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Gear / Technical Help => Ask The Tapers => Topic started by: macula on April 19, 2008, 04:13:27 PM

Title: NEWBIE QUESTION: Phantom power and mic connections
Post by: macula on April 19, 2008, 04:13:27 PM

Recording 101 question:

I have a condenser microphone and a portable digital recorder. Which of the following sequences is correct?
 
SEQUENCE A
1. Connect microphone
2. Turn phantom power ON
3. Turn phantom power OFF
4. Disconnect microphone

SEQUENCE B
1. Turn phantom power ON
2. Connect microphone
3. Disconnect microphone
4. Turn phantom power OFF

I cannot find a consistent answer. THANK YOU!

Title: Re: NEWBIE QUESTION: Phantom power and mic connections
Post by: Javier Cinakowski on April 19, 2008, 04:41:00 PM

sequence A my friend.  I am suprirised anyone actually suggested B, that could cause damage....

Title: Re: NEWBIE QUESTION: Phantom power and mic connections
Post by: macula on April 19, 2008, 04:49:37 PM

Thank you!

I made a mistake (once!) and unplugged a condenser connected directly to a portable recorder. Everything seems fine (phew!) after testing for damage, but how can I be sure that indeed no harm was inflicted on the mics or the Korg? Is this something I would have noticed immediately? Or can the damage be subtle and hard to hear at first?

Thanks again.

Title: Re: NEWBIE QUESTION: Phantom power and mic connections
Post by: wheresjerry on April 20, 2008, 08:21:53 AM

I own a pair of SP C-4's which require phantom power, and instead of fooling around with the phantom power switch on my pmd 671, I make all of my connections with the unit in the powered off position on the recorder.  I follow the general principle of connecting and disconnecting all components with the power unplugged when it comes to stereo components, so I can probably safely assume that this would hold true to unplugging mics from a recorder.  Just get in the habbit of shutting off unit before making any connections.... ;D

Title: Re: NEWBIE QUESTION: Phantom power and mic connections
Post by: DSatz on April 20, 2008, 04:23:58 PM

With well-designed professional equipment neither sequence of operations is likely to damage anything. But step 3 of sequence B could send very high levels of noise through your preamp and whatever other equipment is connected to it (e.g. your eardrums if you're wearing headphones), so sequence A is preferable on those grounds.

A 48-Volt phantom power supply should never exceed 52 Volts when left "open" (nothing connected to it), but many phantom power supply circuits in low-cost portable equipment don't follow the official standards very well, and the first version of the DIN standard allowed 54 Volts. Some condenser microphones can be damaged very quickly (and perhaps expensively) if the phantom power supply presents too high a voltage when the microphone is connected. Again, that's another reason to prefer sequence A if you haven't had a chance to do careful bench tests with the given piece of equipment.

--best regards