pearlnpaiste
New member
what is phantom power, how does it work, and where is it used.
It's a power source for condensor microphones. 48 volts positive is sent through both conductors of the mic cable. The reason it's called phantom is because dynamic mics ignore it.pearlnpaiste said:what is phantom power, how does it work, and where is it used.
You're probably right.dkelley said:I always thought that the reason it's called phantom is because it runs through the signal wires for your mic without requiring any additional wiring.
dkelley said:I always thought that the reason it's called phantom is because it runs through the signal wires for your mic without requiring any additional wiring.
By the way, if you use a ribbon mic it will probably blow up with phantom power connected, so it has to be able to be turned off if you want to use a ribbon mic.
bennychico11 said:nah, it's because other microphones ignore it. electricity can run through anything that's a conductor...in either direction too. If you took a microphone cable and stuck it in a wall outlet, it'd still shock the hell out of you without needing any rewiring. But we wouldn't call that phantom power, would we?
bennychico11 said:this is an old myth, that is used pretty much for precaution nowadays. Older ribbons were wired differently, so yes, they could become damaged or stretched (not "blown up"). The only way it could probably harm your newer microphones (which is probably what you have, unless you're lucky enough to own a vintage mic) is if there is some sort of miswiring in the microphone in your studio. Here's a link from Royer Labs explaining these circumstances:
http://www.royerlabs.com/phantom.html
But yes, it's a safe precaution to follow....but so is not using ground lifts in your gear, and people still do that.
Will phantom power damage dynamic or ribbon mics?
When you switch on phantom power in some mixers, phantom is applied to all the mic inputs at once. What will happen if you plug a dynamic or ribbon mic into one of those inputs? Will it be damaged by the phantom powering?
Not if the mic has a balanced output, and is wired correctly. Even if the mic is a dynamic or ribbon type, phantom will not hurt the mic.
Phantom powering applies a positive voltage to pins 2 and 3 in the mic, and the ground of the phantom supply is connected to pin 1. In a condenser mic, pins 2 and 3 are wired to the circuitry inside the mic. Phantom current entering pins 2 and 3 goes through the mic circuit, then exits out pin 1 and returns to the supply ground.
In a dynamic mic or ribbon mic, pins 2 and 3 are wired to the mic’s voice coil or ribbon. Normally, the coil or ribbon is floating from the pin 1 ground. So the circuit loop to and from the phantom supply is incomplete. No current can flow through the mic’s voice coil or ribbon if you apply phantom power. Result: no damage.
On the other hand, if one end of the voice coil or ribbon is accidentally shorted to ground inside the mic, several milliamps of current from the phantom supply will flow through the voice coil or ribbon back to the ground of the supply. This current can deform the ribbon or immobilize the mic diaphragm.
In short, if the mic has a balanced output in which the voice coil or ribbon is NOT connected to mic ground, phantom will not damage the mic. If the mic has an unbalanced output because the voice coil or ribbon IS shorted to mic ground, phantom could damage the mic.
Hope this helps...
Bruce Bartlett
Mic engineer