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AC adapters for stomp boxes

Discussion in 'Effects [BG]' started by ChaosGwar, Nov 11, 2002.

  1. I'm building a pedal board, and I don't know the DC input for effects pedals. I'm assuming 9 volts, considering they are powered by 9 volt batteries.

    I bought one from Radio Shack, but it doesn't work for any of my pedals. It's input is AC: 120V 60Hz 7W and it's output is DC: 9V 350mA

    It fits the pedal, but doesn't power it up. This is with the battery in or out.

    I don't have the maunal for the pedals anymore, if I ever had them to begin with.

    Or is there something better to use, other than a bunch of AC adapters and a power strip?
  2. Solid-Body

    Solid-Body Guest

    Nov 10, 2002
    Exiled to Australia
    Most likely, you've got the polarity wrong. On radio shack adapters, the tip can be installed two ways. There is usually a little arrow on the tip itself, and on the end of the cable there are two markings: + and -. Make the arrow point to + to make the center positive, and point to - to make center negative (ie, center-positive and center-negative). If you're not sure which one you need, try both. (Note: I have come across an effect pedal that you had to remove the battery to use the AC adapter, but this is rare.)

    As for using something better, unless your familiar with soldering and electrical work, several AC adapters should be used. If you feel like soldering, you can connect multiple tips to a single AC adapter, as long as the sum of all the mA ratings on the effect pedals connected don't exceed the mA rating on the AC adapter itself.

    I'm suprised you read this far! :)

    Good luck!
  3. mikeboth

    mikeboth The last thing you'll ever see

    Jun 14, 2002
    Tallinn, Estonia
    Operator: prophecysound systems
    What pedals do you have? Maybe then we can give you a better idea of what you need.

  4. gfab333


    Mar 22, 2000
    Honolulu, Hawaii
    I use this Signal Flex AC / DC power converter unit. It has the capacity for 5 pedals and only cost $35 at a local music store.

  5. chris h

    chris h Guest

    Jun 16, 2002
    Oxford, England
    yep, im using signalflex aswell now. sorry to deviate slightly, but does anyone know if it is possible to convert a 9vdc barrel plug to a positive tip ac plug (looks like a small headphone jack found on walkman headphones). because i want to use my q-tron without a seperate power source. (everything else is powered by the signalflex).

  6. BryanB

    BryanB Moderator Staff Member Supporting Member

    Reversing the polarity should be easy. However you will likely not want to have mixed polarities coming from the same source. It could introduce noise. Switching from DC to AC would be pretty tricky.
  7. Tecx

    Tecx Radio Rock Leads To Sterility

    Jun 9, 2002
    Halifax, NS, Canada
    Nope - been there try'd that - try to build your own distributor...


    ps. It is actauly imposable to change a ac input to a dc (because all the resistors, and diods would be kantucky fried)
  8. Jim Dunlop has somehting called the DC Brick that will power pedals of both 9v and 18v persuasions. I love mine. It is the size of an MXR stompbox.
  9. Tecx

    Tecx Radio Rock Leads To Sterility

    Jun 9, 2002
    Halifax, NS, Canada
  10. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Supporting Member

    Mar 24, 2001
    visual sound has a tiny one that has a chain for four effets for about 15$. Same as Boss PSA. (I think PSA stand s for Piece of **** Adapter.)
  11. In regards to the Radio Shack power supplies mentioned above that have reversible plugs, I would refrain from experimenting with polarity. Check on the back of your stomp box and look for a line that has a + sign on one side and a - sign on the other side with a dot between them. The dot will be surrounded by a C. If the C is open toward the - sign, align the plug end of the power supply that connects to the equipment so that the tip indicator and the - are together. If the C is open toward the + sign, align the plug end so that the tip indicator and + are together. Also, you must make certain that the tip is the proper diameter for your equipment. There are numerous sizes, so if not correct, you may not be making contact. As far as using the Radio Shack power supply, I had an intersesting experience two nights ago. I hadn't taken my Boss power supply with me to our Thursday night Church Praise & Worship service, so I used the 9v Radio Shack power supply that I use for my keyboard at home. I hooked it to my Boss TU2 tuner and everything seemed OK, except that it indicated my Bass was tuned extremely sharp. I thought that odd to be that far off, but tuned down anyway. Everything looked to be in tune, but when we started to play, I immediately knew something was wrong. I unplugged the power supply from my tuner and continued on battery. Now the tuner said I was tuned way way flat. I retuned and then sounded OK. Today at practice, I made sure to take my Boss power supply and all was normal again. Has anyone else had that same experience?
  12. tinfoil


    Oct 20, 2002
    I see no reason why not. Find out what the center is on the Signal Flex and wire accordingly. I can't understand how it would introduce noise either, it's not like you are changing the unit electrically, just re-routing it a bit.

    (edit to fix quoting the wrong message)
  13. Marley's Ghost

    Marley's Ghost Gold Supporting Member

    Feb 9, 2002
    Tampa, FL
    I use the Boss PSA 120t with the extension cables. It powers my Boss TU2, CEB3 and my Ibanez SB7 :cool: Yo do need a pedal like the TU2 that has power in and out.
  14. KB

    KB Supporting Member

    Jan 13, 2000
    Chapel Hill, NC

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