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Tone Cap Question

Discussion in 'Pickups & Electronics [BG]' started by spellcaster, Jul 19, 2013.


  1. spellcaster

    spellcaster

    Joined:
    Mar 20, 2007
    Location:
    Brooklyn
    Anyone know if this is a correct cap for a 74 Fender and how to test it on a basic multimeter? Thanks!

    [​IMG]
     
  2. Hopkins

    Hopkins Supporting Member

    Joined:
    Nov 17, 2010
    Location:
    Houston Tx
    That is a .01uf ceramic capacitor.

    Someone more knowledgeable than I am will have to tell you what the correct factory value for a 74 Fender would be.
     
  3. Steve Dallman

    Steve Dallman Supporting Member

    Joined:
    Mar 5, 2006
    Location:
    East Central Wisconsin
    I like .01uF on a passive bass and find it more useful than the usual .047uF or .1uF.
     
  4. spellcaster

    spellcaster

    Joined:
    Mar 20, 2007
    Location:
    Brooklyn
    Thanks! This is the cap that came in the bass when I bought it.
     
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  6. megafiddle

    megafiddle

    Joined:
    May 25, 2011
    If your meter has a capacitance function, you can read the value directly.
    It should be within 20 percent of it's marked value.
    M indicates 20% tolerance.

    So it should read between .008 and .012 uF.

    If you don't have a capacitance mode, you can check that it isn't shorted with the
    ohmmeter mode. It should read open. That's about all you can tell with a meter without
    a capacitance measuring capability.
    If it does read open, you can then simply try it in the circuit. If it seems to be working
    as expected, it's likely within tolerance.
     
  7. spellcaster

    spellcaster

    Joined:
    Mar 20, 2007
    Location:
    Brooklyn
    Tried a .47uf The bass did open up the sound but I switched back to the .01uf. On this bass it adds a thickness that certainly seems to work well and sound great. May experiment with some other vaules in the coming weeks.
     
  8. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    Do you mean 0.047uF? 0.47uF will almost certainly turn a high impedance signal into mud.
     
  9. spellcaster

    spellcaster

    Joined:
    Mar 20, 2007
    Location:
    Brooklyn
    Yes did mean to say, 0.047uf. Thanks for pointing that out.
     
  10. GlennW

    GlennW

    Joined:
    Sep 6, 2006
    Are you saying the .01uF cap is darker sounding than the .047uF cap?

    If yes, the .01uF might be a .1uF.

    The smaller the value, the brighter the sound; larger value, darker sound.
     
  11. spellcaster

    spellcaster

    Joined:
    Mar 20, 2007
    Location:
    Brooklyn
    Hey Glenn. Yep, the sound became darker with the cap pictured vs the orange drop .047uf I tried.
     
  12. GlennW

    GlennW

    Joined:
    Sep 6, 2006
    If the ".01uF cap in question" in the pic is darker sounding than a known .047uF cap, it's a .1uF and not a .01uF.
     
  13. Hopkins

    Hopkins Supporting Member

    Joined:
    Nov 17, 2010
    Location:
    Houston Tx
    103 is the value, its 10, with three 000s pf which is 10,000pf which is .01uf
     
  14. GlennW

    GlennW

    Joined:
    Sep 6, 2006
    So a 104 is a .1uF cap?

    If the cap in the OP's pic is a .01uF, maybe his .047uF cap isn't .047uF? A .047uF should sound darker than a .01uF.
     
  15. Hopkins

    Hopkins Supporting Member

    Joined:
    Nov 17, 2010
    Location:
    Houston Tx
    Yep a 104 would be a .1uf.
     
  16. GlennW

    GlennW

    Joined:
    Sep 6, 2006
    I never realized there was a correlation between that number and the value.

    Thanks, you taught me something.
     
  17. Hopkins

    Hopkins Supporting Member

    Joined:
    Nov 17, 2010
    Location:
    Houston Tx
    I just learned this recently as well. I have no clue how the numbers would work on a cap value that wasn't a derivative of 10
     
  18. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    The derivative of 10, and of all real numbers, is 0.

    What do you mean, though?
     
  19. megafiddle

    megafiddle

    Joined:
    May 25, 2011
    Designations of that type (103) on caps work exactly the same as the resistor
    color code, except that it uses the actual digit instead of the color bands.

    A resistor of 10,000 ohms would use brown, black, orange, which represents
    1, 0, 3 :
    1, 0, followed by 3 zeros, or 10,000.

    Likewise for a cap, 103 is
    1, 0, 3 :
    1, 0, followed by 3 zeros, or 10,000.
    but in this case the units are pF, not ohms.
    To convert pF to uF, divide by 1,000,000. (move the decimal point 6 places to the left)

    A 47,000 ohm resistor is marked yellow, violet, orange, which represents
    4, 7, 3:
    4, 7, followed by 3 zeros, or 47,000
    and this is in ohms.

    And a .047 uF cap would be marked 473:
    4, 7, followed by 3 zeros, or 47,000
    and again, this is in units of pF.
    Divide by 1,000,000 to get .047 uF.

    Other types of caps, might be marked with 3 digits, but the units are nanofarad (nF).
    You have to know which system is being used, but they are more or less consistant
    for a particular type of cap.

    If you ever see a p or an n mixed in with two numbers, the p or n indicates two things:
    it indicates that the value is in picofarads or nanofarads respectively, and it also
    indicates the position of the decimal point.

    2n2 is 2.2 nanofard
    4p7 is 4.7 picofarad
     
  20. Hopkins

    Hopkins Supporting Member

    Joined:
    Nov 17, 2010
    Location:
    Houston Tx

    Great post man. Very informative :bassist:
     
  21. GlennW

    GlennW

    Joined:
    Sep 6, 2006
    Megafiddle, thanks for that info.

    If I'm not mistaken older caps were marked differently, the abbreviated value (not the numbers). Note the "MFD" instead of "uF" in the pic.

    And now for some mojo :D
     

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