Horrible noises from Pickup/Circuit… Help!!

Discussion in 'Pickups & Electronics [BG]' started by elTopo, Nov 4, 2013.


  1. elTopo

    elTopo

    Joined:
    Nov 4, 2013
    Location:
    London, UK
    Hi, I've just got an Aria Pro II CSB 300 bass. Beautiful, sweet neck, extremely comfy and lovely tone. It seems to have been sleeping for quite a few years, but it's in pretty good nick for a 30 year old bass.

    Only problem is, whenever i strum or pull (hard) two notes simultaneously, the bass produces an awful noise, kind of like a distortion, but not a distorted bass sound, just the distortion without the bass sound. Yeah, the sound of the bass disappears for a moment and I get this loud crackly noise, similar to a jack plugging with the gain high but a bit higher in frequency. Sometimes I also experience pops and glitches on single low notes, especially when I hit the string with the nail (I play flamenco guitar as well, so, I have some nails.

    Tried different leads, amps, etc, and it's all the same, which leads me to think that there's something wrong either with the pickup or the wiring. I paid really little money for the bass, so I don't mind to spend up to 100 bucks or a bit more to get it in shape.

    I have an mp3 to show the sound, but I don't know how to post it!

    I'd appreciate any feedback/advice as to what's going on, since I don't know much about pickups and electronics.

    Also, in case I have to change the pickup (I hope not), any ideas of replacements for this model?

    Thank you!
     
  2. Technotitclan

    Technotitclan Lurking TB from work

    Joined:
    Mar 1, 2012
    Location:
    Rochester, NY
    Is it active? This sounds like a dying 9v battery. Check if it needs a battery. If it does than its dead.
     
  3. elTopo

    elTopo

    Joined:
    Nov 4, 2013
    Location:
    London, UK
    Hey, thanks for replying!

    No, it's not active. The bass is from 1983 and it has only one passive dual coil pickup.

    The thing is, when it doesn't pop or distort, the sound from the pick up is clean and quite nice.

    Actually, just listening to it, the bass sound doesn't disappear.

    https://soundcloud.com/eltopo-3/bass-noises
     
  4. Crater

    Crater

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    Oct 12, 2011
    Location:
    Dallas, TX
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  6. elTopo

    elTopo

    Joined:
    Nov 4, 2013
    Location:
    London, UK

    Hey, thanks!

    I've inspected the jack input as well as the knobs and cables inside. The Jack input is actually surprisingly tight and shiny. No rust whatsoever, maybe it was changed at some stage, but yeah, it's kind of perfect. I did still sand it a bit, but no change. Knobs also look fine, the few cables seem tightly soldered and make no noise when moved around (bass plugged).

    I guess that leaves the pickup or the main lead from it as candidates. When I play through my interface (Mbox 2) it shows the peak light when it does the noises, but it's not the usual peak cracky sound, it really sounds like something is really wrong somewhere. You can have a listen:

    https://soundcloud.com/eltopo-3/bass-noises

    I also took the pickup out, but it's glued to the housing, so I didn't venture to separate it and didn't see the actual coils, but, interestingly, the housing doesn't have a hole for the cable to get out, so, one of the sides pushes it against the wood!!! I found that extremely odd. The cable is deformed where the housing was pushing it, so it may be partially broken?

    Other than that, it has to be the pickup itself, but it's funny that it sounds perfectly fine until I apply heavy strum/pull.

    Thanks again!
     
  7. SirMjac28

    SirMjac28 Patiently Waiting For The Next British Invasion Gold Supporting Member

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    Location:
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    Man that sounds horrible great tone when she's quiet is it grounded properly?
     
  8. elTopo

    elTopo

    Joined:
    Nov 4, 2013
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    London, UK
    Yes it is, but as I say, I really don't mind to spend some money on it, even to change the pickup, but I actually like the sound, so I'd like to know what could be and if it can be fixed.

    In the knobs compartment there's a cable that comes from somewhere other than the pick up straight to the tone knob. I guess that's the ground, yeah?

    Thanks for replying!
     
  9. SirMjac28

    SirMjac28 Patiently Waiting For The Next British Invasion Gold Supporting Member

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    Aug 25, 2010
    Location:
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    Are there any wires leading to the bridge?
     
