Phantom power how does it work

The idea here is that there is no flow of current to complete a circuit path that sends phantom power to the ground. The dynamic element is isolated from the ground, which means it will not sustain damage from properly applied phantom power.

Alternatively, dynamic mics will have an output transformer that will not pass any DC voltage to the mic element whatsoever. This is true of all ribbon microphones, which have very sensitive diaphragms.

Active microphones require power to function properly. Many of these microphones use phantom power but not all. So what types of microphones require phantom power and which do not? Moving-coil dynamic microphones are transducers that work on the principle of electromagnetic induction. Electromagnetic induction is a passive electrical process. There are also no active electrical components amplifiers, impedance converters, etc.

Ribbon mics typically do not have any active components, so they do not require any phantom power. Like the majority of miniature lavalier microphones, DC-biased electret microphones are certainly active but do not require phantom power. Rather, these mics work on a DC-bias voltage. Tube microphones are also active microphones but require more power than phantom power can provide.

Tube microphones require external power supply units to power their active components tubes and capsules properly. However, many electret mics require phantom power to function properly. These electret mics are generally studio-type microphones but range from consumer to professional-grade. Electret condenser microphone capsules are built with electret material in their design and are quasi-permanently charged.

The electret a portamento between electric and magnet material maintains a permanent charge across the condenser capsule. Therefore, external power like phantom power is not needed to polarize the capsule of electret microphones. True FET condenser microphones nearly all require phantom power. For the most part, true condenser microphones are studio-grade microphones, so phantom powering should be readily available in more situations where a true condenser is used.

Like the electret microphone, true condensers require phantom power to properly power their impedance converters FETs and other active electrical components. Unlike electret capsules, true condenser microphone capsules require an external polarizing voltage.

This voltage is supplied by phantom power as well. Active ribbon mics are passive transducers since they still convert sound to audio via electromagnetic induction. However, the low-level mic signal from the ribbon element is processed and amplified by active components before the audio signal is outputted from the microphone.

These active components impedance converters, amplifiers, etc. Phantom power is a positive voltage applied to both signal conductors of a balanced cable. Both conductors are fed through resistors of equal value:. The matched resistors must be matched within 0. Two specialized variants of phantom power have been developed for specialized applications:. A common example of a balanced non-XLR cable that passes phantom power is the typical TRS cable used in a studio patch bay.

Not only do they connect and disconnect more easily, but their size allows for more patching pathways in a smaller patch bay unit. These TRS patch cables do not generally plug directly into a phantom power source or directly into a microphone.

Rather, the patch cables are used in routing setups and will pass audio and phantom power from one point to another.

This reason is electrical shorting or the lack thereof. XLR cables are designed with 3 pins. The audio pins 2 and 3 are equal lengths, while the ground pin 1 is slightly longer. This means that when an XLR connector is connected, it is grounded before the audio and phantom power circuit is completed. Because pins 2 and 3 are equal lengths, they are connected simultaneously, and no shorting occurs.

So when connecting a TRS plug into a TRS jack, the tip of the plug first hits the sleeve, then the ring, then the tip of the jack. The ring of the plug follows, hitting the sleeve before connecting to the ring of the jack. However, when physically connecting or disconnecting these TRS jacks, we cause electrical shorts for example, when the tip connects to the ring.

These shorts may very well cause improper flow of phantom power, which can harm the microphone. However, it is possible for phantom power to damage microphones.

It is important to know how phantom power may negatively affect microphones, so we are better equipped to use P For example, some multi-channel mic preamps can only apply phantom power across multiple channels rather than on a per-channel basis.

Knowing whether a microphone can handle phantom power or not is essential in these situations. The situations that could potentially cause phantom power to damage a microphone include:. Electrical shorting, which was previously mentioned, will momentarily send the phantom power voltage up one audio conductor rather than both.

Among the most common is using a microphone pre-amp that supplies phantom power. This has the advantage of not only providing phantom power, but you also tend to have better quality inputs than many audio interfaces.

Another option is to use an external power supply. You can check with your mics manufacturer to see what product they recommend, and they may make a power supply specifically for your mic.

What is Phantom Power? Depending upon the design of the microphone, this power may be supplied by a battery, bus power from a computer, as well as several other methods, but quite commonly it is supplied by phantom power. Most modern mixing consoles provide phantom power, as do external audio interfaces, certain audio recorders and video cameras. Please note, though, that not all of these devices are guaranteed to provide phantom power. On most devices, phantom power can be turned on or off via switch, button or software.

In order for phantom power to work, a balanced microphone cable must be used. Condenser microphones such as Shure's KSM range all have active circuitry and require phantom power. The power can be provided by a battery located inside of the mic; an example is the Shure PG81 now discontinued that operates from a single AA battery. This method is referred to as phantom power. The worldwide standard for phantom power is 11 to 52 volts of DC typical studio mics run on 48v. However, some older mixers and cheaper audio interfaces may not have phantom power.

In this case, an external phantom power supply can be added between the condenser mic and the preamp.