Troubleshooting a cheap active bass - do I have this right?

Discussion in 'Pickups & Electronics [BG]' started by Rich Fiscus, Dec 20, 2015.

  1. Never mind. Clearly I can't explain myself well enough to discuss this here.
    Last edited: Dec 21, 2015
  2. An active system may use an opamp, or it may use discrete transistors, or in some cases, even vacuum tubes. There are many different ways to achieve the end goal of buffering a signal path. Buffering does not "overcome impedance loading from connecting higher impedance outputs to lower impedance inputs." Typically, your buffer will have the same input impedance as your amp, so the pickups will see the same resistive load.

    The EQ IS your buffer.

    I'm not sure what you mean by "an active tone suck," but buffering comes from the preamp. You don't need an active blend pot to get it, unless you want the features that an active blend pot provides.
  3. -
    Last edited: Dec 21, 2015
  4. I don't think you are understanding that your EQ IS the buffer/preamp. You can't have an EQ that doesn't buffer the signal and provide a low impedance output.

    200k is an atypical input impedance for passive pickups. Usually the goal in having a lower input impedance is to prevent noise, but if you go too low, then there will be a lot of loading on the pickup coils. IIRC, some EMG stuff has a 500k input impedance, but otherwise, 1M is pretty standard.
  5. JustForSport


    Nov 17, 2011
    As stated above, the EMG EQ IS a buffer, as well.

    The EMG EQs can work with either passive pickups or active pickups, the difference being the value of the bal pot and vol pots between the pickups and the preamp (EQ/buffer).

    Bal pots (except for EMG ABC) and vol pots, incl tone pots are all passive. But their values are different depending whether passive or active pickups are run to them.

    EMG ABC pot is not needed with an EQ/buffer. If it would have much affect between passive pickups when used with a preamp/buffer/EQ, IDK.
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