  10. jcanderson

    jcanderson

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    Apr 13, 2013
    Location:
    Los Altos, CA
    If it's an intermittent connection, try tapping around the bass body (and on the bridge, pickup, controls, etc.) with something hard but non-metallic, such as the handle of a screwdriver, and see if you can reproduce the noise that way.

    Also -- do you rest your thumb on the pickup while you're playing? If so, any correlation of thumb placement with the noise?
     
  11. jcanderson

    jcanderson

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    Apr 13, 2013
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    I forgot to ask -- is the bass active or passive? If active, there's a good chance something is being driven into clipping.

    Also, what happens if you adjust the controls (e.g tone and volume). Still the same distortion when striking the strings with the same force?

    If you lower the pickup height, does anything change?

    Also, don't forget to consider that the problem might be downstream from the bass -- perhaps other electronics are being overdriven?
     
  12. Crater

    Crater

    Joined:
    Oct 12, 2011
    Location:
    Dallas, TX
    I always suspect the "moving parts" or mechanical bits in the signal path: the output jack, the POTS, and the pickup switch if the instrument has one. Try "exercising" the volume and tone controls by rotating them through their full rotation several times and see if that helps.
     
  13. elTopo

    elTopo

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    Nov 4, 2013
    Location:
    London, UK
    Hey, thanks for replying!

    I do sometimes rest my thumb on the pickup, but not always, in facto, less than half of the time. I play flamenco guitar and I use some funny techniques for the bass, and also play quite a bit with my thumb. Anyway, no, no changes resting the thumb or not.

    I did tap it and, YEAH! it does make a noise similar to the noise from strumming, quieter of course, but I think it's the same thing. it does more on the bottom half of the body that on the top, and the most response is around the knobs and, strangely on the top "horn" (the body is something like a PRS guitar with SG horns).

    That's probably good though, it must be something minor I suppose. Well, at the end of the day, it's either the pickup or the circuits/ground, there's nothing else that can cause such a noise. Good thing that it's a really simple bass, 1 pickup, 2 knobs, tone and volume.
     
  14. elTopo

    elTopo

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    Nov 4, 2013
    Location:
    London, UK
    Yes, there's a wire from the tone control to the bottom of the bridge. I took the bridge out and put it back, it really seems fine, there's a thin piece of plastic underneath the bridge to make sure the wire stays touching it. Funny enough, I was looking for this grounding issue, and, while playing through my laptop/interface I was hearing this massive ground noise. I thought that was the problem, but just now I realised that if I touch the laptop (aluminium) the noise disappears, and also if I put it to charge. That's a bit annoying though, it basically means that you can't record on battery power, without a ground noise!? Grounded or not, however, it still produces the noise you've heard!

    Anyway, ground seems fine, the cable is definitely tight against the bottom of the bridge and well soldered to the tone knob. I moved a bit around and it didn't make any sounds.
     
  15. jcanderson

    jcanderson

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    Apr 13, 2013
    Location:
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    Ok -- if you can reproduce the noise by tapping, that implies that the problem is probably an intermittent connection. But there's a caveat -- tapping the body also causes the strings to vibrate, which will induce a signal in the pickup, and if the problem is actually elsewhere (e.g. clipping), what you think might be a problem caused by an intermittent is actually something completely different.

    So two points, one general and one specific: always question your assumptions when troubleshooting, and try to mute the strings (with palm, or towel, or...) when tapping around the instrument.

    If tapping on the pickup itself does NOT cause the noise, then the problem probably isn't there. There's not much left -- I'd pop off the back cover over the controls and start tapping on each wire and component. Use something small, but stiff and non-conductive (back of a BIC pen, etc.).

    Tap on your cable plug, too, and also wiggle it, just to make sure the problem isn't there (and have you tried a different cable, too?).

    Also -- is the sound of the noise affected by the setting of the tone control? (test at full clockwise and full counterclockwise).

    (Another test for intermittents: If you shake the guitar vigorously, do you get the noise?)
     
  16. uOpt

    uOpt Supporting Member

    Joined:
    Jul 21, 2008
    Location:
    Boston, MA, USA
    Need to disconnect and try pure pickup with crocodile clips, then work your way forward.

    To me it sounds like a almost-broken wire or solder connection, or a fried pot. But speculation is useless, measuring rocks.
     

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