PHANTOM POWER BASICS: Microphones/Preamps

Certain microphones (and other devices) have onboard electronics that require electricity; "Phantom Power" is a very common method of powering these devices. It's called "phantom" power because it works "invisibly" by sending DC power back to the device using the same microphone or instrument cable that carries the audio signal from it. One cable, two jobs!

Phantom Power is best known (and most often used) as a power source for condenser microphones (like our K&K Sound Golden Bullet Mics and the DPA 4099 Bass Mic), though many active DI boxes and preamplifiers can also use it to supply their operating power (like the K&K Pure XLR Preamp or the Fishman Pro EQ Platinum Bass, among others). As you can see in the image to the right, the same cable carries the audio signal FROM the preamplifer, while the mixing board sends DC power TO the preamplifier, all without adding noise to the signal. This makes it possible to use the preamplifier without draining the battery or using an external power supply.

VOLTAGE IS IMPORTANT: There are two general types of phantom power microphones: the more common type that typically uses XLR (aka microphone) connectors and requires between 12-48 volts, and the type ordinarily used with "mini" condenser mics that uses approximately 9 volts in parallel with the signal cable. The 9v type is usually terminated with ¼" phone plugs rather than an XLR. Because they use different voltage levels, they are not interchangeable.

Phantom power supplies are often built into mixing consoles, microphone preamps and similar equipment. Alternatively, a separate dedicated unit can be inserted into the microphone circuit as required. In the case of the Golden Bullet Microphone, the mic comes with its own dedicated "power box" which is operated by a 9v battery and passes the audio through to your amplifier or mixing board.

Though a large variety of units can either supply or use "phantom power," the manner in which they do so (and the voltages they use) can vary, and one must exercise care to ensure that the individual pieces of equipment they are using are compatible with each other. For instance, the K&K miniature condensers (Golden Bullet/Trinity mics and systems) use a 9v current sent through a standard ¼" instrument cable. Yet the phantom power used to power the DPA 4099 Bass Microphone, Fishman Pro-EQ Platinum Bass or the K&K Pure XLR use the common 12v-48v "standard" used by most studio equipment; it is sent through a three-conductor XLR (microphone) cable, usually powered by a recording mixer or PA board.

It's usually easy to determine which units are compatible; in our product descriptions, we include the specs for voltage when a unit has phantom power capabilities or needs. Many of our product pages also have links to manufacturer instructions and product manuals, and these will cover their phantom power specifications in more detail.