is was wondering if it was possible to buils a phantom power unit for an mic because i don`t have enough money to buy one
Harvey Gerst said: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.