The problem with most wall-wart adapters is that they aren't regulated, some straying up to 13 volts or so, causing hum and horrible tone—enter the Fulltone FPS-1 (200 mA.) regulated adapter. It's dead quiet and exactly 9 volts no matter what your wall AC is putting out. This adapter has the standard 2.1mm x 5.5mm end with a negative center pin and will work with most effects pedal from BOSS, Ibanez, and other pedals from Fulltone that include the FD2, OCD, Bassdrive, UltOct, '70, and CF-1.