Power for Phantom at DVinfo.net

Roy Feldman · February 5th, 2014, 10:14 AM

On my camera I have 2 xlr ports with the ability to power 48 phantom. When I am only using one input I can switch to make the signal go to both channels, unfortunately I cannot control the volumes independently, so I bought a splitter (to set one channel lower than the other) for the XLR MIC> Camera cord.. My question (before I fry my camera) is Do I turn on Phantom power to both inputs or just one?

Seth Bloombaum · February 5th, 2014, 11:28 AM

Quote:

Originally Posted by Roy Feldman

On my camera I have 2 xlr ports with the ability to power 48 phantom. When I am only using one input I can switch to make the signal go to both channels, unfortunately I cannot control the volumes independently, so I bought a splitter (to set one channel lower than the other) for the XLR MIC> Camera cord.. My question (before I fry my camera) is Do I turn on Phantom power to both inputs or just one?

Just one! A single mic is only going to need a single 48v phantom source. (edit: removed incorrect info, see posts 4 and 6 below)

Warren Kawamoto · February 5th, 2014, 12:21 PM

Quote:

Originally Posted by Roy Feldman

On my camera I have 2 xlr ports with the ability to power 48 phantom. When I am only using one input I can switch to make the signal go to both channels, unfortunately I cannot control the volumes independently

What camera is this? I find it very strange that you can't control the inputs independently if it has 2 inputs.

Richard Crowley · February 5th, 2014, 12:40 PM

Providing phantom power from BOTH mic inputs ON THE SAME DEVICE will not "fry" the microphone. Phantom voltage does not "add".
HOWEVER this DOES NOT APPLY if you are feeding a microphone to DIFFERENT destinations. It is never wise to hard-join mic inputs from DIFFERENT gear without using a proper transformer-isolated splitter.

Jay Massengill · February 5th, 2014, 02:15 PM

You should also test your splitter cable to make certain that it is correctly wired.

Of course with phantom power it's important to test any XLR cable to make sure it is properly wired and hasn't developed broken, shorted, or intermittent connections.

A cable tester that can latch onto intermittent faults is very helpful for this.

Seth Bloombaum · February 5th, 2014, 05:02 PM

Quote:

Originally Posted by Richard Crowley

Providing phantom power from BOTH mic inputs ON THE SAME DEVICE will not "fry" the microphone. Phantom voltage does not "add"...

I had to scratch my head for a moment... then realized that (properly wired) splitting would provide parallel power sources, doubling the available amps, *not* series, doubling the supplied voltage.

Quite right, thanks for the correction Richard.

You only need one channel supplying phantom, but two would be unlikely to hurt anything.

February 5th, 2014, 10:14 AM	#1
Roy Feldman Regular Crew Join Date: Jul 2007 Location: Grosse pointe, michigan Posts: 189	Power for Phantom On my camera I have 2 xlr ports with the ability to power 48 phantom. When I am only using one input I can switch to make the signal go to both channels, unfortunately I cannot control the volumes independently, so I bought a splitter (to set one channel lower than the other) for the XLR MIC> Camera cord.. My question (before I fry my camera) is Do I turn on Phantom power to both inputs or just one?

February 5th, 2014, 12:40 PM	#4
Richard Crowley Trustee Join Date: Aug 2007 Location: Portland, Oregon Posts: 1,238	Re: Power for Phantom Providing phantom power from BOTH mic inputs ON THE SAME DEVICE will not "fry" the microphone. Phantom voltage does not "add". HOWEVER this DOES NOT APPLY if you are feeding a microphone to DIFFERENT destinations. It is never wise to hard-join mic inputs from DIFFERENT gear without using a proper transformer-isolated splitter.

February 5th, 2014, 02:15 PM	#5
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Re: Power for Phantom You should also test your splitter cable to make certain that it is correctly wired. Of course with phantom power it's important to test any XLR cable to make sure it is properly wired and hasn't developed broken, shorted, or intermittent connections. A cable tester that can latch onto intermittent faults is very helpful for this.