Phantom power

[chriskreidler]

Can phantom power hurt anything? I need it for some floor mics, but I also need to plug in a laptop to the mixer at the same time. Could phantom power hurt the laptop?

[Footer]

No, you should be using Mic Level inputs for your floor mics and Line Level inputs (usually 1/4") for your laptop. Phantom power is not sent over line level connections. I run laptops and all that fun stuff off of consoles with global phantom power all the time without a hitch.

[museav]

If you want to run the laptop into a mic input (or two inputs) get something like this, Whirlwind / Direct Boxes or this, Pro Co Sound |.

[rwhealey]

Originally Posted by Footer

No, you should be using Mic Level inputs for your floor mics and Line Level inputs (usually 1/4") for your laptop. Phantom power is not sent over line level connections. I run laptops and all that fun stuff off of consoles with global phantom power all the time without a hitch.

Some mixers do not have 1/4" line inputs, but only have an XLR with a pad, like our Soundcraft MH3.

If you don't have line inputs, I would recommend the DI solution.

[avkid]

Originally Posted by rwhealey

Some mixers do not have 1/4" line inputs, but only have an XLR with a pad, like our Soundcraft MH3.

You might want to look again.

[rwhealey]

Originally Posted by avkid

You might want to look again.

The top connector is a 1/4" Direct Output

The middle two are balanced insert send and balanced insert return. The return (if I am reading the schematic correctly) could be considered a "line in" but is after the high pass filter.

The bottom is the XLR, while the "gain range switch" is the pad for line level sources.

[FMEng]

As others have said, phantom power applied to anything other than a microphone or direct box can cause problems.

This is slightly off topic, but it is wise to avoid connecting vintage ribbon mics (think RCA 77) to anything with phantom applied. Those mics have a grounded center tap. When one connector pin makes before another, the current flowing can induce movement in the element and destroy the ribbon. If I have to use phantom around a ribbon mic, I make sure the connections are made before turning on the phantom supply.

This is NOT a problem with any other type of mic, dynamic or otherwise.

[themuzicman]

That iFace looks really great, the idea of having consumer to pro cables! Wish it wasn't so expensive, really love the idea.
I'll stick with my $25 Behringer DI box and a patch cable for now. Anyone have any experience with the iFace, any reviews to be had?

[spiwak2005]

Originally Posted by FMEng

This is NOT a problem with any other type of mic, dynamic or otherwise.

Also slightly off topic - I was always taught never to plug in or unplug anything with phantom power on. Is this not true? Is it ok to plug/unplug dynamics and/or condensors with phantom on?

[Dionysus]

Originally Posted by spiwak2005

Also slightly off topic - I was always taught never to plug in or unplug anything with phantom power on. Is this not true? Is it ok to plug/unplug dynamics and/or condensors with phantom on?

One of my sound teachers told me much the same thing, adding to wait for 5 minutes until phantom was totally gone. He said that patching/unpatching with phantom active on the channel could eventually damage the preamp/phantom circuits in the console.
He said that it didn't necessarily happen but better to be safe than sorry.
Didn't matter much, the consoles we used all had individual phantom for each channel or at least a set of channels. We only turned phantom on where it was needed.

Not sure how much truth there is to it. I do know about electronic circuits from my schooling as an electrical apprentice, so I can say it is somewhat plausible.

*shrugs* on smaller consoles I never bother to turn phantom off. If I turn it off, the next person comes crying to me that they can't get some of the microphones to work. lol.