Stacked sweepable mid for jazz bass. Are they available?

Discussion in 'Basses [BG]' started by soaf, Dec 10, 2013.


  1. soaf

    soaf

    Joined:
    Jul 27, 2013
    I do not use the tone control on my jazz bass... I always run it wide open. I would like to replace it with a concentric parametric midrange stacked knob. I would like it to operate passively. Does anyone know if there are any in production? I believe it will be better to get the desired midrange I want at the guitar rather than at the amp, correct?
     
  2. bassgod0dmw

    bassgod0dmw Supporting Member

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    Mar 1, 2007
    Location:
    White Plains
    A passive preamp? No.

    There are plenty of preamps that fit into a J bass with mids & a mid freq selector. East J Retro comes to mind.
     
  3. TN WOODMAN

    TN WOODMAN

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    Smyrna, Tennessee.
    Good choice . Can't go wrong there. Love mine in a fretless jazz with Di Marzio Js and tapewounds .
     
  4. shaft311

    shaft311

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  6. soaf

    soaf

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    Jul 27, 2013
    Found one for guitar... Rothstein RG500D. A push/pull whereby pushed position acts as the regular tone control, and pull position acts as a cut/boost to mids with a notched center position. It is a passive unit. Not sure how well it will work with bass but maybe I can convince them to make a bass version for me! Certainbass also makes a mid contour control but mot sure if it just cuts mids or boosts as well. Anyone familiar with either of these units for bass?
     
  7. soaf

    soaf

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    Jul 27, 2013
    I should add... they are not sweepable. Still have not found a passive sweepable control.
     
  8. shaft311

    shaft311

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    Mt. Juliet, TN
    That's because power is required to fine-tune different frequencies such as you're wanting to do.

    The East unit is a drop-in. Has passive switch if you still need to be passive, but you're not going to find what you want if you have to stay passive.
     
  9. soaf

    soaf

    Joined:
    Jul 27, 2013
    Ok thanks. I guess I could live without the ability to dial into a particular frequency, as long as the product has a favorable midrange frequency boost. I am hoping the Rothstein works for bass. I have learnes that the Certainbass unit only cuts mids.
     
  10. shaft311

    shaft311

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    Another option that many people take advantage of is the number of DI box/preamp pedals. No mods to the bass, fits in a gig bag, and gives a great amount of adjustment of your passive tone. The Aguilar Tone Hammer comes to mind. There are many, but it's common, proven, and actually based on one of their on-board active bass preamps (OBP-3.)
     
  11. Hugh Jass

    Hugh Jass

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    Oct 10, 2008
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    Canada eh
    You can't use passive and boost in the same sentence. It's either on or cut. No boost.

    Edit: What you would be looking for is something where you could adjust which mid frequency you cut. Sorry, can't think of anything off hand but it would be cool!
     
  12. soaf

    soaf

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    Jul 27, 2013
    Apparently you can. See the passive Rothstein RG500D.
     
  13. Hugh Jass

    Hugh Jass

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    Canada eh
    This is a great idea too! Not very expensive and easily reversible (sell if you don't like).

    I absolutely love my Sansamp VT bass and actually use it as a pre-amp sometimes bypassing the one in my amp altogether. No sweepable mids but a ridiculous variety of actually usable tones.

    Not to dissuade you from sweepable mids, but I have them on my Spector and I'm forever faffing around with them whereas my Jazz I just run wide open pretty much all the time ;)
     
  14. RickBlair

    RickBlair

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    North Easton, Mass.
    From the Rothstein desciption it doesn't sound like it really boosts midtange - "When you turn the control from 5 to 10 you get a slightly thicker sound wtih a bit more of a midrangy honk to it."

    There is probably some low and high frequency cutting going on that brings out the mids more.

    As others have said, I don't think you will get a mid boost without an active circuit. EMG has some compact circuits that might work for you as well. The BQC is bass/treble and sweepable mids in 2 stacked controls. I crammed one into a SX Jazz bass by adding a side jack and routing a space for a battery under the pickguard.

    Rick B.
     
  15. Hugh Jass

    Hugh Jass

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    Oct 10, 2008
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    Canada eh
    That actually looks really cool! Easy to try and reverse and not too expensive either.

    If my jazz wasn't a stack knob I'd be tempted...

    As has been pointed out though, It doesn't boost anything, just variable cutting. With passive you only have the pickups native output and then the ability to filter out frequencies from there via the potentiometers and capacitors. Can't add anything without a battery.
     
  16. BioWeapon

    BioWeapon

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    Feb 16, 2013
    Location:
    Calgary, Alberta
    Sure...
    But consider this: a band pass filter+variable resistor (pot wired with pin 2&3 basically) can be put in place of a cap and pot. It can be run passive. It's a super simple circuit too, simple enough to be p2p.

    Difference between that and a preamp? Doesn't boost. Only cuts.

    Easy DIY project. Need diagrams? I have links (I'll have to pull them from my laptop tomorrow).
     
  17. soaf

    soaf

    Joined:
    Jul 27, 2013
    Just heard from Rothstein. It will merely add two nifty variable tonal filters when used for bass. Ok... so it.looks like I should be looking at something active. I would rather add a single pot to replace my tone pot, rather than going with a whole active control plate. It's really only midrange I am chasing. Any you can think of? A stacked-knob sweepable would be nice, or just a notched boost/cut in the desirable mid frequencies.
     
  18. bassgod0dmw

    bassgod0dmw Supporting Member

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    Location:
    White Plains
    Have you looked at the East? It's a drop in replacement and very simple to install. The only mid only systems that I know about are EMG and Pope, but I don't know how well they work for what you're wanting to do. You may find that you're missing something with just the mid control.

    Exactly. If I'm going to add some sort of mid tone shaping to a bass I'd prefer it to be able to boost.

    YMMV
     
  19. CoarseBass

    CoarseBass

    Joined:
    Dec 28, 2002
    There is a bass version of the Rothstein: http://www.guitar-mod.com/rg_passive.html

    Scroll all half way down.


    If you're handy, you can convert these to sweepable with another pot - though it may not be particularly useful. A mid sweep does not require power, as another poster indicated. Most sweepable mid preamps use a pot to passively vary resistance across a few components to create different resonances in an op amp based circuit, so your mid frequency center point changes.
     
  20. alembicbones

    alembicbones

    Joined:
    Nov 10, 2000
    Location:
    Seattle, WA
    Another vote for the East J Retro. I have a Marcus Retro in my MM 5 string. I can run the Bass and Treble flat, pan between the pickups as desired, use the passive tone control as desired, AND sweep and Boost/Cut the mids. Sounds like what you are trying to achieve.

    Bones
     

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