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Custom circuits?

Discussion in 'Pickups & Electronics [BG]' started by Wolzly, Nov 5, 2005.


  1. Wolzly

    Wolzly

    Oct 16, 2005
    I was thinking about changing my 2 250k pots (volume, tone) for 2 Dual Concentric pots and maybe throwing in some "toys". This for example looks kinda cool... and if there are other things like that to throw on I'd look into them as well...

    I have a couple questions though... #1 would be, what's the difference between the 250K, 500K, and 1M pots? I know that the ones in my bass are 250K, but what would the difference to the sound be if I changed them for 500K? I ask because these dual concentric pots are 500K (although maybe that's 250k for each knob?)...

    Also... will adding more stuff hurt the sound of my bass? Forcing the current through more and more gadgets has got to do something, right? Although maybe I could find Dual-Concentric No-Load pots? Do they exist?
     
  2. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    500K pots can make a difference in your sound. How much depends on your pickups, woods etc. I've heard more highs when using 500K pots.

    If you're adding any circuitry onboard, make sure it's bypassable incase of circuit / battery failure as well as for general tone suckage reasons
     
  3. mahrous

    mahrous

    Aug 13, 2005
    Egypt
    in general, high resitance pots give you more highs and open up the sound of your pickups.

    as far as i know, a pot has the same resistence in all knobs. so a 500 concentrics doesnt mean 250k
     
  4. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    As others have written, 500K pots will attenuate highs less than 250K pots (assuming that you have a passive bass, that is).

    You'll probably want to change the value of your tone cap too if you're going with 500K controls.

    I found these reviews of the Black Ice Module you're thinking about over at Harmony Central:

    http://www.harmony-central.com/Effects/Data/Stewart_MacDonald/Black_Ice_Overdrive_Circuit-1.html

    One reviewer wrote that Stew-Mac suggests 250K pots (and relatively hot pickups) but they used in on a guitar with 500K pots.

    My guess is the 250K suggestion is to slightly roll off the highs to prevent the Black Ice from sounding harsh.

    Since it's a passive device, I believe the Black Ice module features a pair of diodes for clipping the signal. As users have written, if you play soft (i.e. low output signal (beneath the 0.7 volts that a diode needs to turn on)), no distortion. The harder you play, the more clipping you get.

    If you go that route, please let us know how it works out!

    Have fun!!!
     
  5. A dual concentric 500K pot has a value of 500K on each pot.
    To contrast this example, there are dual concentric pots that have different values such as 500K/250K.
    Both values will be described, and hopefully, marked on each pot.
    But if there is only one value listed for a dual concentric pot, both pots are the same value.
    OGB
     
  6. fjadams

    fjadams Supporting Member

    Jun 7, 2011
    Danbury, CT
    Would it be possible to use a 250/500 dual concentric pot with a .047 drop cap on the 250 side and a .022 drop cap on the 500 side as a tone control on a two pickup bass?
     
  7. I don't see why not. I can't hurt anything.
    It becomes a matter of personal preference.
    If you like how it works, then it is a cool mod.
    If not, then it was at least an interesting experiment.
    I'd be interested to know how you like it.
    OGB
    PS. How about also adding a switch to change which pup operates with each pot/cap combo?
    Especially if the two pups are different styles like in a P/J setup.