1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
     
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Stacked Volume Pot from BBG ... Wiring Help

Discussion in 'Pickups & Electronics [BG]' started by CH Design, Aug 1, 2012.


  1. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    Hello there,
    Can anyone help me out with a wiring diagram or instruction for the Stacked Volume Pot w/ Center Detent (250K) that BestBassGear sells? I've tried asking the folks at BBG a few times and am having a hard time getting a reply. If it matters, I'm wiring it up to a set of Dimarzio J pickups (three wires from each PU) and then out to an EMG BQS Control preamp. Thanks in advance!
     
  2. Geoff St. Germaine

    Geoff St. Germaine Commercial User

    Which Dimarzio J pickups are they? The only ones I see have either two or four conductors.

    If they are three conductor then two will be hot and one ground. If it's a split coil then then two hot conductors should just be wired together into the volume pot. The stacked volume pot can just be wired like two single volume pots. There's a wiring schematic on the dimarzio website under the J pickups for a vol/vol configuration (http://www.dimarzio.com/sites/default/files/diagrams/ModelJ.pdf). You can just ignore the switch as you can't use one unless it's a 4 conductor if it's a split coil or if it has stacked coils. Since the dimarzio Js seem to be single coil or split coils, I assume it's neither of those. It seems weird to me to have a center detent on a volume pot, but it makes no real difference (makes sense on a b/m/t control or a blend).
     
  3. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    Thanks for the reply!

    I am using the Dimarzio Ultra Jazz™ Pair DP149. I'm pretty sure there are only three wires coming out of each pickup. I don't think any of them was a shielded wire, but I'll double check.
     
  4. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    I just checked. Three wires ... Red, Green and Grey.
     
  5. Geoff St. Germaine

    Geoff St. Germaine Commercial User

    I think it's probably the 549 here: http://www.dimarzio.com/sites/default/files/diagrams/UltraJazz5.pdf

    This has the red, green and grey wires as described. For a normal installation you can just connect green and grey. If you need to reverse the phase of the pickup you connect red and grey to ground. Grey is the ground and red and green are the ends of the coils that are internally connected in series. The switching in the pdf is phase switching so the switch just flips red and green to either hot or ground. Hope this helps.
     
  6. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    But where do the wires from the pickups go on the pot? The pot has two rows with three lugs each. Do I just treat them the same as the lugs on a normal (i.e. single) volume pot?
     
  7. Geoff St. Germaine

    Geoff St. Germaine Commercial User

    Yeah, it's just two pots sharing the same shaft axis. They're electrically and mechanically separate. You can wire each pickup to each set of lugs independently of the other pickup and lugs.
     
  8. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    Ok, so if I have this right... The top set of lugs should be wired input (from the pickup), output (to the preamp) and ground. Because the volume pots are in parallel, the second set of lugs is reversed (output, input and ground). That's straight forward.

    To connect to the preamp (EMG BQS Control), I only have one spot to connect too (one white wire and one black wire). Does that mean both outputs from each set of volume lugs get connected together and then go to either the white or black wire. I assume the ground goes to the other.
     
  9. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    I did a little more reading which has led to a little more confusion. Do both volume pots get wired backwards (output, input, ground) when they are in parallel?

    Also, despite what it says on the BBG website, this pot does not have a center detent on either control.
     
  10. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    I think I have it figured out now. Inputs from pickups go to the center lugs. Output from top pot goes to output on bottom pot to the white wire off of the board. The black wire from the board goes to the ground on the pots. Maybe? I'll hook it up tonight and see what happens.
     
  11. CH Design

    CH Design Supporting Member

    Apr 25, 2007
    Ottawa, ON
    Got it. Thanks Geoff!
     

Share This Page