Should I turn on phantom power? That’s a great question. One that seems a bit perplexing when you have no idea what phantom power is, or what it does. It’s the very same question I asked myself when I first faced this dilemma. Don’t worry though, I’ve got you covered. In this article I’m going to answer all of the questions you have about phantom power to clear up the confusion. First, let’s look at what phantom power is.
Should I Turn on Phantom Power?
You should only turn on phantom power for devices that are designed for its use. The most common requirement for it in home recording studios is to power condenser microphones, which require 48 volts. Without phantom power the active components will not work. Another common use for phantom is for DI boxes.
What is Phantom Power?
Interestingly enough, the word phantom -which we normally associate with spirits and apparitions- is used for phantom power because the power source is invisible. Ooooo, spooky… How so? This is because it flows through the same cord as the audio signal does. So, despite sounding like some kind of powerful apparition, it’s is much less scary than that. Phantom power is a positive voltage of 48 volts that runs on pins number 2 and 3 of a balanced XLR cable, which we use for microphones.
What Does Phantom Power Do?
If you have an audio interface, or mixing desk, you’re probably already aware of a button that says 48V. By pressing this button, you enable phantom power and provide the necessary DC current required for condenser microphones, without the need of bulky power supplies.
Why Do Condenser Mics Need Phantom Power?
Without getting too technical, condenser microphones are active and require an external power source. Dynamic microphones on the other hand are passive and do not require any extra power. The active components in a condenser mic which are the circuits, internal preamps, and impedance converters all need phantom power to operate efficiently. Phantom power also polarises condenser microphones’ capsules. You can read all about condenser microphones in my full guide.
When Should You Not Use Phantom Power?
As discussed earlier, you do not need phantom power for dynamic microphones. It won’t damage them and they will work just fine with it enabled, but there is no need at all. Also, never use phantom power with ribbon microphones. They are far too sensitive and doing so can damage them beyond repair. Do you need phantom power for guitar? No, guitars don’t require phantom power, they can be powered sufficiently enough with a preamp, like those are inbuilt into audio interfaces.
You should only use phantom power for condenser microphones. The other time you may use it, is for a DI (Direct Injection) box. Sound engineers use DI boxes to convert an unbalanced signal (high impedance. to a balanced signal (low impedance). For example, if you want to plug a guitar directly into a mixing desk.
Should You Turn on Phantom Power Before Plugging in a Mic?
No, it’s best to plug in your microphone first and then turn on phantom power. Not only does the reduce the chance of damaging the microphone, it also prevents audible pops from occurring if the speakers are turned up loudly.
Now You Know All About Phantom Power
At first, it may seem a scary pressing a button with 48 volts of invisible ghost power! But now you know what phantom power is, what it does, why it’s needed, and when you should use it. Just remember that the most common uses are for condenser microphones and DI boxes. Other than that, you shouldn’t need to press that button and waste any unnecessary use of electricity in your home. I hope this article was helpful. If you have any comments or questions then please write them down below. I’d be more than happy to help you out.
Chris (Chris’s Sound Lab)