No jokes here folks.

The heading just about says it.

What exactly is a pickup?

Or for that matter, what's a cabinet?

Sorry to all the veterans who're wasting their time on me.

-S

a pickup, in it's simplest form, is a magnet wrapped with wire. when a magnetic metal (like a string) passes through the pickup magnet's magnetic field, an electrical current is induced in the wires that are wrapped around the magnet. the frequency of this current corresponds with the frequency (back-and-forth speed) that the string was passing through the magnetic field.

a cabinet, other than a place to hold plates or guns, :D, is the term for the box that holds 1 or more speakers and possible some passive crossover components. usually a box that has both an amplifier and a speaker is called a combo or combo amp.

interestingly enough, speakers operate under the same principal that pickups use, only in reverse. at the heart of a speaker is a magnet with a coil of wire wrapped around it, only this time the wire is fed an alternating current, and this induces a variable magnetic field, that will cause a piece of metal to vibrate at the same frequency as the current applied. attached to this "piece of metal" (shaped like a cylinder, called a "voice coil") is the speaker cone, which vibrates and thus produces the sound that you hear.

Thanks for the reply, John.

But I'm still a little lost, is the pickup a separate thing altogether or is it actually a part of an amplifier or what?

-S

the pickup is the black rectangular thing under your strings on your instrument. inside there is the magnet wrapped with wire.

for some reason i'm feeling pretty zen today :D besides, i'm not sooo old that i can't vaguely remember what it was like to be totally ignorant. :D (you know, like last week )

A pickup is a big car with a flat back, big tyres and 4 wheel drive.

Pickups, the way they are described above, are only used on electric basses, and are sometimes covered by a plastic or wooden plate, giving the instrument a nicer look. Pickups are also available for acoustic bass guitars and double basses and they are more like a microphone. Sometimes inside the bass and sometimes placed on the bridge.

A cabinet is a speaker box. Simple as that.

Totally ignorant? Yikes, that hurts.

just kidding, stingisanoldman. actually, it takes an enlightened individual to want to learn and realize they need to ask for information. i was just saying that i responded as best i could because i remember the not too distant past when i didn't know what a pickup was.

ok, i'm getting old, it was more like the kinda distant past. but you get what i mean, right? :D

I know, no offense taken. It takes a lot to irk me. In any case thanks again for the help. I've gotten plenty of information from this site in the past week or so I've been a member, so again thanks to you and everyone who's explained what pickups and everything else I've wondered about is.

-S

i thought a pickup was the thing that "picked up" the sound of the strings vibrating and put it through the amplifier, and thats what the cord is for. you ppl are all " the magnetic feild of the wires and the magnets are all transmitted through electrical impulses..." the guy asked a simple question and your showing off just cause you can, you, my freind, are an asshole.

Welcome to www.lakland.com;)

Damn, man, thank god. That's all I needed to know. Thanks mayfairmistress. (Hope I spelled that right).

-S

Originally posted by mayfairmistress
i thought a pickup was the thing that "picked up" the sound of the strings vibrating and put it through the amplifier, and thats what the cord is for.


well you're wrong. the pickup doesn't "pick up" the sounds, it picks up the vibrations through a magnetic field. like i said.

but then again, i coulda just said, the little black box that "listens to your strings" :rolleyes:. in fact, i coulda just ignored the question - i know what a pickup does. i thought i would help out a beginning player with the _truth_, instead of feeding him some bs.

did i miss something? are we on aol?

you ppl are all " the magnetic feild of the wires and the magnets are all transmitted through electrical impulses..." the guy asked a simple question and your showing off just cause you can, you, my freind, are an asshole.

well "asshole", i explained it that way because that's what pickups do. the explanationt that i gave is the easiest there is to it. some things in life can't be described in the 5 words or less Mtv news version. of course i coulda just said "it picks up the sound of the strings vibrating" but then i would just be spewing bull$hit, like you.

