Yamaha DTXpress/DTXplorer/DTXtreme

The transformer in the power adapter will always draw a small amount 
of current, even when the module is off. If you unplug the adapter 
when it's not in use it will last a lot longer and your electricity 
bill will be smaller. (It's actually a really small amount of watts 
but if you have alot of power adapters in your house that are not in 
use every day it makes a difference at the end of the year)

G