We have just installed a new sound system at my church. As part of this we are using a DI box to connect in a keyboard. The DI box needs power either from Phantom Power or a 9V battery. Our sound desk is capable of doing 48v Phantom power. Is there any advantage of using one or the other?
I would use the sound desk. It's always on & you won't need to swap it out every couple weeks. Hopefully... :)
Drawbacks? You may need to use a ground lift on your keyboard if there's hum. For a relatively stationary system like a church...no need to fiddle with batteries.