Bass Big Muff feedback WHEN TURNED OFF!!

Discussion in 'Effects [BG]' started by arcureo, Jan 27, 2014.


  1. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    Hi folks, this is really driving me crazy, so let me explain…
    I have an Electro Harmonix Bass Big Muff that I got specifically for its dry/effect feature. As you probably all know, it has two outputs, one for the distorted signal and one for the unaffected bass signal.
    I actually quote from its instructions page:
    "Direct Out Jack - is connected directly to the Input jack to allow access to your original bass signal. You can connect this jack to an amplifier or different effects chain."
    And that's exactly what I did!
    I kept two separate signal paths, and I joined them back just before the amp, with an EHX Switchblade, with both channels A and B, turned on.
    Like in the diagram below.

    [​IMG]

    When I have the Bass Big Muff on, no problem at all. Just a tad of grind below the other effects (I don't use much distortion).

    Bit if I turn the Big Muff OFF... ALL HELL BREAKS LOOSE!!!!
    A wild, howling, strange electronic feedback kicks in!!

    Kind of "WEEEEEAAOOOOOOOUUUUUURRRRRR!!!!"

    Un-usable, to say the least!


    What's the problem, here?
    Is it the Big Muff that has a bug or a defect, or is it a peculiar behavior of its own?
    I couldn't find anyone among my bass-playing friends who could lend me an identical pedal so I could check wether this working condition is just a glitch of my own stompbox or is typical of ALL the Bass Big Muff pedals!

    Anyone has any idea…?

    Cheers!
  2. bassgod0dmw

    bassgod0dmw Supporting Member

    Joined:
    Mar 1, 2007
    Location:
    White Plains
    Definitely not typical and there is something wrong.
  3. shenanigans

    shenanigans

    Joined:
    Sep 9, 2013
    Passive blending. The switchblade is allowing your signal to feedback into the BBM and then through your effects chain.

    To test:

    Switch bewteen A and B on the switchblade. The feedback should disappear.

    If you have an active mixer laying around somewhere, try running the two signals into two channels on that, the feedback should disappear.

    The solution is to get a mini mixer like a Nady MM141 or Wounded Paw Mini Mixer, or a dual looper like a Boss LS2 or Badger schism or the like.
  4. charlie monroe

    charlie monroe Supporting Member

    Joined:
    Feb 14, 2011
    Location:
    Buffalo, NY
    Wouldn't it be easier to use the switch pedal as the switch, and not the muff?

    Leave the muff on all the time. Use the switchblade to select dry only or dry/effect signal.
  5. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    Yep, I used an LS2, in the end, but I wanted to use it at the very beginning of my signal chain, to switch between two basses.
    I know I can do the same thing with the Switchblade, and I actually do, but the LS2 has input level controls that are soooo much more useful in case of instruments with different output levels… well… whatever. Thanks a lot for the explanation! ;)
  6. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    IT….

    COULD…

    WORK!!!!

    [​IMG]


    (The only downside is that I'd have to be VERY careful not to accidentally switch the Big Muff off, or I'll really risk throwing my speakers into orbit!!! But it's worth a try)
  7. shenanigans

    shenanigans

    Joined:
    Sep 9, 2013
    1 other thing you can try doing is putting a buffer in the empty chain. You're still passive blending, but you should get rid of the feedback loop.
  8. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    Uhmmm, interesting… a buffer such as…?
    Can you give me some pointers?

    Thanks! 'preciate it!! :cool:
  9. BassMonstrum

    BassMonstrum

    Joined:
    Mar 7, 2008
    No one can tame the muff!

    Seriously though, get it checked.
  10. shenanigans

    shenanigans

    Joined:
    Sep 9, 2013
    A boost pedal, an EQ, a non true bypass tuner, any Boss pedal that isn't engaged. Basically any active circuitry that doesn't interfere with your tone should do it.
  11. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    Interesting! I'm definitely gonna try that! I have an old Ibanez BE10 that's been collecting dust… let's see if I can use it that way!
    Thanks a lot! :)
  12. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    Well… both solutions worked fine! :hyper:
    (Shenanigans' and Charlie Monroe's)
    Thanks for all your help, guys! :D:cool:
  13. Mosfed

    Mosfed The mighty mighty Supporting Member

    Joined:
    Apr 21, 2013
    Location:
    On the Mont Blanc
    Definitely get the pedal checked. But I am happy you found a fix in the meantime.
  14. shenanigans

    shenanigans

    Joined:
    Sep 9, 2013
    I honestly don't think there is anything wrong with his pedal other than EHX cuts corners with their design. You can't have a true bypass pedal with multiple outputs unless you make a design sacrifice, and I think it's clear where that design sacrifice is.
  15. arcureo

    arcureo

    Joined:
    Mar 7, 2007
    Location:
    Padova, Italy
    Yeah, I think the "passive blending" phenomenon is a valid explanation, but I also posted this similar question in the EHX forum, maybe if there's actually something wrong, they can tell me!
    Anyway at least now the problem has been sidestepped, so YAY! :D

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