Question for the REAL experts:59N vs. JazzN

[BachToRock]

Re: Question for the REAL experts:59N vs. JazzN

INDUCTANCE - (physics) a property of an electric circuit by which an electromotive force is induced in it by a variation of current

ELECTRONICS 101...

INDUCTANCE:
Inductance is typified by the behavior of a coil of wire in resisting any change of electric current through the coil.
Arising from Faraday's law, the inductance L may be defined in terms of the emf generated to oppose a given change in current:

FARADAY'S LAW:
Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. No matter how the change is produced, the voltage will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc.

For a pickup(fixed area and changing current), the factors NUMBER OF TURNS, MAGNETIC PERMEABILITY and AREA OF COIL are applied to Faraday's law.

Inductance in a pickup is not a factor of the core itself... it is of the coil within the magnetic field as the laws of Physics define.
The coil produces voltage (ie SOUND) when the magnetic field is induced by the vibration of a strings... size and shape of the coil help determine the frequency response of the pickup... if the coil is fatter and further away from the core then it is in a weaker area of the magnetic field which will affect the response

Once again... I stress... there are MANY factors detemining the final outcome besides the size and shape of the coil... WIRE GUAGE, RESISTANCE, CAPACITANCE, INSULATION TYPE, WINDING PATTERN, MAGNET TYPE, SIZE & SHAPE OF MAGNET, ETC...

 

[sanrafael]

Re: Question for the REAL experts:59N vs. JazzN

So I'm reading this as DC Resistance measurements aren't good indicators of overall output....am I right??

Well, it is about the best single indication there is. But it is just an indication. And Lew has a very good ear and wants to know exactly what is going on. More power to him!

 

[BachToRock]

Re: Question for the REAL experts:59N vs. JazzN

Yeah man... LEW has a great ear in my eyes because we like the same pickups!

 

[sanrafael]

Re: Question for the REAL experts:59N vs. JazzN

. if the coil is fatter and further away from the core then it is in a weaker area of the magnetic field which will affect the response

If you are going to quote Faraday's law, you need to understand it better. The induced voltage depends upon the sum of the product of all the little areas inside the loop of wire times the changing magnetic field at that little area. (You can state that better as an integral, but let us forget the math for now.)
The fact that the field is weaker further from the coil is not what counts, it is the whole field inside that counts.

 

[Kent S.]

Re: Question for the REAL experts:59N vs. JazzN

The fact that the field is weaker further from the coil is not what counts, it is the whole field inside that counts.

That was my basic understanding of it ... I'm not sure as to the effect of the magnetic field itself on the coil ... alnico magnets do alter the coil inductance a bit, enhancing the core if you will, however ceramics do not. The effect to a magnetic field ... hmm, don't know ... now changing the shape and spacing of a coil certainly has an affect on it's capacitance; which of course combined with the inductance creates the resonant peak and tunes the pup. Interestingly though inductance can be changed by various amounts of current induced into the coil (the voltage being a product of the the DCR and L and C reactance contributing to the further tonal shaping of, via more or less voltage according to frequency), but the current is so small that I couldn't imagine it having any affect on the inductance. Capacitance, that I could see. Considering though that a pup has properties of both an air core and a ferrous core inductor (the space of the bobbin itself that is, as opposed to the slugs and screws, or baseplate), I wonder what that does to the whole shebang. I'm waiting for the concrete answer concerning the coil's inductance on this one.

 

[Kent S.]

Re: Question for the REAL experts:59N vs. JazzN

Oh yeah, my vote was the change in capacitance due to the insulation and or wire gauge ... :13:

 

[Lewguitar]

Re: Question for the REAL experts:59N vs. JazzN

Thanks Kent! I very much appreciate your input too. Feel like I've been going to Guitar Pickup School the last few days with the Clapton thread and now this one. Thanks again to everyone who has participated. Hat's off to all of you! Lew

 

[Kent S.]

Re: Question for the REAL experts:59N vs. JazzN

Thanks Kent! I very much appreciate your input too. Feel like I've been going to Guitar Pickup School the last few days with the Clapton thread and now this one. Thanks again to everyone who has participated. Hat's off to all of you! Lew

I'm not saying that the inductance doesn't change, it may infact (I don't quite understand why as on one hand I can see how it could, but on the other not). As a curious point though ... The magnet does affect the harmonics and dynamics of the string itself, so that right there will affect everything else.
Anyway, a lot of people talk about the strings inducing voltage in the coil ...NOT! It doesn't work that way, those strings cutting thru the lines of magnetic flux induces a *current* in the coil (not a voltage), the voltage is a product of the current's interaction with the resistance (in this case impedance of the coil) ... this is why the resonant peak Fc is where the resistance is highest, not lowest. If you envision a voltage applied to the coil it's easy to think that the highest point of resistance (well impedance, you know what I mean) would produce a lower voltage. Know once that's gets going then the inductnce of the coil starts to play a much larger part in the voltage, every single thing is in a constant and ever changing state of flux (no pun intended) ... it just gets to weird to even think about. The interesting thing is what determines the amount of current inducing in the coil in the first place, even though it's very small. It would appear that the coil not only produces a signal in a non-linear form (some frequencies luder than others per what it pickups up, but then it also acts as a filter to further shape the frequency response (or more correctly transfer characteristics).
Man, it's just to much to think about ... :headache:

 

[Marcel]

Re: Question for the REAL experts:59N vs. JazzN

They are wound with "similar" wire, but the 59 uses a heavier/thicker insulation which forms a fatter coil.
This creates higher inductance which translates to a bassier and less clear sounding pickup.

High inductance is a major part of the P-90's sound... they have a short/fat coil and tone that matches!

Otherwise... the Screws, Slugs, Magnet and baseplate are the same... the wood spacer could possibly account for some microphonic vibration absorbtion/suppression in comparison to a plastic one?

Of course there are MANY variables in what creates the sound that comes from our instruments and eventually out of a speaker... here is a great article for those with the minds to comprehend...
http://www.buildyourguitar.com/resources/lemme/

ah i've already read the german version of this article. It's good. But he simplify everything imo. There are much more effects in a pickup. I just think of magnetic hysteresis etc,.... but i have to first think more about this