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How to significantly reduce the single coil noise?

Discussion in 'Pickups & Electronics [BG]' started by bramhc, Jun 25, 2014.

  1. bramhc

    bramhc Banned

    Jan 31, 2014
    I already make a decision to add a preamp to my MIM Jazz Bass. And it already shielded (nice job Fender). I could tell it's noiseless. But if I added a preamp, I think the noise will amplified too (not much, but of course it will).

    So, is there other ways to reduce the noise more further?

    (Sorry if my english isn't good enough). Cheers.
  2. Rickett Customs

    Rickett Customs

    Jul 30, 2007
    Southern Maryland
    Luthier: Rickett Customs...........www.rickettcustomguitars.com
    Shielding would be first (pickup cavities, bottom of pickguard, bottom of jack plate, control cavity). Is it paint of copper foil already? If you're decent with soldering/wiring, replace lengths of the pickup leads with shielded cable.
    How are the ground wires meeting ground? Any long ground runs? Is it "star grounded" (google it).

    No one thing will "greatly" reduce the noise, there are many outside factors that will always "come and visit" from time to time.........ie...noisy power (A/C), neon lights on the same circuit, older electrical circuits with ancient wiring, etc. To completely remove all noise from single coils has been the plight of every repairman/luthier for decades, lol.

    One "signifigant" solution is a "dummy" coil, although it does alter the sound a bit.
    Last edited: Jun 25, 2014
    bramhc likes this.
  3. rolleharris


    Nov 10, 2002
    Falun Sweden
    Or put EMGs in your bass. Problem solved :)
  4. bramhc

    bramhc Banned

    Jan 31, 2014
    My parents didn't fully support me. So I have to be wise about upgrading. Sorry :)
  5. bramhc

    bramhc Banned

    Jan 31, 2014
    Very informative. Thanks :D
  6. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    Had a small thing to add to Jason's post, above. Perhaps you already know about this!

    The usual J wiring has the pickups out of phase when they're evenly blended. In effect, they become a big humbucker when combined, and null out the 60 cycle hum.

    So you might try to identify exactly what noise you're most concerned about. If its radio or electromagnetic interference, look to improving the shielding because that junk gets in everywhere in the wiring. But if it's 60 cycle hum when you solo either of the pickups, AFAIK (and I'll defer to more knowledgeable folks on here!) that's baked in the cake with single coils in a J. You'd need to install hum-cancelling J p'ups to address that. I like the ones in my Sadowsky, but they don't sound exactly the same as single coils. Aguilar and Nordstrand also make hum-cancellers.

    Something that won't cost you a dime to address 60 cycle hum (again, not EMI or RFI) is to make it a habit to run equal volume from both pickups. If you can get the tone you like on the amp and cabinet with the bass set like that, you can see about pickup replacement later. And you can still cheat a bit louder on one pickup or the other, but they gotta be close in volume to kill the hum.

    Again, I'm not a tech--just a player--and I'll defer to the more knowledgeable TBers here.
  7. lz4005


    Oct 22, 2013
    J pickups are not wired out of phase. Out of phase pickups result in a tinny sound with no low end.
  8. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    I believe you're mistaken about that.


    Actually, the signature "scoop" of the J is because of this.
  9. lz4005


    Oct 22, 2013
    I am not mistaken.

    The scoop when both pickups are at full volume is the result of phase cancellation due to combining signals from two different points on the same string, but that is completely different from pickups being wired out of phase with each other.

    On 99% of Jazz basses one pickup is reverse wound and reverse polarity so that they hum cancel when combined, but they are wired in phase.

    This article describes phase and polarity correctly: http://www.seymourduncan.com/blog/the-tone-garage/pickup-polarity-and-phase-made-simple/

    Put more simply: Phase cancellation with two in-phase pickups results in less treble. Out of phase wiring results in less bass.
    bluesdogblues and bramhc like this.
  10. Dogghouse


    Jan 25, 2011
    Santa Barbara
    Bass Guy @ Seymour Duncan
    The dumby coil method we offer is a "Stacked" Jazz Bass single coil, Vintage (Classic) or Hot versions.
    True, some people think there is a slight roll off of top on them. There is a trick to make up for that by changing to a 300k or 500k which will bring back that top end nicely.
  11. This is correct.

    There is often confusion on the difference between phase differences as a result of electricity being induced at slightly different moments in time, and 180 degree inversions caused by flipping wiring and/or magnets the other way. Is is important to note that magnet and coil polarity inverts phase by exactly 180 degrees, while changing the placement of pickups relative to each other changes phase by small degrees.
  12. bassbenj


    Aug 11, 2009
    First you need to determine the CAUSE of the noise. There are several types of noise pickup. Electric pickup which is determined by noticing that it goes away or gets less when you touch ground (such as the strings). Shielding will stop this kind of noise. Then there is "single coil noise" which does NOT go away or get less when you touch ground but WILL change volume, even totally null out, if you find just the right ORIENTATION (may not be playable) of the bass. Only a humbucker will stop this noise. Note the two Jazz bass pickups when on at the same volume act as a humbucker and this noise is gone.

    Best bet with single coils is to put in as good a shielding as possible. My MIM Fender V came with reasonably effective paint shielding. But a small amount of hum was getting through. (note had a preamp and as you note sometimes preamps will pick up additional noise but still shielding stops it) So I did copper foil on EVERYTHING; and it stopped that hum cold! And of course single coil hum remained. And I"m afraid there was only one answer to that one. I replaced pickups with SCN hum-cancelling pickups. Hum now totally gone, but of course wallet is now somewhat lighter. Bass sounds terrific though.
    bramhc likes this.
  13. acebase62


    Jun 29, 2010
    I use (2) 500k volume pots and a Fender TBX tone control in a Warmoth JJ bass using SD Hot Stack pickups.

    This set up gives me plenty of clarity, and the same results with split coil JJ pickups.
  14. bramhc

    bramhc Banned

    Jan 31, 2014
    So hum-cancelling pups do the job very well to rid off the noise significantly. Thanks :)
  15. Ensure everything is properly grounded. In my experiences of customizing electronics the grounding has been the primary factor for hum.
  16. BlueTalon

    BlueTalon Happy Cynic

    Mar 20, 2011
    Spokane, Washington
    Endorsing Artist: Turnstyle Switch
    While a good idea, it isn't necessary if one goes to the trouble of shielding the wire channels. This is an uncommon step, and some people think it is a waste of time, but I do it. I'll use either copper foil or copper tubing, and solder it to the cavity shielding on both ends.
  17. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    Hey, I appreciate folks clarifying my understanding of how Js work!

    Had a puzzlement--and I'm _not being argumentative_, not at all. Just trying to get the concept.

    So if the J scoop (with both pups in equal amounts routed to the output jack) is attributable solely to differences in the harmonics' phase read at two different positions, why isn't this scoop apparent on basses with two soapbars blended equally? The same physics would apply, I would think.
  18. lz4005


    Oct 22, 2013
    That has to do with pickup aperture. Basically, J pickups are "hearing" a very narrow part of the string. Humbuckers/soapbars are picking up harmonic content from a much wider section of the string. There is still phase cancellation going on, it just sounds different because there's a wider range of harmonics being combined.

    It's the same reason small differences in pickup location are more noticeable with J pickups than with humbuckers. Wider pickups are essentially averaging the sound from a larger chunk of the string, while single coils are focused on a very specific location.

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