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confusion with pre-amps

Discussion in 'Amps and Cabs [BG]' started by steve-gan, Feb 5, 2003.


  1. steve-gan

    steve-gan

    Aug 6, 2002
    I'm confused on the purpose of pre-amps as well as how they are used with amp/cabinets and/or PA systems. How do pre-amps relate to basses with passive or active pick-ups? thanks-steve:confused:
     
  2. 5stringDNA

    5stringDNA

    Oct 10, 2002
    Englewood, CO
    The pre-amp in your bass boosts the signal to your amp, thus giving you more volume. Virtually all pre-amp also have some sort of EQ on them for adjusting the frequency of your bass's output, thus shaping the sound before it hits the mixing board or amp's EQ circuit.
     
  3. StingrayKid21

    StingrayKid21 Holding down the low-end since 1996.

    Oct 7, 2001
    Portland, OR
    Hey Steve,

    I'll take a shot at explaining preamps as I understand them.. anyone feel free to correct me if I make a mistake.

    The point of preamps in general is to modify the signal that will eventually be amplified by the power amp and sent to the speaker cabinets. So they pretty much act as means of altering or fine tuning your sound.
    Passive basses do not have preamps as far as I know. They usually will have a volume and a tone control (which I believe can "roll off" some of the higher frequencies), and sometimes pan controls if the bass has multiple pickups, but you cannot add to any of the frequencies, you can only cut. In this case, any other signal modification must be done with a separate preamp unit.
    Basses with active preamps require a battery to power the electronics. The active preamp allows you to boost and cut certain frequencies (bass, treble, mid) directly on the bass itself, rather than on a separate preamp unit.

    I hope that helps a little.

    --Justin
     
  4. Brad Johnson

    Brad Johnson Commercial User

    Mar 8, 2000
    Gaithersburg, Md
    Boom Bass Cabinets, DR strings
    In the bass world there are preamps that feed power amps and there are preamps that go in or near the bass itself, before it reaches the bass amp.

    We need to know which the poster is talking about.