When do i turn on phantom power

I'm with Jon; given proper professional design, hot plugging is possible but not advised. I've done it a couple of time when I needed to swap or move a pro mic right then and didn't have the time to run back to the recorder, but otherwise I kill p48 first. I can't find the post at the moment, but I think dsatz explained part of this once. It's like, how far is it today?

I think it's four hours, and someone else comes in at 11 hours, and well, then we'll My Aerco is always on when using external power. Should I have my mics plugged in prior to connecting the battery or is it going to matter in this case?

Church-Audio 44 Needs to get out more Posts: Gender:. Never hot patch phantom power mic inputs if you can avoid it. This can over time damage the front end of a preamp. It can damage transistorized preamps and cause a gradual breakdown of the transistors and some types of opamp input stages especially ones using a fet topology..

You do not need to worry about turning off the phantom power before plugging in a mic. But, you could damage your loudspeakers if your mixer is turned up when you plug in a microphone. This often results in a loud "pop". Turn the mixer's Master control down before connecting or disconnecting any microphone.

This will prevent damage to your loudspeakers. Additionally, because of the way the power flows through the pins of an XLR cord, a normally working mic and cable will not result in a dynamic mic being damaged by having phantom power turned on.

However, if there happens to be an imbalance in the amount phantom power voltage being applied to each pin, the power can damage or destroy a dynamic mic.

This is particularly true with ribbon mics a type of dynamic mic , where an imbalance of power flow can destroy the ribbon in the mic. Yes, and you should also turn off power before disconnecting a mic. The loud pop that is produced when you do either of these actions can result in damage to your equipment not just the microphones, but possibly your speakers, as well. No voltage is present between pin-2 and pin Phantom power is used to power the active components of active microphones.

Generally speaking, it is used to power the impedance converters and internal preamps of active microphones along with other active circuits. It is also used to polarize the capsules of condenser microphones that require external polarization. Note that not all active microphones run on phantom power. DC bias and external power supplies are also common, depending on the type of mic. More on this in the other microphone powering methods section.

Phantom power is ultimately produced using electricity from the power mains or batteries that power the phantom power source.

Phantom power sources include:. The above-listed sources contain active units that convert mains power or battery power into phantom power for microphones.

This 48 V DC is designed to pass through balanced audio cables on the audio lines. Note that microphones typically receive phantom power through their connected XLR cable. 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.