What is this problem with my jazz??

Discussion in 'Basses [BG]' started by bobbykokinos, Oct 24, 2005.

  1. Recently my jazz bass has been having a weird issue where it sounds like it has self chorus.. My guitarest was listening and he asked if I had chorus on my amp and I dont. It seems like its mainly obvious after the 12 fret but sometimes lower.

    Is this just a bad setup or is there something else wrong??
  2. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Got a sample to listen to? That's a tough one to call on what you're saying. Try listening to various parts of your bass and see if you can isolate something wrong.
  3. cheezewiz


    Mar 27, 2002
    Having the pickups too high will often result in a chorus like effect.
  4. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Wow, that's freaky! I have to say that's the first time I ever heard something like that from a bass! You're getting two distinct notes that get more and more out of tune with each other as you go up the neck. I wonder if your intonation is way off. Short of that, I have no idea what's causing it. But it's possibly the most freaky problem I've ever heard. Watch there be a really simple answer for it, too.
  5. Yeah, I've never experienced it either. My intonation at the 12th (harmonic and fingered) is on..
  6. BassyBill

    BassyBill The smooth moderator... Staff Member Gold Supporting Member

    Mar 12, 2005
    West Midlands UK
    This may be right, I'd try this first. Next suspect would be the strings if they're an old set.
  7. take your string off the tuning peg and restring it and make sure that there are enough wraps to properly seat your string in the nut (you know...downward pressure).

    If its still there...raise your action a hair and see what that does...also, make sure that both screws from your bridge saddle (for that string) are properly touching the plate.

    it could also be a wonky string...but, these are simple first checks...

    but yes, that is FREAKY!
  8. BassFelt


    Mar 26, 2002
    Your pickups are too high, which causes so-called string pull. The magnets pull on the strings and cause so-called "wolf-tones".

    See if it is possible to lower the pickups. If not, you'd have to raise the saddles, and if that brings the action too high, the neck angle should be adjusted with shims to get back to the same action.
  9. Visually, the pickups dont look unusually high but I could be wrong.. I can't lower them much because there is a piece of foam under the pickups.. Is it safe to just take the foam out?? Is it really needed??

    Now just curious, but if it is a pickup problem, isnt it more likely to be isolated to one pickup than both?
  10. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I don't think it's pickups myself. The string is producing two very distinct notes, a fundamental and a note that gets flatter as you go up the neck. I don't see how the pickup could be involved.
  11. I frankly dont think its the pickups either. Actually, I know for a fact its not pickups. I'm dumb and didn't try it without it being plugged it.. The chorus effect is still audible without being amplified.
  12. Brad Johnson

    Brad Johnson Commercial User

    Mar 8, 2000
    Gaithersburg, Md
    Boom Bass Cabinets, DR strings
    Does it still occur with each pickup soloed?
  13. It occurs all the time. Amplified or not. So it isnt the pickups.
  14. BassyBill

    BassyBill The smooth moderator... Staff Member Gold Supporting Member

    Mar 12, 2005
    West Midlands UK
    The pickups can cause still wolf tones unplugged as they still have a magnetic effect because... er... they've got magnets in ;). The normal thing to try is lowering the pickups. The foam should compress down enough to let you do this, that's what it's for. I don't believe this is an intonation issue, and if the problem were the way the strings were fitted you'd probably notice it more on lower notes/open strings. Lowering the pups slightly woul be the first thing I'd try - easy to do and easily reversible if it's not the answer. Next suspect would be, as I said, a bad string.
  15. Pennydreadful

    Pennydreadful Goin out West

    Jun 13, 2005
    Arlington, Texas
    I thought this was the strangest thing I'd ever heard until, honest to god, it happened to me about three minutes ago. I was fiddling around with my EQ, and suddenly...chorus? What the crap, I thought.

    It happened when I had all my EQ settings cranked all the way up. I think that combined to how hot my single coils are just kinda overloaded everything, and gave it a chorus/octave kind of effect. Strange.

    But if your bass does this unplugged, as you say, I guess I can't really help, although lowering the pups still sounds like a good idea to me.
  16. I noticed a similar phenomenon on fretless bass. If I tap and hold down the string near the 12th fret position and rock my finger I can hear both sides of the string speak and they oscillate against each other much in the way your bass is. Also remember when intonating, not only do it with brand new strings but also check the other notes, not just the 12th fret. With recent setups I've done on basses I've noticed that if I only intonate it at the 12th fret many of the other notes are out. If I adjust it so that the most amount of notes possible are in tune, the 12th fret is usually out. Weird. So just a suggestion. Try muting the non-playing side of the string and/or any other strings that might sympathetically vibrate. Good luck!
  17. A question for you.
    Do you happen to have a bad a** bridge on the bass? I have heard that happen when the saddles were not cut right. Is it only happening on one string?
  18. pointbass

    pointbass Semi-Retired Gold Supporting Member Supporting Member

    Nov 4, 2004
    Acworth, GA
    Endorsing Artist: FBB Bass Works
    My vote would also be to a string problem. Do you have enough wraps on the tuner? I recently worked on a bass that only had ~ 1 wrap and I couldn't get it in tune past the 5th fret, plus it was producing some weird harmonics.......
  19. pedroferreira


    Feb 10, 2003
    I would change the strings first.
    Buy a new set of strings from a different brand and see if that effect is still there.

    Anyway: what strings are you using?

    Good Luck,