i'm not your "freind" kid, but i will offer you some "freindly" advice. keep that attitude and you are going to find yourself making many enemies here. furthermore, most of these forums are moderated. vulgarity like that will not be tolerated by the moderators. the only reason you haven't heard about it yet is that the pickups forum is presently unmoderated.

grow up or go home.

i said the sound of the strings vibrating. i am right. get over it. if the guy doesnt know what a pick up is do you really think that throwing all that "magnetic feild" junk in his face is gona help him? use some common sense dude. and the "my freind" thing is a figure of speech. and that 'im not your friend' thing was pretty 8th grade-ish. okay so dont tell me i need to grow up just b/c i seem to understand what this guy is saying a little more than you do. okay, so were both childish, get over it.

and giving him a simpler, more understandable, explaination isnt lieing to him. i told the truth, if he wants to know all that technical crap i think he can find out for himself. he just wanted to know where it is and why its there, not how it works and what its made out of and why its made out of what its made out of. i dont think he plans on making one himself anytime soon.

sorry about calling you an asshole. im not normally this stupid but your reply to the dudes question made me kindof angry. im truly sorry and i hope you accept my appology, however, i am still right. but then again so are you. but i just dont belive that he wanted to know all that. and to that paul dude that sent me that e-mail, when i say technical i mean stuff that isnt nessisary in knowing what somthing is, i didnt mean that magnets are complicated i meant that its usless information unless you have alot of free time and plan on creating a pickup yourself.

no, you're not right. but i do accept your apology :D, i've been called worse, often in fact.

sound is vibration of _AIR_. the pickups detect and transmit vibrations _WITHIN A MAGNETIC FIELD_. here's an example. try speaking close to your strings with your bass plugged in. you are making sound, but the pickup isn't detecting and amplifying it. if that explanation was sufficient ("it detects the sound of the strings vibrating" ) then it should also detect the sound of your voice too, right?

saying a pickup detects and transmits sound, while seemingly correct, is not. it's like saying the earth is flat, cause that's what it looks like.

the truth is never useless.

i know what it does and how it works but this guy doesnt and i was trying to make it simple. CAN YOU UNDERSTAND THAT?

Originally posted by john turner
no, you're not right. but i do accept your apology :D, i've been called worse, often in fact.

sound is vibration of _AIR_. the pickups detect and transmit vibrations _WITHIN A MAGNETIC FIELD_. here's an example. try speaking close to your strings with your bass plugged in. you are making sound, but the pickup isn't detecting and amplifying it. if that explanation was sufficient ("it detects the sound of the strings vibrating" ) then it should also detect the sound of your voice too, right?

saying a pickup detects and transmits sound, while seemingly correct, is not. it's like saying the earth is flat, cause that's what it looks like.

the truth is never useless. some pickups can work like a mic if you scream into it it will go threw to the amp i seen it done before,quite frankly it confused the me,how is that explained ?

m'kay... how bout reading my second reply, when he finally made his question clearer? or did i still not UNDERSTAND HIM? :rolleyes:

Originally posted by ross
some pickups can work like a mic if you scream into it it will go threw to the amp i seen it done before,quite frankly it confused the me,how is that explained ?

that's called "microphonic" pickups, ross. what's going on is that some piece of metal or some other aspect of the pickup itself is vibrating from the force of the sound of your voice. this is bad because as this metal piece vibrates in the magnetic field of the pickup, it interferes with the regular workings of the pickup, thus causing the pickups to lose some of their response, and their sound will suffer.

although there are some pickups that are designed this way, like some gibson les paul humbuckers, this is not a good thing - microphonic pickups are basically considered either "broken" or "cheap and crappy."

look, dont act like i have somthing against you. i just want to know what you have against me, and my simple explainations that you think are wrong. i dont get you.

