Phantom Powering a light???

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Vinnydude

Vinnydude

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Ok, so this is a bit of a random one, maybe, i dunno! lol

My idea is, I want to mount a light inside one of the vintage looking microphones, the chrome ones.

The question is, will Phantom power be enough to power a light and if it is, is it possible to do that without affecting the signal from the mic.

Thanks in advance :)
 
well ..... phantom is 48volts so plenty of juice to power a light.
And if you use an LED it won't take much so I imagine it would work. Plus many sources of phantom like mixers can power multiple mics so I don't think it'd be a problem.
Someone who really knows phantom power should be along soon to let us know.
I'm just replying so I'll see when an answer comes.
My opinion is that it should be fine.
 
Phantom power is limited at about 14ma because of the paralell 6.81k resistors so if you want a light and want to power a mic at the same time then you will have to use a low power LED biased to about 5ma as not to suck power away from the mic ......

If you use a power pin and ground and use a 1.5v LED biased to 5ma you will need a 3.2k 1/4w resistor in series with the LED ......


Cheers
 
I'd bet the mic in question is not a condenser, and thus does not need/pull phantom power. Just an educated guess, boarding on a WAG, based on the OP using the words "vintage" and "chrome."
 
StevieB is correct, any of the mics I will be doctoring WON'T require phantom power, so its all about the light!

And from what Minion said, it should, in theory, be fairly simple!
 
Don't forget you need to drain both phantom rails symmetrically or funky stuff might start happening in the rest of the chain.
 
"Drain both phantom rails symmetrically?" Really, what the heck does that MEAN??:confused:
 
Phantom power is 48v through 2 Paralell 6.8k resistors with one resistor going to the Hot and another going to the cold Pins of the XLR ..... the current draw through each resistor affects the voltage on the other resistor ....
to keep current and voltage stable through each resistor and to maximize the current available you can take the positive voltage for your LED from both the Hot and cold on the XLR at the same time......

If you do it that way and use the resistor value I posted above for the LED you will get the full 10ma through the LED and it will be bright ......
 
BUT, the question is, will that interefere with the signal from the mic at all?

If anyone cares to offer some suggestions as to the lights (needs to light up my face when i hold it to my face) and how to wire in the mic capsule that would be awesome :D
 
I am starting to like this idea...

So, if someone wanted an easy-to-use board light, one could use the guidelines in this thread, mount it on the end of a goose-neck, and put a XLR connection on the end, right? Then, just plug it into any open "mic-in" jack?

What might the maximum number of lights one might use? I suppose it would depend on the board, but what might be a practical max to stay below, in general?

I generally have access to three or four boards- a StudioMaster MixDown Classic, a Soundcraft 200R, and a couple of Mackies (both made in USA, as I recall) The Soundcraft has a separate Phantom power switch for each channel, I am not sure about the SutdioMaster, and the Mackies turn PP on or off on all channels with one switch. Would I likely get similar results on all boards?

Do boards that have a XLR/LINE switch, does PP get turned off on that channel's when the switch is in the LINE position? If PP stays on, couldn't one plug in a light into channels one is using for LINE sources?

Thanks for considering these questions- if this leads to a commercially profitable product, I will make a donation to HR!
 
It shouldn"t interfere with the sound , a Lot of condencers have a LED in them .....

and that Light in the above post isn"t a Phantom powered light , it a light that connects to a mixer so you can see the Board in the dark , like when doing sound at a bar .......
 
Are you sure its not phantom powered cause it states 'It is powered by the unit to which it is connected.' on the listing?
 
stevieb said:
"Drain both phantom rails symmetrically?" Really, what the heck does that MEAN??:confused:
Click to expand...

It means you should add voltage from both lines with a couple of resistors instead of hooking it all up with one resistor.

And despite the fact most mixers will happlily supply 10 mA current, some will not. With some older mixers, you'll only get 30V, 4 mA and that's too low for some mics. Especially if you add a LED that tries to draw 10 mA.

There are mics with a LED in them that is continually on when there's phantom power (Samson, with their blue LED's, f.i.) but the better designs (Senn, Rode), just make the LED flicker when you switch on phantom power and when the voltage gets too low. There's a reason for it: lower voltage for the condenser capsule means more noise.

Short: I wouldn't put a LED in a mic. And if you really need to, look for a very high efficiency type that can do with 2 or 3 mA in stead of a 10 mA version.
 
Thanks Cyrano for explaining things so clearly :)

Back to the drawing board :P
 
Vinnydude said:
Thanks Cyrano for explaining things so clearly :)

Back to the drawing board :P
Click to expand...
no need .... you said you're not gonna use a condenser so it doesn't matter how much of the phantom you use. Not gonna affect the mic at all. And there are plenty of LEDs that'll power just fine even if all they can get is 4ma PLUS .... you're gonna be knocking that voltage down to 5v for the LED which means you'll have more amperage available.
If you're not using any phantom powered mics none of this is gonna affect the mics performance in any way.

Plus .... the ONLY boards that are gonna be that restricted as far as power goes will be a pretty small subset of very old ones. You can hook up an LED light just fine.
 
Oh sweet! lol

So, any ideas on a small but fairly bright LED that I should be looking towards?
 
Vinnydude said:
Are you sure its not phantom powered cause it states 'It is powered by the unit to which it is connected.' on the listing?
Click to expand...

Hard to say from the limited post. On the one hand, it says it has an XLR connection, but then it's 12VCD. Wouldn't the 48 volts from phantom power turn it into a flash blub?
 
Vinnydude said:
Are you sure its not phantom powered cause it states 'It is powered by the unit to which it is connected.' on the listing?
Click to expand...

Yes , its powered by the unit , that unit being a mixer , Most good mixers have a spot on them where you can screw in a Goose neck lamp , the lamp actually attaches to the mixer so you can see the mixer in the dark , I got one that looks exactly like it on my mixer ........
 
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