plugging a active bass into the passive input on the amp and vice versa

Discussion in 'Pickups & Electronics [BG]' started by adobass, Mar 2, 2010.


  1. adobass

    adobass

    Joined:
    Mar 2, 2010
    hey, ppl

    i have two basses

    1.fender highway jazz bass (usa) and it has passive electronics
    2. marcus miller signature (japan) it has active and passive electronics (controlled by a switch)

    i just want to know if i plug my highway jazz into the active input on the amp does it damage the pre-amp in the bass? or if i plug in my MM signature bass in active mode into the passive input on the pre-amp does that damage the pre-amp in the bass?

    please help me out thanks :)
  2. line6man

    line6man

    Joined:
    Jun 20, 2008
    Location:
    Close to Los Angeles, CA
    It won't do any damage.

    The active input simply means that the input is padded for especially hot signals so that it won't distort.

    If you find your bass to be too loud for the passive input, try the active input instead.
  3. SamTheButcher

    SamTheButcher Yis, actually.

    Joined:
    Sep 25, 2004
    Location:
    Charlotte NC
    Plugging the passive bass into the active jack will hurt nothing, but you'll probably have to increase the master volume. Plugging the active bass into the passive input should be fine, but only as long as you don't crank the levels onboard the bass. If you dime the bass' preamp into the passive amp jack, depending on what amp it is, you could damage the amps input.
    I usually run a passsive Jazz or P into a SansAmp DI and Tech 21 compressor (all 9v, which basically acts as an active preamp), then into the active input on my amp; but we use a drum machine thru my amp alot at practice, and at these times I run the drums thru the active jack, and the sansamp DI / compressor thru the passive jack. Never had a problem. Just keep an eye on the input levels.

    Of course....YMMV.
  4. casbonano

    casbonano

    Joined:
    Aug 29, 2009
    Location:
    virginia beach
    i know this is an old thread, but for the sake of any one who (do i dare say it?) uses the search function looking for info on this very topic;

    i'm running a a fender standard (passive) jazz through a mxr bass di + and then into an amp.

    i've found that i prefer to plug into the passive input of the amp because if i go into bypass mode on the mxr m80 and i am jacked into the active jack my volume level drops. as long as i am in the passive jack, all is well either way.

    also, i find that that the sound is much better through the mxr when the the eq/distortion channels are on (in other words not in bypass). its riche, fuller.

    HOWEVER.

    as i was typing this i got the idea to put the mxr through the fx loop on the back of the amp and then plug the bass into the passive input on the amp. this seems to work best of all and is even richer than plugging the bass>di>passive input on the amp. I imagine you can still go straight to board from the mxr, right? so have i just in essence added an xlr out to my ampeg BA110 combo amp? anyone?
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  6. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    yeah, you're now going through two preamps in a row, the internal one then the MXR. you can use the MXR's xlr out to get all of that into the board.

    also, for kicks try skipping the preamp of the bass amp entirely! plug the bass right into the MXR, then run that straight into the effects return of the amp; you're now just accessing the power section of the amp, bypassing the front controls.

    (and "active" vs. "passive" inputs is kind of a misnomer; it should just be "0dB" vs "-6dB", or "full signal" vs. "less signal"; that's all it is.)
  7. casbonano

    casbonano

    Joined:
    Aug 29, 2009
    Location:
    virginia beach
    hey thanks! it's much louder this way and just as rich if not ricer, so obviously i'm going to have to be mindful of my volume. this kinda simplifies everything since now i only have the MXR EQ to take into consideration.

    Appreciate that!
  8. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    if there's a master volume on the amp, it might still be active even if you bypass the preamp, so check that too.

    this is just how i use my sansamp DI, which is the same idea as the MXR (the MXR is likely a sansamp copy); the box becomes my bass preamp, with the 1/4" out going to a regular PA power amp to run my bass speakers for on stage, and the XLR going to the PA.
  9. casbonano

    casbonano

    Joined:
    Aug 29, 2009
    Location:
    virginia beach
    So if I were to use any kind of fx pedal/box where in the chain would I put it? Before the in order to get it to the pa, right?
  10. Jazz Ad

    Jazz Ad Mi la ré sol Gold Supporting Member

    Joined:
    Mar 16, 2002
    Location:
    Reims, Champagne, France
    Not in any way, regardless of how you may push any preamp, you won't damage input stages. You may get a distorted tone but that's about it.
  11. mystic38

    mystic38

    Joined:
    Dec 4, 2012
    Location:
    Mystic CT
    +1

    There is usually an input impedance difference between active and passive inputs on an amp, but tbh, i doubt that anyone will really notice an audible difference.. but, now that you know its there, you will fake yourself into noticing something :)

  12. eddododo

    eddododo Supporting Member

    Joined:
    Apr 7, 2010
    Actually, at least on my amps/amps ive researched, the input impedances are reported as identical. I think its usually a slight difference in gain, which explains why the 'active' input is a decent way to eliminate a little signal noise
  13. SGD Lutherie

    SGD Lutherie Banned

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    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    I always plug my active basses into the passive input. I think it sounds better.
  14. walterw

    walterw Supportive Fender Gold Supporting Member

    Joined:
    Feb 20, 2009
    yeah, in front of the MXR preamp.
  15. SGD Lutherie

    SGD Lutherie Banned

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    Aug 21, 2008
    Location:
    Bloomfield, NJ
    Disclosures:
    Owner, SGD Music Products
    The active input has a resistor to pad the signal down a bit. I usually find it's too much resistance for my taste, and it makes the tone kind of dull. Even though the two inputs have the same impedance, the series or parallel resistance will alter the impedance.
  16. eddododo

    eddododo Supporting Member

    Joined:
    Apr 7, 2010
    I love talkbass
    Thanks for the knowledge
  17. casbonano

    casbonano

    Joined:
    Aug 29, 2009
    Location:
    virginia beach
    Yeah. Thanks to everyone for the input. Learned somethings.

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