Phantom power voltage? Help!

[LIJ]

I have a small mixing console which delivers 15V of phantom power. I have understood that the standard voltage is 48V. I'm looking for a budget LDC (like Studio Project B1) that will work with 15V. Any tips?

Also is there a diffrense in sound quality if you use 15 an not 48V?

[MartinKantola]

Why not get an external +48V phantom power supply, so that you can pick the mic you like the best? Most microphones perform best with proper voltage (gives better dynamic range). Some don't even work with something as low as 15V.

Martin

[LIJ]

Partly because of money reasons. I have seen one microphone that works with 12V and 48V (and I guess 15V as well) and it sounds very good as well. Would there be a sound diffrence when using a lower voltage if the microphone is designed fo it?

[MartinKantola]

Let's put it this way, it's probably easier to make a good mic if you have +48V available. Regarding the cost issue for an external phantom power supply, a Behringer PS400 is only 25 euro.

But trust your ears if you've found a mike you like!

Martin

[punkin]

Are you measuring the voltage when the mic is plugged in with meter across the connection or just raw at the output. Some power supplies won't produce rated power unless there's a load.

[crazydoc]

Originally Posted by punkin

Are you measuring the voltage when the mic is plugged in with meter across the connection or just raw at the output. Some power supplies won't produce rated power unless there's a load.

And some will only produce the rated voltage without a load.

You'd best get a 48v phantom supply. If you're handy, here's a cheap battery powered DIY box from Harvey:

Originally Posted by Harvey Gerst

I think I can explain it pretty simply. You'll need:

a small box,
a female and male XLR,
5 - nine volt batteries,
5 - nine volt battery clips,
two - 6,800 ohm (1%) resistors,
and two small, non-polarized 10 mfd capacitors.

Wire all 5 of the nine volt batteries in series, the (-) of one battery connected to the (+) of the next battery.

Connect the (-) pole of the last battery to Pin 1 of both XLR plugs.

Connect the (+) pole of the first battery to one end of both 6,800 ohm resistors. Tie the other end of the resistors to Pins 2 and 3 of the female XLR (the XLR that goes to the mic).

Connect one of the 10 mfd capacitors from Pin 2 of the female XLR plug (the XLR that goes to the mic) to Pin 2 of the male XLR plug (the XLR that goes to the board).


Finally, connect the other 10 mfd capacitor from Pin 3 of the female XLR plug (the XLR that goes to the mic) to Pin 3 of the male XLR plug (the XLR that goes to the board).The two capacitors prevent the phantom voltage from getting back into the board.

Mount the whole thing in the box, and you're ready to go. You can add a two pole (off/on switch in series with the batteries, if you wanna get fancy and have a shutoff. You can even put an LED in it to indicate "On").

Current drain is minimal, so the damn thing should last forever (even if you leave it on constantly).

If you pick up any stray hum from the box, line it with aluminum foil and connect the foil to Pin 1 of either XLR.