Can improper phantom power procedure damage condensers?

[mellotron]

I haven't been keeping track these past few months I've begun recording, but are you not supposed to take out the mic while the phantom power's still on? The proper procedure is to power it on after plugging in and powering off before, right? Have I been doing any serious damage if I've done it the wrong way a few times?

[light40]

It's not recommended, but as long as your mic's still work you should be fine.

I think it is the pop that goes back into your pre-amp or interface. I would be more worried about damaging that.

But like I said, if everything still works, your fine!

[mellotron]

Thanks. I'm wasn't sure if it could result in sound quality loss in the microphone. I'm more worried about my AT4047 than my Firebox. I don't notice anything, so I'm assuming that like you said, as long as everything still works, it's okay.

[Wireneck]

I don't know one way or the other but why take the chance? It isn't like turning off phantom power is an involved process.

[Farview]

I have had the phantom power on all channels of my board on for 20 years. I always plug and unplug the mics with the phantom on. I have never lost a mic due to that.

[crazydoc]

Apparently many studios always leave phantom on, whether by choice or more likely by convenience. In the following thread there is argument on both sides by experts in the field, without definite conclusion that I can see, except that connecting or disconnecting mics with phantom off is possibly safer for theoretical reasons. So I think, for practical purposes, it makes no difference.

http://recforums.prosoundweb.com/ind...1521/0/0/3472/

[Farview]

I was worried about it at first as well. But when I found out that most big studios had the phantom turned on all the time, I figured that it couldn't be that big of a deal. They were plugging and unplugging vintage Neumanns all day without a care...

[dgatwood]

Originally Posted by crazydoc

Apparently many studios always leave phantom on, whether by choice or more likely by convenience. In the following thread there is argument on both sides by experts in the field, without definite conclusion that I can see, except that connecting or disconnecting mics with phantom off is possibly safer for theoretical reasons. So I think, for practical purposes, it makes no difference.

I'm trying to think of a situation where disconnecting one could matter, but I really can't. Plugging one in while it is hot, however, is not such a bright idea. You're creating a much bigger surge of power than you get when you turn on/off the phantom power switch on a preamp and/or turn the preamp on/off. In the long term, that's not good for various components in the mic, and particularly power filtering caps.

[Farview]

I have never actually heard a real story of anyone blowing a mic by plugging it in with the phantom on. It kind of reminds me of the 'ribbon mics being toasted be phantom power' thing. It's just something that gets repeated endlessly, even though it is only true in some very isolated, extremely rare instance.

[JM350]

Originally Posted by Farview

It kind of reminds me of the 'ribbon mics being toasted be phantom power' thing. It's just something that gets repeated endlessly, even though it is only true in some very isolated, extremely rare instance.

I don't know that it is true but I wouldn't be surprised if Neumann and/or AKG spread this rumor to further the idea that ribbons were fragile and sell more of their condenser mics.

[dgatwood]

Originally Posted by Farview

I have never actually heard a real story of anyone blowing a mic by plugging it in with the phantom on.

As I said, you're not likely to blow a mic. You're likely to cause progressive degradation that will eventually cause the mic to misbehave, but those problems won't be associated with plugging it in because it won't be a sudden change in the sound of the mic. Instead, they'll be blamed on age and cheap electrolytics.

[Farview]

Originally Posted by JM350

I don't know that it is true but I wouldn't be surprised if Neumann and/or AKG spread this rumor to further the idea that ribbons were fragile and sell more of their condenser mics.

Well, there was a time when it was very true that phantom power would fry a ribbon mic. But 50 years later, the ribbom mics that are designed like that are very rare, very expensive and only really in the hands of people who know how to take care of them.

I doubt it's a conspiracy, it's juts old information.

[JM350]

Originally Posted by Farview

Well, there was a time when it was very true that phantom power would fry a ribbon mic.

As I understand it only the lower budget unbalanced ones would have an issue with phantom not the ones you would have found in studios which would have had balanced ones like the RCA 44 or 77 or a Coles 4038.

Originally Posted by Farview

I doubt it's a conspiracy, it's juts old information.

I don't know but if we are going to have a silly old inaccurate story like this we might as well have a conspiracy theory to go with it.

[MCI2424]

Originally Posted by mellotron

I haven't been keeping track these past few months I've begun recording, but are you not supposed to take out the mic while the phantom power's still on? The proper procedure is to power it on after plugging in and powering off before, right? Have I been doing any serious damage if I've done it the wrong way a few times?

Electrically speaking, taking out a powered mic can damage the mic IF when you pull it out, one side is still powered up. Same with plugging in. The diaphram normally does not see any voltage potential between the 2 pins UNLESS one pin is grounded and the other pin is +48vDC. Then there is +48vDC accross the diaphram.
Normally, if you pull the mic out with PP on, one side would be floating and the other side could have +48vDC connected. Technically, that would not harm the mic. The one scenario that will harm the mic is if the cable had pin 2 or 3 shorted to ground. The way I see it, if this were the case, you would harm the mic when you turn PP on anyway, so make sure your cable is good BEFORE you use it.

On to dynamic mics, there is the possibility of magnatising the transformer if pin 2 or 3 were shorted to ground, again, make sure the cable is good.

So, my take on this is: Turn off PP before extracting and inserting. Why take the chance of harming the mic if all it takes is a simple power up/power down routine? And more important, test your cables and keep them in good condition. If you like to take chances, by all means there are plenty of recording engineers that have, and do plug in mics with PP on. Most electrical engineers would not.

I forgot to mention that virtually all modern Phantom Power circuits have self-limiting resistors that will not allow a shorted pin 2 or 3 to kill the mic, but there are plenty of older consoles and mic pre-amps that are not limited. You are much safer with the limiting resistors. This still will not save a ribbon mic much.

[MCI2424]

Originally Posted by Farview

I have never actually heard a real story of anyone blowing a mic by plugging it in with the phantom on. It kind of reminds me of the 'ribbon mics being toasted be phantom power' thing. It's just something that gets repeated endlessly, even though it is only true in some very isolated, extremely rare instance.

Mr. Josephson has some good stories that happened to him personally. I remember reading about it.

[Farview]

Originally Posted by JM350

As I understand it only the lower budget unbalanced ones would have an issue with phantom not the ones you would have found in studios which would have had balanced ones like the RCA 44 or 77 or a Coles 4038.

No, it's the really ancient ones from the 50's and before. I can't remember what the difference is (alzhiemer's) but it is a design thing. These mics were also designed before phantom power existed...