Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

9V power supply?

  1. Jul 21, 2010 #1
    I need a power supply for my M-Audio Keystation 61es MIDI keyboard, and I think I might have one that will work for it.

    The user manual for the keyboard says this:
    But then their website is selling a 9v 500mA as the proper replacement:
    http://www.m-audio.com/products/en_us/PowerSupply9VDC500mA.html [Broken]

    And every other online retailer sells a 500mA supply as the replacement:

    A little bit confusing, but I have two laying around that might work, one is 9V 800mA and the other is 9V 300mA. Do you think either of these will be safe? If so, which one?

    Also, do the "input" specs on the supply matter much?
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jul 21, 2010 #2


    User Avatar
    Science Advisor
    Gold Member

    Welcome to Physics Forums.

    Looks like your keyboard requires up to 300 ma @ 9 volts. The output of these types of adapters indicate the maximum amount of current they can supply. So the 300mA one you have should work. What you want to make sure of is that the center connector terminal is the positive one (proper polarity).

    Yes the "input" specs matter. If you're in the US, mains voltages are 115vac. Other counties mains may be 230vac.
    Last edited by a moderator: May 4, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook