So dumb question. Dynamic Mics and Phantom Powering.

G

GrooveBassman

New member
OK I'm looking into doing my bands demo. I've got some decent mics. (decent in the minds of mere mortals that is). Everything I've got now is dynamic. I really want to take the next step and get some condensors. But here is the problem. My board a cheapy yamaha mx 12/4 only allows me to switch the phantom on all channels. The information I've got has been conflicting. I've been told phantom won't hurt the dynamic mics. And I've been told don't do it cause it'll fry them. So wich is right? And ok someone tell what is the ultimate entry level condensor for drums over head. budget being in the 300 range. Sorry i know this is a dumb question but I'm just a newbie.
 
Well,

I've never fried an SM57 while using phantom power on before. We had a board that had a phantom power switch on the back, and never knew it. It was on for like 2 years, and it had about 5 57's and a 58 plugged into it. I'm not saying do it, by any means, someone else will give you that answer, probably Harvey, but I'm just saying it didnt affect our mics in any noticable way.
For cheapies, check out the Oktava, and the Marshall small condensor.
Peace,
Paul
 
Thanx

Yeah Right now I've got a bunch of 57's a couple of 58's and a D112. I'm debating on getting the condensors next or going for the senheiser tom mics next. But since i'm moving and my disposable income is is tied up I've got plenty of time to think on it.
 
Most mics use a transformer as the output to the board preamp. A transformer won't pass DC. That's how phantom power works; they put +48 volts DC on pin 2 and 3 (relative to ground), and then the transformer stops it from going any further. But now they have that voltage at the mic and they can tap off of it to power the capsule and the electronics. Can it hurt a dynamic mic? Yes under a couple of conditions.

It could damage a mic if one side of the transformer or the cable is shorted to ground, or the connector doesn't make contact with both signal pins at the same time. For the most part, it shouldn't be a problem, but it's always a good idea (whenever possible) to turn off phantom power before connecting or disconnecting ANY mic.

Ribbon mics are most suceptable to phantom power since the ribbon acts like a fuse, and it will simply break or vaporize, but the transformer will usually offer some safety, even there.
 
Groove - I had the exact same question and situation as you a few months ago. I had been using Shure Sm57 & 58's for years and finally bought my first condensor (a Rode NT-1) because I wanted one good mic for vocal overdubs. My mixer is an Alesis Studio 32 which also puts out phantom power to all channels or none. I asked around and I got exactly the same answer as Mr. Gerst - basicly there is no problem unless you have a bad or improperly wired cable. Just for paranoia sake I unplug any mics I wont be using, but having been doing it for a few months now with no problems I would say don't worry about it.
 
I purchased an audio technica 3525 mic on ebay for $147.00 Canadian, because I wanted to try a condensor mic. I'm presently using a Shure 58sm and like it but wanted a more 'up front' sound. Anyway, I have an Audio Buddy and wonder if that's sufficient for phantom power. I read somewhere that the Audio Tech 3525 has it's own power? The more I learn the more I realize I don't know. Thanks everyone for getting me this far.
 
Joan, does your mic have a battery? if not, it doesn't have it's own power.


as for the original question......... I have never had any problems using phantom power with mics that didn't require it...........................also, the audio technica 3035's are very nice and are only about 199.99 at most music stores............i don't know what they list for, but the store will most definitely go down to 199.99 and maybe further if u have bought a lot from them in the past.
 
So here you go. Phantom power is based on the principle of common mode rejection, which is to say the power travels to the mic on the same two wires which carry the sound from the mic. When the phantom power gets to the mic, the transformer in the mic cancels out the power, unless there is some method of using it in place. This is a long way of saying, phantom power does not get anywhere near the parts of the mic that might be damaged. Even if, some how, the power did get past the transformer, the components in a dynamic mic are quite robust, and would not be hurt. Some ribbon mics may be damaged by phantom, but all other dynamic mics are not affected by phantom power. This was one of the design criteria when Neumann invented phantom power way back when (I think it was in the 1940's), and this was one of the reasons it became a standard for how to power condenser mics.

Other wise, why would even cheap mixers have universal phantom switches? Right?


Light

"Cowards can never be moral."
M.K. Gandhi
 
I suppose this is more of a 'live' thing but my p.a. mixer has a common 48v and I've had no problems using both dynamics and condensers except for one thing; don't plug or unplug the LXR connectors with the 48v switch on......very nasty to your speakers.
 
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