I keep reading that J pups are the same.

Discussion in 'Pickups & Electronics [BG]' started by KayXero, Dec 28, 2013.

  1. KayXero


    Apr 3, 2007
    I keep reading this about J pups. And it makes sense to me, to a point, and then I get confused. Ive read numerous thread with people basically saying the pups arent really different, but then a few guys will sometimes say they are a decent bit different.

    Ok, so generally a set of J pups is wound the same number of times, but because the bridge pup is a little longer, it will have a higher K rating (ex: DCR 7.0K neck vs 7.5K bridge). And then because strings vibrate less at the bridge, this compensates for that difference in output and tone. Am I correct so far?

    But the difference in K rating I see on some sets, is a little different than what I see on other sets. Either way, with all this said, would putting a bridge in the neck or a neck in the bridge produce different tones? Or are the pups pretty similar and is it their position under the vibrating strings that really provides the difference in tone?

    And then on top of all this, certain basses seem to have the same pup (at least length wise) in the bridge and neck position.
  2. Mystic Michael

    Mystic Michael Hip No Ties

    Apr 1, 2004
    New York, NY
    Assuming that you define "J pup" as a direct Fender Jazz copy (and it's hard to know exactly what you mean by that term until you actually state your definition), including single-coil wiring, I would characterize the differences between one make/model and another as "variations on a theme". That means there's an inherent similarity in tone & timbre that exists among all of them, despite their relatively subtle variations.

    If you define "J pup" as all pickups that have a similar form factor to the Fender Jazz, then that obviously increases the variability factor a great deal, relative to tone, timbre & performance. By "K rating", do you mean "impedance"? :meh:

    Generally, pickups are in fact engineered to function optimally in their respective positions, i.e. bridge pickup in the bridge location; neck pickup in the neck location - and not just J-style pickups, but most pickups. So they're not necessarily built with the same number of turns - or even with the same type of wire - even within a given set of the same make & model. It just depends upon the particular manufacturer.

  3. KayXero


    Apr 3, 2007
    J pup = Fender Jazz pickup or a copy of such a pickup. And K rating = impedance.

    Sorry for my non-technical terms lol

    Thanks for the useful info btw.
  4. ReidK

    ReidK Jst sy n t lsy cmprsn.

    Well, if we're going to get picky about terminology, it isn't impedance either, it's DC resistance. Impedance is the sum of the resistance and the reactance, which in a pickup is inductive.

    And as long as we're on the subject, the DC resistance number doesn't really describe the output of the pickup. You can easily make two pickups that have the same DC resistance but vastly different output levels, or vice versa, by using different gauges of wire and/or different types of magnets. Using the resistance to compare pickups is really not a great idea, it's just easy to measure, and most of the time it gives a (very rough) approximation of the truth.

  5. BlueTalon

    BlueTalon Happy Cynic

    Mar 20, 2011
    Spokane, Washington
    Endorsing Artist: Turnstyle Switch
    Fender itself makes many different flavors of Jazz pickups, including hot/modern & vintage single coils, and stacked & split-coil humbuckers, and other manufacturers produce a much wider variety of pickups than that.

    It makes no sense at all to me why anybody would claim or imply that J pickups from Fender and other manufacturers are basically the same, but I'm pretty sure it's the minority opinion. You might have read numerous threads in which somebody gave that opinion, but I'm sure it was substantially more than "a few guys who sometimes say" they are different.

    If you specify that you are only referring only to vintage-style medium-output single-coil pickups, then yeah, someone could make the case that J pickups from Fender and from other manufacturers are basically the same. But the fact that you'd have to make that specification before making that claim should be all the evidence you need to conclude that the claim is just plain wrong.
  6. KayXero


    Apr 3, 2007
    ^You misunderstand what Im saying.

    I am not saying that people say all J pickups are the same. Im saying that some people say that 2 pickups within their own set (ex:MIA Jazz Neck vs MIA Jazz Bridge on the same bass) are almost the same, and that their position under the string vibration accounts for the difference in tone (and not necessarily the pickups specifications)
  7. kohntarkosz

    kohntarkosz Banned

    Oct 29, 2013
    Edinburgh - Scotland
    As you correctly assert, placement of pickups on a Jazz bass make up the majority of the character of said basses. The bridge pickup has less string vibration to induce into an electric current. This is the same principle as violinists playing sul ponticello; riding the bow right up near the bridge to get a trebly and thin sound.

    I presume it was Leo Fender who decided to wind the bridge pickups hotter to 'balance out' the tones of the two pickups. Given that the two pickups comb filter to some degree, resulting in a distinct mid-scooped tone, the ~.5 k ohm difference in pickups is probably fairly imperceptible.

    The general construction of all Jazz bass picjups is the same. However some manufacturers have used two side-by-side coils, wired out of phase, to cancel hum. These include the Dimarzio Area J, Model J, Ultra J, Bartolini 9J series, and Nordstrant NJ4SE/NJ4SV.

    This principle can be seen thus;

    Conventional J-pickup guts.


    Split coil J-pickup guts;


    You can further change the tone here by configuring each 'half coil' to be wired in series or parallel with its neighbor.

    To answer the question posed in the last post, the pickups in a set will be 95% the same. The bridge pickup will be wider (discounting those fitted to old MIM Jazz basses, Washburn T24s and no doubt other basses). This increase in width alone may account for the ~0.5 k ohm increase in DC resistance, or it might be a conscious decision on the part of the pickup winder. You really want to know the inductance of the pickup over the DC resistance to get a better understanding of the tone. Generally though, pickup sets are built to compliment each other. However, taking a Dimarzio Ultra J neck pickup, rated at 12.3 k ohm, and sticking it in the neck, and taking a Dimarzio Model J, rated at 6.8 k ohm and sticking it in the bridge, will probably still sound like a Jazz bass. I've mixed crazily different pickups (16 k bridge, 8 k neck), from a set of Wilkinson Hot humbuckers, and still found them to balance when they were both on.

    I think the obsession with DC resistance came from Dimarzio issuing the Superdistortion pickup and everybody wanting that nasal Boston 'cocked wah' guitar tone personally.