How to Power Your Guitar Pedals: Batteries, Supplies, FAQ
If the power supply matches the current requirements (eg: 200mA power supply with a 200mA pedal) then you can use it as long as you don''t try to daisy chain more pedals with that supply. If the power supply has a higher current rating than the pedal (eg: 500mA power supply with a 200mA pedal) it will be perfectly fine to use.