rat power adaptor - equivalent to center pin - or +?

Discussion in 'Effects, Pedals, Strings & Things' started by samhambone, Jan 24, 2008.


  1. samhambone

    samhambone Member

    Messages:
    651
    Joined:
    Nov 22, 2007
    i want to swap out the existing power jack for a boss style jack that's compatible w/ my dunlop brick power supply - however, i don't want to annihilate my pedal. can the existing jack be swapped for a boss style and is the pedal set-up to accept center pin negative?
    thanks
     
  2. jb1911

    jb1911 Member

    Messages:
    5,192
    Joined:
    Jan 11, 2007
    Location:
    Chicago
    The Rat is center pos, so you'll have to swap them when you go to the Boss jack.
     
  3. samhambone

    samhambone Member

    Messages:
    651
    Joined:
    Nov 22, 2007
    thanks for the info - just to clarify -
    do you mean just reverse the wires - what is positive in the rat connect to negative on the new jack? negative in the rat to positive in the new jack?
     
  4. stinkfoot

    stinkfoot Member

    Messages:
    5,914
    Joined:
    Jun 20, 2004
    Location:
    Uppsala, Sweden
    Negative is negative, and positive is positive. Replacing the jack doesn't change that :D

    The stock RAT jack accepts a 1/8" phone plug, with the positive carried on the tip. The Boss-type jack accepts a 2.1mm barrel type plug, with the positive carried on the outside of the barrel (center negative).

    [​IMG]

    /Andreas
     
  5. jb1911

    jb1911 Member

    Messages:
    5,192
    Joined:
    Jan 11, 2007
    Location:
    Chicago
    What Mr. Brougamadrosis said.
     
  6. SonicVI

    SonicVI Member

    Messages:
    1,607
    Joined:
    Dec 26, 2007
    Location:
    Houston, TX
    Just get an adapter cable.
     
  7. Grap

    Grap Member

    Messages:
    1,107
    Joined:
    Nov 3, 2003
    Location:
    Kuala Lumpur, Malaysia
    Plus. you may get some hum if you have the RAT on the same daisy chain as pedals that take a Boss style supply because of the way the devices are earthed: -ve earth vs a +ve earth.

    I get some very strange low-level noises out of my Korg G4 when I kick in my RAT. Not noticable at a gig though, fortunately.
     
  8. stinkfoot

    stinkfoot Member

    Messages:
    5,914
    Joined:
    Jun 20, 2004
    Location:
    Uppsala, Sweden
    Hold on - a RAT is negative ground, just like any regular Boss or Ibanez pedal. The only difference is in the type of jack used.

    If you mix positive and negative ground pedals in the same daisy chain, you won't get any hum - you'll get nothing at all, as the power shorts out completely :D But positive ground pedals are quite rare beasts - it's mostly germanium fuzz pedals, octavias and some rangemaster-type circuits - so most of us will never come across one.

    /Andreas
     
  9. jb1911

    jb1911 Member

    Messages:
    5,192
    Joined:
    Jan 11, 2007
    Location:
    Chicago
    You are correct, sir!
     
  10. sandman

    sandman Member

    Messages:
    1,990
    Joined:
    Aug 14, 2005
    I think you're all confusing reverse polarity and positive ground? Stinkfoot?
     
  11. sandman

    sandman Member

    Messages:
    1,990
    Joined:
    Aug 14, 2005
    Correct me if I'm wrong Rat(or that one at least, older EHX, Klon) is negative ground but the polarity is reversed - thus the 'male' plug with 'positive tip'.
    No problem daisy-chaining them with Boss/Ibanez-like stuff.

    Some fuzzes (Fulltone '69 perhaps) are both positive ground AND reverse polarity - but with 'Boss' looking jacks wired in reverse?
    You can't daisy-chain these together with Boss type stuff.

    Right????????
     
  12. stinkfoot

    stinkfoot Member

    Messages:
    5,914
    Joined:
    Jun 20, 2004
    Location:
    Uppsala, Sweden
    The polarity on the RAT, older EHX etc isn't reversed per se - they use a different jack/plug type, so relating their polarity to the Boss-type jacks/plugs will only confuse things. Boss is center negative, RAT etc is tip positive. One isn't the reverse of the other, as they are two different jack types.

    As you noted, some pedals (the '69 indeed, among others) are positive ground. This means that the battery positive goes to ground, instead of feeding the circuit. The adapter jack can be wired either way - even though most of them are wired center positive, to allow for the battery negative to be switched out of the circuit when the adapter is connected. Regardless of how the jack is wired, you need a separate power source for these pedals (with correctly wired plugs, of course, to match the pedals in question).

    /Andreas
     
  13. sandman

    sandman Member

    Messages:
    1,990
    Joined:
    Aug 14, 2005
    Thanks!!!
     
  14. 89strat

    89strat Member

    Messages:
    1,074
    Joined:
    Jan 6, 2006
    If you're using the brick, doesn't it come with a cable to attach to your rat?
     
  15. jb1911

    jb1911 Member

    Messages:
    5,192
    Joined:
    Jan 11, 2007
    Location:
    Chicago
    Yes, it does.
     

Share This Page