is a fuller explanation.
www.guitarworld.com/gear/how-does-a-guitar-pickup-really-work
I have searched for 'Zexcoil' and found they use individual coils and magnets per string. Innovative!
If there were no magnets where would the magnetic field around the strings come from?
Also. Search this article for the word nuts for the salient paragraph. www.seymourduncan.com/blog/the-tone-garage/seymour-w-duncans-interview-with-seth-lover
@@tochriss I've read the article and I find it inconclusive about how the strings are magnetized; still, some form of change in magnetic flux makes a coil induce a change in voltage.
So what's different from that than what I talk about in my video?
@@tochriss Put a pickup without any magnets in your guitar and hear what it sounds like.
Guitar lessons with Walken
Very interesting. Thanks very much.
that would be an insulated wire though I presume... wire alone isn't insulated and wouldn't work, right? It would immediately short out and there'd be no coil i.e. inductance effect.
Although i am not sure, that's what makes sense
You're right. The wire in the bobine is isulated. If foy any reason in the middle of the coild the isolation brakes, the RC will reduces proportionaly and the output would be very weak or nule.
I am experimenting on a 5.1 stereo surround chorus effect using an acoustic guitar and piezo and other mics to create a 6 output signal. My first setup was to use 4 mics inside the gtr 2 upfront and 2 in the back to get a front L/R stereo and back L/R stereo with the under the bridge pickup used as the center and sub.I also want to try a second setup using individual coils for each string. The low E would be the sub A would be back Right D would be back Left G- front Left B front-Right little E-center.
My ? is what type of coil should I use for a one string pickup using 6 separate magnetic fields for each string? Is there any Electromagnetic coils that would be good for this or would this have to be hand made? Any helpful hints that I could try? I also am looking ahead to phase and impedance also delay and chorus effects then preamped and sent out as 3 1/4" TRS stereo L/R low impedance signals to the mixing board and routed to there assigned speakers?
Any Thoughts on this would be very appreciated!
I know individual pickups for each string are used to trigger guitar synthesizers, so they do exist. Maybe that is something to look around for? It wouldn't be that hard to make such pickups by hand though.
A thing I once tried: take a head from a cassette player, hold it close to a string and have a magnet nearby and you get a signal! Those are small coils that produce only a low voltage but if you're using preamps and it's for acoustic sounds that should be no problem.
Those are the first thoughts that come into my mind.
Marc van Oppen Thanks Marc Im gonna try the cassette head path. Could you give more info on how the setup would be? Im guessing a head for each string?And were is the magnet? Under the cassette head i'm guessing?
I have to ask? You thought 6 mics in a acoustic guitar is gonna be Noisy as Hell didn't you Marc? But you think 6 pickups on each string would produce better results? It would be easier to do? Would you place each string like I planned in the speaker arrangement or would another arrangement be better? And last ? is there gonna be any problems with phasing or polarity in creating a stereo surround sound effect?
Sorry about all the ?'s but your pretty smart about this topic and you seem to be a experimentalist like myself ?LOL!
Thanks Marc that was alot of help!
I'll let you know how things turn out!
Fourstringplayer Bassman
First of all: it is a thing I tried only once because I expected it to work; but it was just one head and one string. Indeed I held the magnet underneath the cassette head. Microphones will give a more natural sound but they also will pick up all the noise from handling the guitar. 6 Pickups will allow you to hear each string virtually individually and with a lot less noise.
How to place the strings in the speaker arrangement? I wouldn't know, I'd have to try. But you have a plan; so try that and see if it needs adjusting.
Sounds like fun! Good luck!
Great Vid!!! Maakt het allemaal een stuk duidelijker, Thanks!