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who is knows about pots??

Discussion in 'Pickups & Electronics [BG]' started by Tajue17, Jan 14, 2013.

  1. I have a 98 fender factory hot rodded P so its a passive P/J config thats stock fender .. well theres a dead spot in the tone knob and what its doing is making the bass die while playing,,,I originally thought it was the GK amp but I know now its that tone knob and you can feel a little hard area when turning right where the dead spot is..
    okay so what I wanted to ask you guys is I'm really thinking about having all the pots (V/V/T) replaced and upgraded because I'm wondering if their cheap anyway but what is the best replacement out there that I can keep passive,,, what should I buy??? I'd like to keep it the same "types" of pots sound wise I guess or the tone amount is fine.. I also want to upgrade the plug jack to the best one I can get.

    thanks for any info.. T
  2. RedLeg

    RedLeg Supporting Member

    Jan 24, 2009
    Kaiserslautern, Germany
    Nov Shmoz Ka Pop?
  3. Bassamatic

    Bassamatic keepin' the beat since the 60's Supporting Member

    You might be able to clean the pot with a little electronic cleaning spray, but it is not a big deal to replace them. The Bourns are very good quality and should last a long time, but the CTS and Alps are also very good. The make or type of pot has no effect on the sound. All that counts is the proper taper, A or B as marked on the old ones, and the value - probably 250K

    As I think about this - are you sure it is the TONE pot causing the problem and not the VOLUME pot? The tone pot should not be able to kill the sound no matter what it does. The way they are wired they can only affect the tone. If it IS the tone pot, there may be some problem with the wiring instead, where when you move the pot the signal gets shorted or cut. Get it checked.
  4. Turnaround

    Turnaround Commercial User

    May 6, 2004
    Toronto Canada
    Independent Instrument Technician, and Contractor to Club Bass and Guitar - Toronto
    I think you mean .047 mfd cap.
  5. bumperbass


    Jun 19, 2012
    If the tone pot were really screwed up badly, I can see where the signal could be shorted right to ground; i.e. if the wiper is somehow contacting the case.
  6. Kevin aka Kebo

    Kevin aka Kebo Commercial User

    Nov 17, 2011
    Princeton NJ
    Owner - Kebo's Bass Works
    My advice if you cant spray the pot out - CTS pots, be sure to change the jack to a switch craft and an orange drop. Hoagland brothers sell these pre wired and its only like 15 bucks more than the raw components. I use there stuff often
  7. RedLeg

    RedLeg Supporting Member

    Jan 24, 2009
    Kaiserslautern, Germany
    Nov Shmoz Ka Pop?
  8. thanks for the posts,,, it is the tone pot thats killing sound when you turn it you can feel a hard spot at about 6 oclock which cuts out and then comes back in at about 8 oclock..

    not sure what you guys mean with the 47cap stuff though,,, but I'm thinking for the two volumes get the 250k's and the tone get the 47 cap?? then a swith craft or orange drop.. also do you think any decent luthier will install these for me if I bought them first?
  9. llldino


    Dec 16, 2012

    It does sound like the tone pot is bad. You shouldn't have to replace your volume pots, or your capacitor, just desolder all your components and replace the pot. If your uncomfortable with desoldering, you could just get a new cap online or in an electronics store and rewire everything. Your looking for a 0.047 microFarad capacitor. Make/shape doesn't matter.

    Im not sure if a luther would get into the electonics. If he did, he would charge you up the ass for what could be a really quick and easy fix. Soldering is fun anyways :hyper:
  10. okay Im getting it figured out so check this out,, I need
    1 oprange drop 47capacitor
    3 Bourns 250K pro audio guitar pots (Volume/Volume/Tone)

    Plug Jack, switchcraft?

    should I have the cavity shielded too while all this is being done even though its passive?

    what else??? is there something else I'm forgetting? I decided I want to have the neck pleked also so I'll find the best guy to handle everything for me.
  11. llldino, we posted at the same time,,, I can also have the luthier check it all out but the reason for replacing everything is I wonder if the stock stuff is kinda cheap and should i just be done with all that and get something in there more quality,, where I decided to not sell that bass.

    microFarad,,,, is that better than the orange. alsoa re these like filters or something are they a big deal?

    as far as desolder ALL the componets,, it might be fun at first but when it comes to reconnecting everything IDK..
  12. llldino


    Dec 16, 2012
    Like I said, I'm not sure if luthers would know how the electronics work, although i'm sure most of them do.

