Phantom Power
Definition
A method of providing DC power (typically +48V) through an audio cable to devices that require external power, most commonly condenser microphones. The power is carried on the same XLR cable that carries the audio signal, eliminating the need for a separate power supply.
Context
Phantom power is one of the most common beginner questions in newbie-questions: “Do I need phantom power?” The answer depends on the microphone type:
- Condenser microphones (e.g., Neumann U87, AT2020, Rode NT1) — require phantom power to operate. Without it, they produce no signal.
- Dynamic microphones (e.g., Shure SM57, Shure SM7B, Electro-Voice RE20) — do not require phantom power and are unaffected by it being enabled.
- Ribbon microphones (e.g., Coles 4038, Royer Ribbon Mics) — most modern ribbons are unaffected, but some vintage ribbons can be damaged by phantom power. Check the manual.
Most audio interfaces and preamps include a phantom power switch (labeled “+48V”). Enable it when using condenser mics; it’s safe to leave on for dynamics but unnecessary.