How can i get phantom power

Condenser microphones made in the s, s, and s required a special power supply to operate. This power supply would often be located quite near the microphone and was usually large, heavy, and cumbersome. In the s, work began on a new powering concept that would eliminate the need for a separate power supply. Schoeps and Neumann German microphone manufacturers were leaders in this development.

Eventually, a new condenser mic powering standard emerged. The DC power to operate the condenser mic was provided by the mixing board and delivered via the mic cable; eliminating the need for an external power supply.

And what does one call a power supply that is working, but invisible? It is a phantom power supply! Read on for a simple explanation Phantom power is used in connection with microphones although there are some other devices that also use phantom power.

To understand how it works, you need to understand a little bit about the mechanics of how a microphone works. The majority of microphones can be divided into two categories: dynamic microphones, and condenser microphones.

Dynamic microphones are the simplest type of microphone. Put simply, when the air around a dynamic microphone vibrates due to sound, it causes a diaphragm mounted at the end of the microphone to vibrate, too.

This is attached to a coil of wire, which is attached to a transducer. This converts the vibrations into an electrical signal, which is transmitted down the cable to the microphone pre-amp, where it will eventually be converted back to sound via another transducer. Dynamic microphones are not the most sensitive microphones around. Condenser microphones, however, are far more sensitive. Still, in some routing situations, phantom power may be sent through a patch bay via TRS cables before reaching the microphone.

XLR cables are wired as follows:. Basically, the audio from the microphone capsule is sent down pins 2 and 3 relative to pin 1 of the XLR cable. Audio signals are AC, and pin 2 carries a positive polarity mic signal, while pin 3 carries a flipped, negative polarity version of the same signal. So the audio signals on pins 2 and 3 are completely out-of-phase with each other. At the balanced mic input preamp, interface, mixer, etc.

This means that the resulting audio signal is effectively the sum of two in-phase audio signals. This wiring setup allows for common-mode rejection CMR. CMR is the cancellation of similar signals on pins 2 and 3. For example, any noise or electromagnetic interference in the cable will equally affect pins 2 and 3. Similarly, phantom power applies the same 48 volts DC on both pins 2 and 3. What does this have to do with phantom power? Well, since phantom power is sent through balanced cables, it does not affect the sound of the audio, nor does it add noise to the signal!

So we know that phantom power is a DC voltage on the audio wires of a balanced cable pins 2 and 3 of an XLR. This blocking can be accomplished with an output transformer, as is the case with passive ribbon microphones.

Moving-coil dynamic microphones sometimes do not have output transformers. Their capsules, however, will typically not be affected negatively by phantom power. Microphones that require phantom power to function properly are designed with the appropriate circuitry to send phantom power where it is required.

Essentially the mics that need phantom power will accept it, and those that do not will ignore it. With those microphones that need it, phantom power is used for the following functions:.

Some may only require 9 V DC, while others may even require more than the full Whatever the required voltage is, the microphone will be designed with appropriate circuits to step up or step down the phantom power for proper powering. Some lower-end and consumer-grade interfaces, consoles, or other power supplies will not supply the full 48 volts in an effort to reduce costs.

A lower phantom power voltage may negatively affect the performance of the microphone. Alternatively, use a voltmeter to check the voltage across pins 2 and 1 and pins 3 and 1. High-end audio equipment P48 sources mixing consoles, audio interfaces, etc.

Other sources may have a single switch for all channels or a few switches that control multiple channels each. As mentioned above, phantom power originates from the power main. There are multiple sources that effectively produce phantom power.

The 2 main phantom power sources are:. Because nearly all microphones are plugged into mic preamplifiers, including a phantom power circuit in the mic input makes perfect sense. A great example of an inexpensive audio interface is the Focusrite Scarlett 2i2 link to check the price on Amazon :. Some low-quality preamps will supply slightly less. There are also standalone phantom power supply units on the market.

However, standalone units are required if we want to plug a phantom-powered mic into an input that does not supply the correct phantom power or any phantom power, for that matter.

Microphone circuits range from very simple with passive dynamic mics to incredibly complicated with some condenser microphones. This is especially true if we do not understand electrical circuit theory. An important safety measure with phantom power is only to switch it on once the microphone is connected to the source.

This will help prevent electrical shorting and protect the internal circuitry of the microphone in question. Here is a simplified diagram of a phantom power source and the mic input to the right supplying phantom power to a condenser microphone capsule on the left:. As we see above, the phantom power supply, when switched on, passes through equal-value resistors. These are typically low-noise metal film-type resistors.

The capacitors C1 and C2 block the DC phantom power from getting into the mic input differential amplifier stage. Power for the microphone preamp is pulled off pin 6. The ground and the negative supply for the preamp come from pin 1. The audio output of the preamp appears across the primary of the transformer. Since the power is tapped from the center of the transformer, any audio is cancelled, and the result is pure DC for the preamp. 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.