Welcome to TalkBass, John:D

Pickups work in a specific manner. Sorry. If you put gut strings on a Warwick Thumb bass, good luck on your next gig:D If someone wants a simple but incorrect explanation of their (pickups) workings, cool. Maybe later he can spread that knowledge to others. Cool. Sometimes you can only get so simple in a response. Ask for further clarification if you still don't get it. OK?

This is why some people think Flea invented slap. Cool


:cool:

Originally posted by mayfairmistress
look, dont act like i have somthing against you. i just want to know what you have against me, and my simple explainations that you think are wrong. i dont get you.

I'm sure it has nothing to do with what you called him;)
I'm sure you meant it in a good way.

In reference to "Electric basses" which is what this side of the site is about, it's not about picking up "sound", it's about picking up vibrations, either through a vibrating Ferrous (containing Iron) material or mechanical vibration (Piezo bridges). Of course I could be wrong.

mayfairmistress...John is correct. And thats the most succinct defintion there is. You can tell hes correct with the magnetic field...here, try this: Put a nylon string on your bass, in place of maybe the G string. You can find one of suffiecient guage. Then play it. Do you hear it coming through the amp? Nope. Its non-ferrous, which means it wont be picked up or detected in a magnetic field, because its a non-metal mixture. Metals are made ferrous by combining two or more metals, and depending on the conbination of metals, the mixture will be more or less magnetic. In the case of strings, they are not magnetic enough to stick to a magnet, because then theyd just stick to the bridge and the frets. See?

[Edited by MegaAngus on 08-27-2000 at 12:37 PM]

HELLO, PEOPLE, I GET IT! shut up, get over it.

Take it from me, talk like that and nobody will like you. Please dont be rude. People like nice people. :)

One more round of cranium-thickener for the house! It's on me:D

And it's still two days till the full moon. :)

John, you have the patience of Job. :)

Before anyone gets bent out of shape, I didn't mean that as a slam. ( I say as I grab for my asbestos suit.)

Just a useless point but it gets me on topic: So far as the string producing an output, it really doesn't matter whether the string is ferrous or not. It only needs to be an electrical conductor. Copper is non ferrous but generates a voltage when used as the armature winding material in a generator. It's the exact same principal.

See? I told you it was useless.

My God...what have I started!?

-S

hi mayfairmistress. i have nothing against you whatsoever. i do however take talk bass seriously, and i answer questions that i can as seriously as i can. i'm really not an asshole, honest :D, but i am very _VERY_ serious about my bass playing - right now it's the only thing i do. this forum means a great deal to me, as far as sharing information is concerned. it's not just a fun place to hang out, at least not for me, and not for many others either.

i see that you are new here. welcome,:D. i am sure that you are not new to the internet, though, or to discussion forums. this one is populated by a wide range of members, ages from 12 or 13 to their 50's, who all share a love of playing bass. one thing for you to keep in mind as you are here is to remember that people from all kinds of backgrounds frequent these boards, and unfortunately they will judge you here, not only by what you say, but how you say it. it's not fair sometimes, but it is true. something to keep in mind.

you come here obviously because you are interested in bass playing. i personally am glad you're here - i think that everyone who goes through the trouble of coming here will have something positive to share, and i look forward to your input. however, please remember that you will get a warmer welcome if you keep the sarcasm out of your posts, and the vulgarity too.

Originally posted by pkr2

Just a useless point but it gets me on topic: So far as the string producing an output, it really doesn't matter whether the string is ferrous or not. It only needs to be an electrical conductor. Copper is non ferrous but generates a voltage when used as the armature winding material in a generator. It's the exact same principal.

