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Messin' with tone pots

Discussion in 'Pickups & Electronics [BG]' started by Chef, Aug 20, 2004.


  1. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    The bass: 1972 (?) tele bass with big fender humbucker.
    Problem: it's too dang "bassy."
    Can I brighten it up by swapping in a different tone pot, or resistors or something?
     
  2. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    how do you use the tone pot? Do you always have it all the way up?

    In case you don't know, in a passive system the tone pot only reduces the highs - so when the tone control is at max the minimum cut is being applied and vice versa.

    The issue might be the pickup itself.
     
  3. AlembicPlayer

    AlembicPlayer Im not wearing shorts

    Aug 15, 2004
    Pacific Northwet, USA
    first try lowering the pickup..
    what are the value of the pots? if you increase the pot value, more highs will come thru. For a humbucker, it should be 500K..and if that's still not enough..you can try a 1 meg.

    but I would put a meter on the pots and measure the true value and make sure they are up to what they're supposed to be.
     
  4. tplyons

    tplyons

    Apr 6, 2003
    Madison, NJ
    Problem: too bassy.
    Solution: don't play it. No offense, but I wouldn't mod that thing for anything. Keep it original.
     
  5. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    What do you mean by "bassy"? Do you mean "boomy", like relative to the mids, or are you saying "not enough highs"? Those are two different things. Have you tried using the EQ on your amp?
     
  6. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    I mean too bassy. Not mids. Even with stainless rounds on it it's not very bright either. Yes, I've tried eq.
     
  7. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Okay, there's probably only one answer then: replace the pickup. If as tplyons says there's some "vintage value", just sell it and get a bass with a tone you like. Guessing a '72 tele in good condition should fetch some pretty good bucks on the secondary market. Otherwise, if you like the rest of the bass and you don't mind modding it, replace the pickup. Chances are good you can make that "reversible", so you can put the original pickup back in if you ever do decide to sell it. If you have to drill extra holes in the instrument, it'll definitely lose some of its vintage value (assuming it's in good shape).
     
  8. AlembicPlayer

    AlembicPlayer Im not wearing shorts

    Aug 15, 2004
    Pacific Northwet, USA
    I disagree..you may not need to change out he pickup.

    changing the pots to a higher value will make it brighter..that's a fact.
     
  9. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    True, and it's worth trying. But it may as equally need a pickup change if the sound itself is producing a sound that's too bassy.

    Putting in 500K or 1Meg pots will let more of the natural highs through. but if the pickup isn't producing them in the first place then it won't necessarily help. But you're right, probably worth a try and almost certainly cheaper than pickup change.
     
  10. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    I'll look into the value of the tone pot and replacing. Thanks for the ideas on what value to put in there. If I do anything with the pcikup, it will probably be to send it to Carey Nordstand, and let him make a new one to fit under the stock cover...I don't want to mess up the old one by rewinding, or do anything unreversable that would have an impact on it's value. I do love playing, it's got a great neck/feel, and it's just a cool looking axe in the old vintage creme finish;)
     
  11. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    The volume pot will usually make a more noticeable difference, in my experience. Don't forget to play with cap values too, or even just try unwiring the tone pot completely.
     
  12. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    I *think* I bypassed the tone pot about two years ago, but I'd have to open her up to remember. Explain about the volume pot, and caps (capacitors, right?)...I don't think there are any...
     
  13. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    OK, if you bypassed the tone pot then you could leave that alone.

    As I said previously about the vol pot:

    If you have both vol pot and tone pot in the signal chain, you have to change them both. Otherwise, if you changed the vol pot only to 500K then the extra highs let through by the vol pot would be negated by the 250K tone pot if that's in the signal chain.

    About the capacitor on the tone pot, that's only for if you're using the tone control.

    If your tone pot is in the signal chain and you're not using it, then the cap value really doesn't matter as there is highs being cut from the tone with the pot at full. If it's not in the signal chain, then you could replace the cap with broccoli for all the difference it'd make.
     
  14. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    David, you're obviously a lot more electronics savvy than I. Let's say for the sake of arguement I swap both pots to 500 (or 1K), what cap should I run with the pots, and there's just one with the tone pot eh? Any good reading I can do to get smart on this? Basic guitar electronics 101?
     
  15. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    Chef,
    there's no reason you can't use the same cap with the tone pot. If you're changing the pots, I'd probably recommend keeping the cap constant so that you're not changing everything at the same time. Unless you don't like the current tone pot operation?

    As for the reading/learning, I learned a huge amount from reading here. I also read wiring diagrams at the seymour duncan, bartolini and aguilar websites. Also read stuff at guitarnuts.com. There's a book 'guitar electronics for musicians' for donald brosnac. It's more of a pickup reference book, but I found it useful stuff.
     
  16. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    If you have both vol pot and tone pot in the signal chain, you have to change them both. Otherwise, if you changed the vol pot only to 500K then the extra highs let through by the vol pot would be negated by the 250K tone pot if that's in the signal chain.

    It's not quite that simple, unfortunately, although in practice it may sound that way in many cases. Two 250K pots (volume + tone) in parallel, one 500K and one 250K, and two 500K pots, will all have different loading effects on the pickup, and the cutoff frequency of the tone control will be different in each case. To complicate things, the midrange emphasis will shift as well, as soon as you actually use either the tone or volume controls. Just using the same cap may or may not make you happy, but you won't necessarily be keeping the cutoff frequency as a constant if you do that and change pot values.

    I'd suggest a trip the the Ampage pickup forum at www.firebottle.com for anyone who wants to check out the ugly math. I'm feeling a little lazy tonight, sorry. :cool:

    Chef, you might play with a treble bypass cap too, if you ever turn your volume control down. If you go to a higher value volume pot, this can be especially helpful.
     
  17. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    I tend to play with both pots dimed, and get tone and volume changes from my right hand finger attack, if ya follow...
     
  18. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Me too. I'd just try losing the tone control, and increasing the value of the volume pot. If it's still not bright enough, on to the pickup.
     
  19. A9X

    A9X

    Dec 27, 2003
    Sinny, Oztraya
    Well then, first experiment should be to bypass BOTH the volume and tone pots, and wire the pickup direct to the output socket. This way, you'll be hearing what your pickup can do without any of the loading effects of the pots/caps in circuit. If you do this and still don't like the way it sounds, then it might be time to change the pickup for something else.

    If you haven't already, I'd also suggest you try the bass into other amps (use a friends or go to a store) to see if the tone signature follows with the bass. If you hear something radically different, it might be a combination of the bass and the amp.
     
  20. Chef

    Chef Moderator Staff Member Supporting Member

    May 23, 2004
    Columbia MO
    Staff Reviewer; Bass Gear Magazine
    I've got a whole slew of amps to choose from, the tone definately follows the bass...