Silencing Single Coils (And Other Jazz Bass Stories)

Discussion in 'Hardware, Setup & Repair [BG]' started by ComesATime, Jun 6, 2017.

  1. ComesATime


    Dec 12, 2012
    So here I am revamping a '94 Squier Series Jazz Bass.

    I got a new control plate--probably cheap Chinese-made components, but the cost was worth the control plate alone.

    I'm finding here's a lot of hum. I know single coils will be somewhat noisy, but it seems a bit more than necessary. I've shielded the inside with aluminum tape (using a multi-meter to ensure it is connected throughout). The tape completely silenced by P-Bass, so I'd like to do the same here, at least to some degree.

    I'm wondering if some of the samarium cobalt noiseless pickups and some new wiring will be an upgrade over the stock J-bass pickups in terms of silence. I've never used them personally, but I can get a set for $65.

    Both pickups in this bass are 3 and 5/8," so I assume It'll need a bit of widening in the bridge pu slot.

  2. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    If you want a totally silent Jazz bass you need to use humbuckers or balance both pickups. Anything labelled "noiseless" is going to be a humbucker so the pickups you suggested should be silent. Bear in mind that you will lose some top end when switching to humbuckers from single coils. There is a reason why single coil Jazz pickups are common.

    On the note of shielding, shielding does not address 60hz hum and humbuckers still need to be shielded. If you are intending to favour one single coil pickup, you will always be susceptible to 60hz hum regardless of pickup choice. You may not get hum everywhere but it will still be susceptible. The reason the P got totally silent with proper shielding is because it is already a humbucking pickup, there is an even number of coils. I am guessing the Jazz bass gets silent when you balance both volumes. If it still hums with both pickup balanced, does the hum stop if you touch metal/strings/bridge? If so, the bass requires shielding.
  3. ComesATime


    Dec 12, 2012
    Thanks for this.

    I think I'm going to take it in for a proper setup as the action is still too high. I removed the excess relief, but it's still up there, and I'm thinking the nut may need to be better filed, and I don't have those tools.

    I balanced the pickups and there was still hum even when touching the bridge. It could be the older pickups. It could be shoddy soldering or ineffective wiring on the plate. I'm going to open it up and take a look.
  4. Baltimore Bass

    Baltimore Bass

    Jul 14, 2016
    Yeah, that's odd. My Jazz doesn't hum at all when the volume pots for each pickup are balanced. Do you have any computers or fluorescent lights near you while playing? Does the hum change if you move the bass around?
  5. ComesATime


    Dec 12, 2012
    Turned a certain way towards the amp, it gets louder. Never quieter, though.

    I'm a bit of an amateur when it comes to soldering, so I went back in and reinforced any lackluster joints. I also reseated the ground wire I have running from the bridge PU cavity to the control cavity for shielding continuity.

    All of this and it's the same thing. The bridge ground is soldered to the pot and firmly pinned under the bridge with the strands splayed out.

    I'm really not sure what else, so I'm going to see if I can get it to my tech tomorrow if I get time, but he's going out on tour, so it might have to wait.

    Just a curious case. I feel like I'm missing something. I felt around to see if I could get less hum somewhere, but I came up empty.
  6. ComesATime


    Dec 12, 2012
    Ended up going over all of the shielding to make sure there was 000 readings. It was all damn close. Went in, shielded the pickups. Checked my grounds. Hum is still there, consistent whether I'm touching the bridge or not. Loud hum. Could it be the cheap pots, old MIM pickups?

    Only problem with replacing the pickups is the narrower bridge spacing.
  7. Baltimore Bass

    Baltimore Bass

    Jul 14, 2016
    I'd throw a set of Bartolini's in it and swap the pots. It'd be a major upgrade over the MIM electronics. That's weird it checked out ok on a meter though. Did you try different cables, amps, and rooms?
  8. hotbass57


    Nov 27, 2011
    I dropped those in my Fender MIM and boom no noise at all. Nice pick ups.
  9. JLS

    JLS Supporting Member

    Sep 12, 2008
    Albuquerque, NM
    I setup & repair guitars & basses
    Set it up for series wiring; this should be stock on all jazz-type basses.