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Polarity Question

Discussion in 'Effects [BG]' started by sean_w_mcgrath, Aug 11, 2005.

  1. sean_w_mcgrath

    sean_w_mcgrath does this forum name make me look fat?

    Ok, it seems like matching polarity between power supplies and pedals is a big issue. So my question is, is there a way to determine the proper polarity that your pedal requires? I have a Digitech pedal that does not mention polarity anywhere...manual, website, or on the pedal. And it seems like most pedals have this problem. Would it mention polarity on the inside of the pedal anywhere? Can you tell by looking at the adapter plug on the pedal??

    Also, what are your chances of damaging a pedal by using the wrong polarity?

    Anyone have any useful resources on this type of thing?

  2. tplyons


    Apr 6, 2003
    Madison, NJ
    By looking at the pedal, the symbols you will likely find are either:

    [​IMG] meaning Center Positive or tip positive

    [​IMG] Meaning Center Negative or tip negative

    Other than these symbols, unless its written out on the pedal somewhere, there is no way of really knowing without REALLY knowing your electronics.

    If you use the wrong polarity... worst case scenario is:

    But it could end up in little more than fried compoenents.

    What pedal was it?
  3. syciprider

    syciprider Banned

    May 27, 2005
    Inland Empire
    Digitech, Danelectro, Voodoo Lab, MXR (and presumably Dunlop) and many other 9v pedals use what most ppl call the Boss PS120 style plug.

    I forget the size but it's negative tip with positive sleeve (2nd diagram in TP's post).
  4. tplyons


    Apr 6, 2003
    Madison, NJ
    2.1 mm

    However, Digitech MultiFX are different, IIRC.
  5. forgive my lack of electric/electronic expertise, but I've used a Boss PSA120 for my DigiTech BP80 with no problems whatsoever...

  6. tplyons


    Apr 6, 2003
    Madison, NJ
    Bobb, that's because of the same polarity, voltage, and an equal or higher rated current.

    However, I'm still not too sure about each individual Digitech product.