    When it comes to pots, buying a higher quality pot will not change the tone of the guitar, so you might as well save yourself some work and leave the volume's where they are. If you insist on changing them, your going to have a lot more work ahead of you.

    A capacitor (cap) is basically a high-pass filter when it comes to passive electonics. Just like batteries are rated 9 volt, 20 volt ect... capacitors are measured in a unit called a microfarad. The cap that came stock with your p is more likely than not a 0.047 microfarad cap. If you want the same tone from your bass, you must replace the cap with one that is also 0.047, or you can reuse the cap. The brand of cap does not matter at all, a 20 cent cap will sound exactly the same as a 5 dollar cap.

    I suggest keeping everything where it is and replacing just the tone pot. Desoldering the old cap is a bitch so I would just get a new one.

    Follow these schematics

  13. RedLeg

    RedLeg Supporting Member

    Jan 24, 2009
    Kaiserslautern, Germany
    Nov Shmoz Ka Pop?
    Shielding is always a good thing to do if you are going to be performing open guts surgery on your axe. What is the make and model of your bass? the bass may already have conductive paint applied.
    as for which capacitor or which brand, that is total user preference. I like bourns and orange drop, but I am susceptible to what I read on the talkbass!
  14. okay I took the bass apart tonight to get a look inside,, up until now I thought my bass was a 1998 US Fender hotrodded P-bass (P/J), but tonight I learned my bass has 3 different dates in the neck joint, July 25, Aug 2nd and Sep 11th 2000. I also have to agree with llldino that replacing everything will be a pain so I will just try to replace the tone pot but I'll do the cap too because its the same solder joints and the new cap will have longer legs or connectors to work with. I'll hold off on the jack too until the tone pot is done 1st to be sure.
    as far as shielding there is non inside the cavity just the same colored paint as the finish, the pick guard has foil tape on it though where the cavity is so maybe thats all they did then. as far as me I am a licensed plumber and I've done alot of soldering on pipes so I should be able to get it,, but should I buy a certain solder gun for this and what size solder and lastly do you guys flux this stuff or just sweat it dry? thanks for any tips.

    oh if this goes right I'm thinking abvout building a bass because #1 I'm old and bored and #2 it was always the electronics that scared me,, I may have a cool hobby on my hands..

    I can see the pots in there now are all CTS pots but I cannot make out if they are A or B??
    also thanks for the links to schematic,, would that be the same wiring for a P/J pickup?
  15. llldino


    Dec 16, 2012
    I find shielding unnecessary; you will always have some inherent noise from your single coil pickup and shielding only blocks E-fields outside the instrument such as fluorescent lighting/cpus ect..

    For soldering, I wouldn't use a gun over 60W as the higher temperatures can wreck the electrical components. I personally use 25W, and get by just fine. As for solder, make sure you buy electrical solder and NOT plumbing solder like I did. Electrical solder has a rosin core and is a requirement for making the solder stick to your wires/components. Don't buy acid-core, this crap is used for tacking sheet metal I think.

    There are different kinds of solder out there; I personally use 60/40 mix of tin/lead which I had a hell of a time finding. Most solder out there nowadays is lead-free and I find that it takes longer to heat up and stinks way worse than the lead stuff. The smaller the solder, the easier it is to feed into the joint your soldering.

    Also, the schematics should be the same. If your getting a new cap, make sure it's 0.047 microfarads, anything else might change the tone of your bass, but on the other hand I just threw a 0.1 mfd cap into my bass and i'm loving the sound.

    Good luck.
  16. llldino,,, thanks man.. I'm going with what you currently use and I'll get that solder with the gun. curious about the 0,1 cap you used,,, is it brighter or less tone? I'm thinking they are cheap enough so i can try a few different things and I might find something I like better than stock?
  17. SGD Lutherie

    SGD Lutherie Banned Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    You need a .047µF cap, not 47. You don't need an orange drop unless you just like the way it looks.

    For a Jazz bass use linear taper for the two volumes and audio taper for the tone.
  18. llldino


    Dec 16, 2012
    The 0.1 cuts a lot of the treble and some of the midrange compared to the 0.047. I find myself using the 0.1 with the tone control at around 3-5 alot more than the 0.047