Make an active bass passive? Bass guitar wiring?

Discussion in 'Pickups & Electronics [BG]' started by Static119, Aug 3, 2010.


  1. Static119

    Static119

    Joined:
    Jul 31, 2010
    So I've got a set of passive Lollar PJ pickups that I'm really itching to put into something. I came across an Ibanez SR800 that has the PJ pickup config but the pickups are active.

    Now, I'm not very knowledgeable on bass guitar wiring or really electronics in general. I installed some passive humbuckers into a guitar once and I've taken the backplate off of all of my basses and have poked around, trying to see how everything works. I kind of get it, and I'm decent at soldering.

    So, in theory, would it be possible to just throw some passive pickups in this bass and call it good? Should I buy an active preamp so all the knobs get to keep their jobs?

    Could I just customize the electronics totally to my own tastes? Could I strip the pickups and the electronics out of the SR800 and put my own preamp in along with the passive pickups and wire it out the way I want it? Would it be possible to turn one of the knobs into an active/passive switch?

    I'd really appreciate ANY advice here.
  2. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    You can rewire the bass any way you want.

    Are just the pickups active, or does it have a preamp?
  3. Static119

    Static119

    Joined:
    Jul 31, 2010
    It's got an active EQ. My knowledge is quite limited as I mentioned earlier.

    I also just read something about pots and how you have to match the pots to the output of the pickups other wise the tone will be too muddy or too tinny. So I'll have to redo the ENTIRE thing right?
  4. Muaguana

    Muaguana

    Joined:
    Jul 28, 2009
    If the pickups, themselves, are active, you'll need different pots for the passive ones. And if you want a passive tone knob, you'll have to get a capacitor and wire one yourself.
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  6. James Judson

    James Judson

    Joined:
    Jul 16, 2009
    All pickups are passive. What makes a guitar active is the preamp. How can you tell the difference? A preamp needs power (battery). I would look on line for a schematic and install your "passive" pickups without preamp. Passive schematics are extremely simple. You could try your "passive" pickups with the preamp but the results may be unpredictable. There is a bunch of engineering to match pups and amps (like impedance matching). Good luck with your project and let us know how it turns out.
  7. Muaguana

    Muaguana

    Joined:
    Jul 28, 2009
    Actually, there are active, battery-powered pickups on the market. Ever heard of a little-known company called "EMG"?
  8. line6man

    line6man

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    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    Absolute nonsense!

    Active pickups are relatively rare compared with passives, but they definitely exist.

    EMG and MEC are well known for their active offerings.
  9. line6man

    line6man

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    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    Pot values are a personal preference based on how much output and treble you like.

    You don't want to use 25K or 50K pots with high impedance (passive) pickups though, because the low resistance will divert most of the signal to ground.
    And you don't want to use 250K/500K/1M pots with low impedance (active) pickups, because they will act as an on/off switch rather than a usable control.
  10. Static119

    Static119

    Joined:
    Jul 31, 2010
    This is starting to sound kind of expensive. I think I'm going to keep scouting around for a Fender or a cheapo bass that would be easy to stick my pickups in, but if I manage to sell my GW35 I'll have enough spare cash to dive right in!
  11. TheMutt

    TheMutt

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    Apr 28, 2007
    Location:
    Covina, California
    Disclosures:
    Operations and Warehouse, Guitar Center Rancho Cucamonga
    In theory, without much knowledge about the bass or preamp, yes you could do that. However, the particular preamp may require active pickups, which would be incompatible with your Lollars.

    You could always strip the bass of both pickups and the preamp and install a passive wiring harness with something like vol/tone for each pickup since there are four spots for controls.

    This is also possible, but may be more difficult than you'd imagine. More on that below.

    This is possible, but in practice it is much better to get a preamp that has an active passive switch built into it. This way, you still have the versatility of having an active instrument plus the capability to go passive, while being able to use the volume knob and possibly a tone knob. More on this below as well.

    I have personally changed out the pickup and preamp on my Stingray 5 bass. I changed the stock pickup out with a Nordstrand MM 5.4 and the preamp out with a Glockenklang preamp. It was a bit of a chore to wire everything up, but once I finally did, I had a bass with a better inherent tone (my SR5 had a ceramic pickup, which I changed to a darker-voiced Alnico V pickup) that was able to switch to active/passive and has, IMO, better EQ points than the stock preamp did.
  12. Static119

    Static119

    Joined:
    Jul 31, 2010

    Thanks. I'm glad to know that it is possible. And I understand that it will be a long, tedious project. However, the learning process and the end result could prove to be invaluable. :cool:
  13. line6man

    line6man

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    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    That would only be the case if the preamp has a low impedance input.

    Most preamps (At least that I'm aware of. I could be wrong.) have an input impedance at or above 1M , which is perfect for high impedance passive pickups.
  14. TheMutt

    TheMutt

    Joined:
    Apr 28, 2007
    Location:
    Covina, California
    Disclosures:
    Operations and Warehouse, Guitar Center Rancho Cucamonga
    Yes that is certainly the case as far as most preamps are concerned. However, I only said that with minimal knowledge (as in, I know that the bass exists) of the bass and the pickups/preamp inside. ;)
  15. Static119

    Static119

    Joined:
    Jul 31, 2010
    Hello everyone!

    Just finished installing my pickups into an Ibanez SR300DX. The wiring was very straightforward and I am quite pleased with the result. Thank you all very much for the advice.

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