Phantom Power

[sien]

Does anyone know where the term phantom power comes from?

Hsien

[[Admin] danroth]

Originally Posted by sien

Does anyone know where the term phantom power comes from?

phantom power microphones need power to operate them.

rather than receiving that power through an obvious means (having a power cord that gets plugged into an electrical socket), they receive that power in a hidden ("phantom") way through the cable from the mixing board

[waynehoskins]

And the way it's placed on there (common-mode on the balanced pair, relative to the shield), it's invisible to devices that don't need it.

Both the hot and cold leads are biased up 48 volts relative to the shield, but since they're 0 volts from each other, to a transformer-balanced device like a passive DI or a dynamic microphone, it's as though there's nothing there at all. Devices that need power (active DIs and condenser microphones) can pick that voltage off and use it to power their preamps.

This is a huge improvement over the separate power supplies at the microphone or the special microphone cables with more wires in them for power.

[[Admin] danroth]

Originally Posted by waynehoskins

And the way it's placed on there (common-mode on the balanced pair, relative to the shield), it's invisible to devices that don't need it.

Yeah, that too.
(okay, so I left out the most important part)

[Bringit2DAMat]

has anyone ever heard of there being certain dynamic mics that are affected by phantom power. i know an engineer who it very strongly convinced that an audix d-6 will sustain damage overtime by it recieving phantom power and since our turns on phantom power 8 channels at a time it makes it difficult to keep phantom power from our dynamic mics

[stevegoad]

I have heard rumor that dynamic mics are damaged over long term use of phantom, but I have never seen it. I do, when I am using all dynamic mics, turn off the phantom. But I have one dynamic mic that is over 4o years old, and it works well, even though I run with phantom on most of the time in my studio set ups.

[waynehoskins]

Originally Posted by Bringit2DAMat

has anyone ever heard of there being certain dynamic mics that are affected by phantom power. i know an engineer who it very strongly convinced that an audix d-6 will sustain damage overtime by it recieving phantom power and since our turns on phantom power 8 channels at a time it makes it difficult to keep phantom power from our dynamic mics

I can't understand how it could. There's no voltage across the microphone element, though it does become 48 volts above the chassis. And in practice I haven't seen it either. Goodness, in years gone by consoles simply had phantom everywhere or nowhere, and many of them it was simply there all the time, not even a global switch.

[nbrakband]

Turning phantom power on while the sysem is on could be the last time you turn that system on.

[tedanderson]

The only issue that I have ever had with phantom power and dynamic mics is unplugging them while the phantom was activated and the channel was open. And in spite of the loud pop it created through the speakers, the mic itself remained unharmed.

The only thing that I could think that could remotely go wrong with a D-6 (and this is HIGHLY unlikely IMO) is that the larger diaphram and coil might pick up the phantom voltage inductively. But I put my D-112 on a phantom powered system and it has worked great for the last 9 years.

[extol!]

You do not want to phantom power a ribbon mic which is a type of dynamic mic. (Except for the one made by nady but all others will be damaged by phantom)

[[Director] drew ryan]

You can add the Royer R-120 series to the ribbon mics that use phantom power. They are also the best sounding Electric Guitar cabinet mic I have ever heard.

[fstroupe]

Since phantom power was used in telephones decades before microphones, I assume that the term was started then.