The Phantom power supply was born in 1966 after Neumann, a renowned German manufacturer of microphones, presented a new series of microphones on Norwegian radio.
For compatibility reasons, the Norwegian radio required that these microphones work with an easily obtainable external power supply.
Due to the limited number of hours of the day in the winter months, the Studios used an alternative lighting system provided by a 48 Volt central power supply. This consequently became the voltage used to power the microphones.
Phantom + 48V power, which later became a standard, is available today on most mixers, amplifiers, recorders and other audio equipment.
Phantom power is, in the simplest terms, an external source for condenser microphones which need it in order to function. Phantom power is obtained by transferring DC DC power to the microphone via the 3-pin XLR connector and a microphone cable.
Although this term over time has been distorted and sometimes used improperly referring to any external power source, Phantom power is defined with the standard DIN 45 596 or IEC 268–15A
How Phantom Power Works
In a balanced connection microphone (with a 3-pin connector) the second pin is the positive, the third pin is the negative and both use the first pin as ground. This applies to condenser microphones, as these microphones do not produce electric current, unlike dynamic or ribbon microphones. A condenser microphone only modifies the voltage applied to the condenser electrodes following the trend of the sound waves that meet the microphone diaphragm.
Since condenser microphones do not create an electrical signal, it is necessary to have an external phantom power supply. One of the reasons why this external power supply method is so practical is that the dynamic or ribbon microphones connected to this power supply are not damaged. It is therefore possible to connect all three types of microphone with this power supply without worrying about the integrity of the microphone.
Types of Phantom power supply
Although the most common type of Phantom power supply is the 48 Volt (P48) one, there are two other types available: 12 Volt (P12) and 24 Volt (P24) less common than the P48 and mainly used in battery powered equipment . A common problem with battery powered equipment is that in some cases they cannot provide enough energy. There are other types of Phantom power supply that are rarely used, but P48, P24 and P12 are standard.
Problems with Phantom Power
It is safe enough to use phantom power as long as the right equipment is used with it. An unbalanced connection microphone, a high impedance microphone, or microphones not designed to be connected to Phantom power can cause damage to the power source and, rarely, to the microphone itself. Outside of these cases, phantom power can be used safely without distorting or deteriorating the sound quality.