See? I told you it was useless.

but i thought that was more because of the effect induced from maxwell's equation - the same reason why pickup windings can be, and often are, copper. i was always under the impression that the displacement throught he magnetic field can only be caused by ferrous/magnetic materials. i could be wrong though, i never did pay that much attention in motors class, back in the day :D.

but i thought that was more because of the effect induced from maxwell's equation - the same reason why pickup windings can be, and often are, copper. i was always under the impression that the displacement throught he magnetic field can only be caused by ferrous/magnetic materials. i could be wrong though, i never did pay that much attention in motors class, back in the day :D. [/B][/QUOTE]

You probably are right,John. It's been a long time since electronics and I've forgotten probably as much as I remember. It looked good on paper though. :)

By the way,John, Thanks for volunteering as a new moderator. I can't imagine a better suited person for the psition. Count on my support.

thanks. i wish it coulda happened under better circumstances. but hey, that's life. :|

you'd think, huh? :D

life is too important to take yourself seriously.

ummmmmmmmmmmmmmmmmmmmmmmmmmm

the relivance is killing me

THAT WORKS ON SO MANY LEVELS!!!!!!!!!!!!!!!!!!!! LMAO!!!!!

Originally posted by john turner
Originally posted by ross
some pickups can work like a mic if you scream into it it will go threw to the amp i seen it done before,quite frankly it confused the me,how is that explained ?

that's called "microphonic" pickups, ross. what's going on is that some piece of metal or some other aspect of the pickup itself is vibrating from the force of the sound of your voice. this is bad because as this metal piece vibrates in the magnetic field of the pickup, it interferes with the regular workings of the pickup, thus causing the pickups to lose some of their response, and their sound will suffer.

although there are some pickups that are designed this way, like some gibson les paul humbuckers, this is not a good thing - microphonic pickups are basically considered either "broken" or "cheap and crappy." thanks for clearing that up for me,next time i go bass shopping i'll have to try yelling into the pick up to see if its cheap or crapy :)

i have no idea what your talking about.

I thought I knew the answer to whether the strings had to be ferrous or not, but now I am not so sure. I thought they had to be, but on exercise equipment that uses eddy current braking, the disc that is subjected to the constant magnetic field is aluminum, and the eddy current that is set up by the rotating aluminum disc is what interacts with the permanent magnets. So maybe the vibrating non-ferrous metallic string actually has little eddy currents induced in it that then induce signals in the coil? Any takers?

As for the motor windings, speaker windings, magnetic field thing, as best I remember, the force is actually "inflicted" on the electrons that make up the electric current passing through the windings, not the copper, per se.

Just about everything is more or less magnetic. I saw footage of a lab using thousands of amps of current to magnetically attract a plain old tennis ball to an electromagnet, and it worked. Made the tennis ball act like it was made of steel.

Chris

Okay, this needs to tone down just a little. I think that everyone need to calm, a couple people more than others ( I ain't namin' names.)

If it gets and worse, or doesn't get better, I will shut it down.

Wow, power straight to the head. Cool.:D


Rock on
Eric

Eric: Those words Chris used in his post ain't cuss words. I swear they're not. I looked 'em up in the book.:) :)

By the way, congrats on the mod position. You are now a leader of men.:)

Chris, I don't really know how to explain it. I believe though, that the tennis ball was lifted by static electricity. I believe a conductor has free electrons and a non conductor has no, or very few free electrons. A conductor, when passed through a magnetic field will generate a potential voltage. In a pickup the string passing in and out of the magnetic field generates a voltage thru magnetic/ inductive coupling across the pup coil. This voltage,of course, drives the amp.

I'm sure some of the guys can give a better explanation but that's the general gist of it.

in light of this thread maybe it should be changed to talkbass/physics.com, lol. BUt its interesting stuff i've now been insirped to invent a pickup that runs on tennis balls, j/k

keep the info pooooring in its seriously great stuff

and i totally forget physics was in my handle (its unrelated though- see also off topic threads about usernames)

JP

Originally posted by throbbinnut
I thought I knew the answer to whether the strings had to be ferrous or not, but now I am not so sure. I thought they had to be, but on exercise equipment that uses eddy current braking, the disc that is subjected to the constant magnetic field is aluminum, and the eddy current that is set up by the rotating aluminum disc is what interacts with the permanent magnets. So maybe the vibrating non-ferrous metallic string actually has little eddy currents induced in it that then induce signals in the coil? Any takers?


wow, i would like to hear more about the eddy current braking stuff. time to askjeeves. :D


As for the motor windings, speaker windings, magnetic field thing, as best I remember, the force is actually "inflicted" on the electrons that make up the electric current passing through the windings, not the copper, per se.


yeah, anything that is electrically conductive can induce a magnetic field if it is in the proper geometry.



