Phantom power, in the context of professional audio equipment, is DC electric power equally applied to both signal wires in balanced microphone cables, forming a phantom circuit, to operate microphones that contain active electronic circuitry. It is best known as a convenient power source for condenser microphones,. Phantom powering was first used for copper wire-based since the introduction of the telephone in 1919. One such application in the telephone system was to provide a signalling. The International Electrotechnical Commission Standards Committee's "Multimedia systems – Guide to the recommended characteristics of analogue interfaces to achieve interoperability" (IEC 61938:2018) specifies parameters for microphone phantom. Some microphones offer a choice of internal battery powering or (external) phantom powering. In some such microphones, it is advisable to remove the internal batteries when phantom power is being used since batteries may corrode and leak chemicals. T-power, also known as A-B powering or T12, described in DIN 45595, is an alternative to phantom powering that is still widely used in the world of production film sound. Many mixers and recorders intended for that market have a T-power option. The method is. Phantom powering consists of a where direct current is applied equally through the two lines of a (in modern equipment, both pins 2 and 3 of an ). The supply voltage is referenced to the ground. Digital microphones complying with the standard may be provided with phantom power at 10 volts, impressed on both audio leads and ground. This supply can furnish up to 250 mA to digital microphones. A keyed variation of the usual Phantom power is also used in applications other than microphones: • • •.
