The Carl Martin Powerjack universal power supply for guitar effects employs switch-mode technology, allowing it to be used from 100V-240V. The Powerjack delivers 2000mA of stabilized 9V DC power at any voltage. Please follow all safety rules and regulations for the geographic region you are located in, and please consult your effects pedal manual before connecting the Powerjack to ensure correct voltage, polarity and plug type.
This is what they say
I have been using this for approx 1 month driving 3 effects + pitchblack tuner, with both acoustic & electric guitars. So far, NO perceptible noise (I get more from the pedals); I have not noticed it getting particularly warm; the connectors all fit tightly; the power cord itself is LONG (a good thing!).
This is the best power supply I have ever used! It powers my entire board with no problems! Have not had a problem yet with it! Highly Recommended!