1. The Rules have been updated regarding posting as a business on TGP. Thread with details here: Thread Here
    Dismiss Notice

Magnetic pull from pickups? What have YOU experienced tonewise?

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by dukeh62, Feb 18, 2009.

  1. dukeh62

    dukeh62 Supporting Member

    Messages:
    2,210
    Joined:
    Sep 1, 2004
    Location:
    CT
    Hey guys,

    We always read about how having your pickups too close to the strings can cause decreased sustain, fret buzz, loss of tone, etc.

    Have any of you actually experienced this, and if so, HOW DRASTIC was the improvement when you lowered the pickup(s). I'm concerned with the effects on sustain and tone of the string itself, as opposed to "more treble, bass, etc."

    I've got A5 magnets in my tele..and the bridge pup is really close to the strings. Wondering if that is taking some sustain away. I'm going to experiment tonight, but the guitar is at home right now. Just wanted to get some insight.

    Thanks!
     
  2. tim boehlert

    tim boehlert Member

    Messages:
    488
    Joined:
    Jul 16, 2007
    Read my review and then run out and get this book - really! It has all the information you're looking for, and may help you out without wasting a lot of time experimenting.
     
  3. Pat Healy

    Pat Healy Member

    Messages:
    10,959
    Joined:
    Jul 22, 2007
    Location:
    Denver, CO
    It's called stratitis, and it can have very dramatic and negative effects. The stock pickups in my Tom Anderson had oversized pole pieces that exerted a very powerful pull on the strings. This caused a really awful warbling noise when I'd fret notes above the 12th fret. Backing the pickups down flush with the pickguard helped slightly, but it was still intolerable. Swapped 'em out for Seymour Duncans with normal pole pieces, and the problem disappeared immediately.
     
  4. diego

    diego Member

    Messages:
    2,562
    Joined:
    Jun 16, 2006
    Location:
    San Francisco
    I had enough string pull from the bridge pup on my Suhr Classic T that I thought I needed to add relief to the neck.

    I also had string pull from a Duncan Lipstick tube that created a loss of sustain on particular notes.

    In my experience I hear loss of sustain and kind of a choked tone as a result of having pickups too close.
     
  5. dukeh62

    dukeh62 Supporting Member

    Messages:
    2,210
    Joined:
    Sep 1, 2004
    Location:
    CT
    Thanks Diego.
     
  6. diego

    diego Member

    Messages:
    2,562
    Joined:
    Jun 16, 2006
    Location:
    San Francisco
    You are welcome. Probably a good idea to play every note on every string to really find out what's going on...
     
  7. dukeh62

    dukeh62 Supporting Member

    Messages:
    2,210
    Joined:
    Sep 1, 2004
    Location:
    CT
    When you say "choked tone" do you mean from the string itself when play acoustically? That's what I'm trying to address. It's like feeling like the guitar has 9's on it, when it really has 11s.
     
  8. uOpt

    uOpt Member

    Messages:
    897
    Joined:
    Jan 16, 2008
    Location:
    Boston, MA, USA
    I my opinion, string pull is a myth.

    The distortions that you hear when you get closer to the strings, in particular with rod-magnet pickups like Fender single coils, is the result of the different view that the magnetic fields gets from the swinging strings. I should really make a diagram, but basically if you are very close then a perfect sinus swing of the string that goes vertically will induce a non-sinus wave because the close pickup sees the "downswing" much stronger than the string's turn away from the pickup. This changes every sinus shaped overtone into a slight sawtooth shaped current - which is the nonlinear distortion that you hear.

    Magnetic pull might or might not come on top. My guess it doesn't play a big role.

    The only way to really tell is to record the thing with a microphone with pickups at different distances. Then you know whether the sustain is actually shorter or whether it's just a result of the shift to treble which naturally sound shorter (high overtones decay faster).
     
  9. walterw

    walterw Gold Supporting Member

    Messages:
    33,258
    Joined:
    Oct 16, 2006
    ??

    the problem with excess pull is not just an unwanted tonal change in the string, but that the pull actually makes the higher partials out of tune with the fundamental, showing up as a "warbling" sound and a string that won't tune or intonate properly.

    put a set of EMGs in a strat, and that neck pickup can be raised up to the point it begins to slap into the string with no ill effect. even a vintage-syle rod-magnet pickup with alnico II mags will have far less of the problem than alnico V pickups do at the same distance.

    it's all about the pull.
     
  10. Pat Healy

    Pat Healy Member

    Messages:
    10,959
    Joined:
    Jul 22, 2007
    Location:
    Denver, CO
    Based on personal experience (above), I disagree with this.
     
  11. markj

    markj Member

    Messages:
    46
    Joined:
    Oct 2, 2007
    My stock MIA 2003 had terrible stratitus above the 12th fret on the E and A strings. I put some CS 69's and I could get them a LOT closer without that problem. The stock pups obviously have some more pull to them. It was even more noticable when I put some dirt on the channel.
     
  12. JPF

    JPF Member

    Messages:
    8,598
    Joined:
    Jan 4, 2002
    Location:
    New England
    I agree completely - the only guitar I keep with minimal distance between pickups and strings is my EMG DG-20-powered Stratocaster.
    All of my other, passive pickup-powered guitars are tweaked with considerably more string height, and it's amazing to see how much the tone is affected by small incremental adjustments.

    My copy of Dave Hunter's new book which Tim references arrived yesterday, and I plan on reading it this weekend, and will probably tweak my guitars some more well into the night...
     
  13. Boris Bubbanov

    Boris Bubbanov Member

    Messages:
    19,456
    Joined:
    Apr 30, 2008
    Location:
    New Orleans + in the past
    Try this little experiment. Keep adjusting the pickups higher. And higher. And higher.

    You should start hearing wolf tones, notes ringing out false, the whole plethora of (what was it?) 'myriad inexplicable phenomena'. Sumpin' lie kat.

    I notice as I am playing in a new homebrew, that as I go from just one pickup, hotwired directly to the jack, and then on to more and more magnets dials and switches present on the guitar, that while the guitar gets more user friendly/housebroken in terms of what these guitars are constructed for ( entertaining people), that I lose a slight spark that a single pickup guitar offers.

    I call it magnetic drag.
     
  14. Bob V

    Bob V Member

    Messages:
    1,191
    Joined:
    Dec 31, 2007
    Location:
    Glen Head, New York
    Whether the effect is coming from magnetic pull is academic. The fact is that there is a dramatic difference in sound once you get past the sweet spot or window of adjustment on pickup height. Pickups just plain misbehave when they're too high (you just don't want that "myriad" thing going on). Pickup height adjustment screws are in the range of 32 or 40 threads per inch, so a full revolution of the height screw is a good unit to try adjusting. Try two turns at a time until you're in the range you like, then tweak it with a full turn up or down until you're happy.
     
  15. Keyser Soze

    Keyser Soze Member

    Messages:
    1,477
    Joined:
    Dec 14, 2008
    Location:
    Johnson city, TN
    That's a distinction without a difference. There is no way to isolate one effect of pickup height (be it signal amplitude or treble/bass mix) from all the rest.

    Ultimately the only thing I care about is the audible (amplified) difference in overall tone (including sustain.) My own approach is rather simple - start with the pickups flush to the guard, tweak the height adjustment screws by a quarter turn until it ceases to sound better or until wolf tones appear. Either way, you back off one quarter turn, back to what sounded best. That is as good as those specific pickups will get.

    Assuming I don't change anything else...
     
  16. Tone_Terrific

    Tone_Terrific Member

    Messages:
    24,838
    Joined:
    Dec 26, 2004
    Location:
    Canada-GTA

    Very interesting and would explain how I can hear distortion from pups (esp a certain bridge hb that was too close) and did not know how it could originate.

    Note that if you move a pup so close that the mag field is interfering with the motion of the string the effect should be noticeable from any pup, not just the close one. Is that happening for everyone?
     
  17. DC1

    DC1 Member

    Messages:
    14,556
    Joined:
    Oct 30, 2006
    Location:
    SoCal

    Something strange with this story. Tom's PU's have some of the lowest string pull of any out there. I confirmed this with him myself, saying it was one of his tone secrets and he agreed.

    From his site:

    All our Anderson-style single coil pickups have a smooth, full, richness without sacrificing that all important single coil clarity. These pickups also utilize a uniform magnetic field to eliminate high and low string dropouts and excessive string pull.


    In fact, I have used Anderson guitars and PU's for 20+ years and in my experience they have the lowest string pull available compared to other well known PU's.

    String pull, and dealing with it effectively is an important issue in getting a good sound.

    dc
     
  18. Keyser Soze

    Keyser Soze Member

    Messages:
    1,477
    Joined:
    Dec 14, 2008
    Location:
    Johnson city, TN
    Not necessarily. Each pickup is exerting its magnetic forces over a limited area of the strings while the entire rest of the strings' motion is attempting to resist that force. Likewise each pickup is only 'seeing' a similarly limited portion of the strings, and that portion may be displaying it own unique waveforms.

    The effects are going to be somewhat localized - yes a portion of the effect does get transmitted through the entire string, but that does not mean it is necessary detectable over the entire length of the string. Also remember that any given pickup's frequency response is location dependent.

    There are any number of conceivable outcomes. Overtones might be more noticeable where they happen to be (relatively) in phase with the string's vibration creating an added unpleasant sound. In other locations on the string these same overtones could be out of phase and possibly less noticeable (sometimes you don't notice what is missing.) Or you may have a situation where nasty high frequency overtones are present but are relatively low amplitude and are drown out by other lower frequencies of higher amplitude (Basically a signal to noise phenomenon.)

    In my, albeit limited, experience (this is not something I've willfully tried to reproduce) wolf tones are most noticeable (and unpleasant) on the bridge pickup. I would agree that when they are present on the bridge pickup there probably is something going on on the neck pickup, but whether it will always be audible I'm not so sure.
     
  19. Tone_Terrific

    Tone_Terrific Member

    Messages:
    24,838
    Joined:
    Dec 26, 2004
    Location:
    Canada-GTA
    Conventional wisdom, (fwiw), indicates bridge pups should be less likely to cause string problems due to the lesser excursion of the strings and the added rigidity of the string near the bridge. :huh I'll be careful about spacing, either way.

    I have had something that sounds like distortion from pups but sure don't know why.
     
  20. jdogjent

    jdogjent Member

    Messages:
    78
    Joined:
    Jun 15, 2007
    if the earth stopped rotatings magnets wouldnt works
     

Share This Page