How to wire a Passive Tone Control in active bass when passive?

Discussion in 'Pickups & Electronics [BG]' started by FunkyMan, Jan 20, 2013.

  1. FunkyMan


    Nov 27, 2007
    Hello folks! The title says it all! The bass is a Jazz Bass build, the original idea is to put an Aguilar OBP-3 preamp, and install a stacked pot where the original single mid pot is supposed to be, so the lower pot should work as tone control when passive..

    So you think all this is possible? The control plate should be like this:

    -Vol Neck
    -Vol Bridge
    -Stacked pot: Upper is Mid, Lower is Tone Control when passive (What value should be this pot?)
    -Stacked pot: Bass and Treble
    -2 DPDT Switches (must do drill) One for Active/Passive, the second for Mid Frequency selection (Aguilar feature)

    The Body isn't built yet, so i think i can route the control cavity a little wider for all this, other things such the jack would be side mounted, and i'm thinking of a battery box for the battery, so i think i have enough room.

    Thank you, and sorry for let you read the worst english you've ever seen LOL

    (Oh my god, the title is so redundant........................)
  2. goran


    Dec 17, 2002
    Endorsing Artist: Bartolini
    Excellent! I want to know the same thing.
  3. khutch

    khutch Praise Harp

    Aug 20, 2011
    suburban Chicago
    I don't have the time to look up the specs for your preamp but the problem you often face with a stacked mid/passive tone control is that the preamp wants a 100k or lower pot and the passive tone control wants a 250k or higher pot. That is a difficult stacked pot to find. There is a Danelectro 100k/1Meg pot that you can find on some guitar parts websites and that should work in many cases. Otherwise you would be better off stacking the volume pots and using separate pots for the mid and passive tone. The two volume pots want the same value and same value stacked pots are easy to find. The single mid and passive tone pots then can be any values they need to be.

  4. The active/passive switch and tone control will be done like this:
    The rest of the diagram should already be on the Aguilar website.
  5. It may be tough to find a pot for this, as two different values will be needed. Perhaps you can find a pot that can be disassembled easily, and swap the resistive elements, to get the proper combo.
  6. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    This'll definitely make the tone pot work only in passive mode, but won't it cause a pop when it returns due to the ungrounded preamp input in passive mode?
  7. FunkyMan


    Nov 27, 2007
    Hello Ken, and thankyou for your response, i think that your idea is the way to go in case i can't find the proper pot for the original purpose, but i'm doing separate Volume/Volume because i bought 2 push/pull pot so i can use the series and parallel options that the Dimarzio Ultra Jazz Pickups offers, so now i have 2 options:

    -Stacked Vol/Blend - Pasive Tone - Mid - Stacked Bass/Treble


    -Volume push/pull - Volume push/pull - Mid - Stacked Bass/Treble and No pasive tone control:(