What's Phantom Power?

Well, it goes like this...

ooooooOOOOoooooOOOoooOOOOOOOooooooopowwerrrrrrr.........

Or maybe not.

Okay, kidding aside. Phantom power is a 48 Volt DC voltage carried by the balanced microphone cable. Certain mics, such as the Beta 87 and the SM-81, require DC power to operate. The phantom power is a convenient way to power these mics without having to have separate power supplies or internal batteries. The 48V switch at the top of the X8 channel row turns this power on and off. You can use a mic that doesn't require phantom power (like an SM-57) and leave the phantom power on and it won't hurt a thing. The SM-57 will simply ignore it. However, there are circumstances where there must be no phantom power on the line. Our Behringer stage sub-mixer outputs would be a good example. If you have 48V enabled while connected to that sub-mixer, your signal will disappear.

If a mic doesn't work, the 48 Volt switch is the first thing to check. If you must turn it on, be sure and mute the channel or you will be rewarded with an obnoxious (and possibly damaging) thump.

Be aware that a patch cable connected to the soundboard side of the patch bay but not connected to the stage side will have 48 Volts on the exposed plug. You may see a slight spark if you then plug the stage side in. As a matter of good practice, if you have to change a patch on the fly, mute the appropriate channels, disconnect the board side first, then the stage side. Reconnect the stage side first, then the board side. This will avoid exposing the 48 Volt power.

Incidentally, this is why we cannot use wired mics anywhere near the baptistry because 48 Volts and water creates a genuine safety hazard.

Jim K.