Active preamp with passive pickups vs active pickups. What's the deal?

Discussion in 'Pickups & Electronics [BG]' started by Joe Nerve, Apr 23, 2019.


  1. Joe Nerve

    Joe Nerve Supporting Member

    Oct 7, 2000
    New York City
    Endorsing artist: Musicman basses
    I started a thread yesterday, but want to be more specific.

    Just purchased a Rockbass with passive MEC pickups and an active preamp. Some RBs have passive/passive, some passive/active, and some active/active.

    Questions:

    1. Will a passive bass with an active preamp sound exactly like a passive/passive bass - if the EQ is set flat?

    2. What is the difference in sound between passive and active pickups, if they both have an active preamp? I'd love to know specifically with the MECs but wondering also if there are any common, general differences.​
     
  2. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    1. up to the designers, Stingrays do NOT, BTW

    2. active can have more highs & be more quiet
    less windings on the coil mean it can achieve higher frequency output & at the same time less noise is induced by less wraps

    A downside of passive pickups is that the hotter you wind them the darker they get.
    Also, the hotter you wind them, the more likely they are to be noisy.

    hotter = more output (measured in Volts)
     
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  3. James Collins

    James Collins

    Mar 25, 2017
    1) Will depend on the preamp. MEC preamps sound the same bypassed and with all the EQ flat on every bass I own.

    2)
    Hotter also means more capacitance in the pickup which is what takes away the high frequencies. Capacitance builds up between the wires in the coil that functions like a capacitor wired directly to ground.

    I wish I could help you out with specifics about that pickup, but I would suggest waiting until you see it.

    Do you have a picture of the bass by the way?
     
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  4. Jazz Ad

    Jazz Ad Mi la ré sol

    The main practical difference is sensitivity to hum. Pickups meant to be used active only can have super low impedance which means no hum even with single coils and very even response. EMGs are king at this.
     
  5. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    More windings also means more Inductance, which will bring down the resonant frequency.
    This is why putting two pickups in series will bring down the resonant peak, because you're adding the Inductance together, whereas normally they operate in parallel & the summed Inductance is halved.
     
  6. Joe Nerve

    Joe Nerve Supporting Member

    Oct 7, 2000
    New York City
    Endorsing artist: Musicman basses
    If passive means less highs, that makes me happy. Warwick electronics can get way too sizzly for me. I had a German Active/Active Corvette and it had tons of bottom and sizzle, with not a whole lot happening in between. I'm hoping this bass has just a wee bit more mids.

    [​IMG]

    [​IMG]
     
    Last edited: Apr 23, 2019
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  7. James Collins

    James Collins

    Mar 25, 2017
    That's only part of the picture still, since there is the inductance caused by the change in the magnetic field when you pluck the string AND the inductive reactance caused by a changing current in a coil. It's like the more I learn about circuitry, the less I know.
     
  8. James Collins

    James Collins

    Mar 25, 2017
    Definitely looks all stock. I think you will be pleased with the electronics. My only complaint with the Rockbass electronics is the treble EQ is noisey all the way up and the pots on mine wore out after 20 years. But that bass is active pickups. Interested to hear your experience.
     
  9. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    unsure if you're kidding, because you just defined the very basic way in which an Inductor operates & pickups are Inductors.

    This is all sort of outside the scope of the question, anyway.
     
  10. James Collins

    James Collins

    Mar 25, 2017
    I will pm you.
     
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