Just about everything is more or less magnetic. I saw footage of a lab using thousands of amps of current to magnetically attract a plain old tennis ball to an electromagnet, and it worked. Made the tennis ball act like it was made of steel.

Chris

i sure would dig seeing the pickups that would work with a string made out of tennis balls. :D

I did a search for the super magnets I mentioned. It's definitely magnetic force, not static electricity.

Check out the levitating frog:

http://www.sci.kun.nl/hfml/levitate.html

I'm still pondering the "exactly how does a pickup work" question. My best explanation right now has to do with the fact that a voltage is induced in a coil of wire when it is subjected to a changing magnetic field. As the string vibrates, it makes the amount of magnetic flux increase and decrease, which produces a voltage in the coil proportional to, and with the same frequencies as, the vibrating string.

It all comes back to magnetic circuits, which act similar to electric circuits. There is a source of magnetism, and a circuit for the flux to flow through. The reason why transformers are made of iron is because it has a very low reluctance (reluctance is the magnetic version of resistance). You can make a transformer using air as the core, but it wouldn't be efficient for power trannies at low power line frequencies. They are used in radio frequency work, though.

So I propose that the string changes the reluctance of the magnetic circuit as it moves back and forth, thus varying the amount of magnetic flux (analogous to electric current) that couples into the coil, which in turn induces a voltage in the winding.

Anyone buy that for a dollar?

Class dismissed......
Oh, and this will be on the final. :D

Chris

yeah, anything that is electrically conductive can induce a magnetic field if it is in the proper geometry.
=========================
Actually, any two materials, conductive or not will generate a voltage potential if there is relative motion between the two materials. When you rob an amber rod with a wool cloth a magnetic field and a voltage potential are generated. The more conductive the material, the higher the efficeincy. Tennis ball strings probably would work fine if you could vibrate them fast enough in a magnetic field that was strong enough and you had an amp that was sensitive enough.


============================wow, i would like to hear more about the eddy current braking stuff. time to askjeeves.


John, another good example of eddy current braking is a loud speaker. If not for magnetic(same thing as eddy current) braking , a short sustained signal such as the pop you hear when you step on your guitar cord and pull it out of the socket would go boiiiiiiiiing. The interaction between the voice coil and the magnet become a braking system for the cone. Also when the pole pieces on a pup are adjusted too close to the string the string becomes damped and sustain suffers. Again, eddy current braking.
==================================================

soundofphysics.
Your name says it all.
Actually, thanks for the positive input. I'm very aware that this sort of discussion is boredom city to lots of people but it really does pertain to music.

=======================================
John, when the heck do you sleep? :) :)

The link below has a good explanation of pickups. Pretty much the same as mine above, but something I had not thought about, that the electrical signal for strings wavering horizontally over the pickup cause an electrical signal that is twice the frequency of the motion (as the string moves from extreme left to extreme right, the signal goes from min to max to min, and the string has only gone from min to max). Strings moving vertically (moving away from the pole piece and then towards the pole piece) create a signal that is the same frequency. Cool.

http://www.wsu.edu/~aappel/guitarpickups/index.html

Chris

Anyone buy that for a dollar?
=================================
Actually, that's at least a 2 dollar explanation. Excellent explanation.

I hope we can look at my explanation as the simple one and yours the more complete one. I think we're saying pretty much the same thing.

