be a DC current path between pin 1 of the microphone and the negative side of the 48-volt supply, if power is to reach the microphone's electronics. Lifting the ground, which is normally pin 1, breaks this path and disables the phantom power supply. There is a common belief that connecting a dynamic or ribbon microphone to a phantom-powered input will damage it. There are three possibilities for this damage to occur. If there is a fault in the cable, phantom power may damage some mics by applying a voltage across the output of the microphone. Equipment damage is also possible if a phantom-powered input connected to an unbalanced dynamic microphone or electronic musical instruments. The transient generated when a microphone is hot-plugged into an input with active phantom power can damage the microphone and possibly the preamp circuit of the input because not all pins of the microphone connector make contact at the same time, and there is an instant when current can flow to charge the capacitance of the cable from one side of the phantom-powered input and not the other. This is particularly a problem with long microphone cables. It is considered good practice to disable phantom power to devices that don't require it. Digital phantom power Digital microphones complying with the AES 42 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 XLR connector, the XLD connector, may be used to prevent accidental interchange of analog and digital devices. Other microphone powering techniques 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. Many older Sennheiser and Schoeps microphones use this powering method, although newer recorders and mixers are phasing out this option. Adapter barrels, and dedicated power supplies, are made to accommodate T powered microphones. There is often no audible difference between microphones featuring this method and microphones with P48 powering. In this scheme, 12volts is applied through 180ohm resistors between the microphone's "hot" terminal (XLR pin 2) and the microphone's "cold" terminal (XLR pin 3). This results in a 12-volt potential difference with significant current capability across