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Description

Phantom power, in the context of professional audio equipment, is DC electric power transmitted through microphone cables to operate microphones that contain active electronic circuitry. It is best known as a convenient power source for condenser microphones, though many active direct boxes also use it.

FAQ

Can voltage fluctuations in the phantom power (PP) cause microphone hiss?

It's very unlikely that voltage fluctuations in the phantom power (PP) could cause hiss.

What are the 3 pins for phantom power?

There are three pins. Phantom power is connected to both pin 2 and pin 3 (but as long as your cable is not broken, simply use it).

X stands for ground (it is connected to the cable shield).

Pin 1 (X) = ground
Pin 2 (L) = + most commonly, or Left
Pin 3 (R) = - most commonly, or Right

Will phantom power damage dynamic microphones?

The risk is higher if it is an unbalanced connection. The Sound Reinforcement Handbook by Yamaha says something like this:

"In a phantom power system, the polarizing supply voltage is placed on both of the signal lines in a balanced connection, with the same polarity on each line. Dynamic microphones connected in a balanced system with a phantom power input are then protected from damage, theoretically, since the system results in a net zero DC potential across the coil. However, a dynamic mic connected unbalanced to a phantom power input may be destroyed."

In other words if you take a sm57 and plug it into a phantom powered mic pre using a normal balanced mic cable then you should be safe.

If you take an unbalanced mic and wire it with a xlr plug so you can connect it to that same input then you could fry the mic. In a balanced connection the 48 volts is running parallel down the 2 signal wires. With an unbalanced connection (2 conductors) you have 1 signal wire and ground and doing this is basically completing a circuit that sends 48volts directly to the mics voice coil.

What are the correct steps connecting a mic to phantom power

So the steps when connecting are:

1. Turn down those master faders.
2. Plug in mic.
3. Turn Phantom Power on.

and when disconnecting:

1. Turn down those master faders.
2. Turn Phantom Power off.
3. Unplug mic.

Can phantom power fry equipment?

If I were to use a condenser mic and send it to a compressor (XLR i/o) before going into a MOTU 896 HD with phantom power enabled on the mic input, would I damage the compressor? I was going to use an outboard phantom power adaptor or go directly from the mic to the MOTU and use a send/return loop for the compressor just to be on the safe side, but I thought I'd ask.