The link you provided is really interesting. I'm not sure that diamagnetics would have a bearing at the technical level of our discussion, but it's interesting to say the least. Actually I don't agree with the statement in the article that you can't have levitation without diamagnetics. The only differences in permanent magnet and diamagnet levitation is that a diamagnet doesn't require lateral stabilization. A diamagnets flux lines are parralel with neither north or south poles of a permanent magnet.

Scenario: Make two balls of postage stamp shaped magnets.One 12" in diameter, the other 12 1/4" diameter. North and south poles perpindicular to the front and back of the magnets. Think of a disco ball. The first (largest) ball has all the north poles facing inward. The second ball has all the of the north poles facing outward. Put the smaller ball inside the larger ball and the smaller ball will be levitated. At least within the confines of the larger ball.

Anyone buy that for two cents? :) :)

Anybody else that wants to jump in here, please feel free to do so. Just try to remember that it is purely discussion. Not to be interpreted as dissension(sp?). Techno-geeks( I say that in a nice way) love this sort of discussion. Sometimes one even learns something. :) :)

Originally posted by throbbinnut
I'm still pondering the "exactly how does a pickup work" question. My best explanation right now has to do with the fact that a voltage is induced in a coil of wire when it is subjected to a changing magnetic field. As the string vibrates, it makes the amount of magnetic flux increase and decrease, which produces a voltage in the coil proportional to, and with the same frequencies as, the vibrating string.



Dingdingdingdingding!!! We ahve a winner!! That is absolutly correct!! Johnny, tell him what he's won!!

Huhn, wha? Showy, I wash up late lasht night *hic!*

:D

Rock on
Eric

Originally posted by MegaAngus


mayfairmistress...John is correct. And thats the most succinct defintion there is. You can tell hes correct with the magnetic field...here, try this: Put a nylon string on your bass, in place of maybe the G string. You can find one of suffiecient guage. Then play it. Do you hear it coming through the amp? Nope. Its non-ferrous, which means it wont be picked up or detected in a magnetic field, because its a non-metal mixture. Metals are made ferrous by combining two or more metals, and depending on the conbination of metals, the mixture will be more or less magnetic. In the case of strings, they are not magnetic enough to stick to a magnet, because then theyd just stick to the bridge and the frets. See?

[Edited by MegaAngus on 08-27-2000 at 12:37 PM]
Not to rag on you or anything MegaAng, but the definition of "ferrous" is a metal or alloy that contains Iron. you couldn't take pure nickel or lead or gold or any other elemental metal and make it ferrous without specifically adding iron.

That had already been stated though. So iron, and metals. Whatever, i knew that you had to have iron though. You knew what i meant, AND it had been stated. Nobody pays attention to my posts anyway. :)

Not about the pickup, but.....

Since the pickup only picks up the magnetic vibrations of the string, what is the "mission" of the wood (and other parts of the bass too)? Does different kinds of woods make the strings vibrate in different ways?

hey guys i jsut joined to put in my two cents on this whole pick up thing. from what i understand, pick ups are magnets coiled in wire. what happens is, the string vibrates, which vibrates the wood, which vibrates the magnet. when a magnet and a wire vibrate it creates an electrical sound, which is the sound being heard through your amp. as for your whole microphonic pick up theory, those pick ups are only boosted in picking up outside noises. try lowering your pick up or highering your strings. it won't be as loud. well because the strings are higher or the pick up is lower, does it make the wood vibrate any less? i dont think so. so the pick up is a microphone, and the microphonic pick ups are just boosted in thier abililty to pick up outside noises. now with the screaming into a pick up, sure the pick up picks it up but it'll be barely audible to the point where you cant hear it. try busting out a high gain pedal or turning the amp really high. with the gain amplifying the sound or the amp being louder, you'll be able to hear yourself scream through the pick up.

threadomancy!

Dear GOD this thread is old!