phantom power

Hey I am using a latop to record vocals. I have a shure sm 86 condensor mic connected to a preamp. Audacity is not picking up much sound from the mic at all. There is also no difference in sound or volume when the phantom power is off or on. I have the input knob turned all the way up and have audacity picking up as much sound as possible from the mic but still very little sound is being picked up. How can I get more sound to be picked up from the mic?

<<<shure sm 86 condensor >>>

That appears to be a very nice microphone, although it has almost the same curves as an SM-58 and I’ll bet the SM-58 is a lot harder to break.

Anyway, your microphone takes phantom power from the MicPre–either 12v or 48v. There should be no output at all if the phantom power is missing, so you have something seriously magic going on. Who made the preamp and how do you know it works? Is there a level indicator on the MicPre??

Koz

The specification for the SM86 states that phantom power should be in the range 11 to 52 Volt DC.
The load impedance should be at least 600 Ohm.

Most stand-alone microphone pre-amps that have phantom power, and mixing desks (if they have phantom power) should meet these requirements, but check the specifications.

The phantom power supplied by computer sound card microphone sockets is 5 volt, and is not sufficient to power the SM86.

<<<The phantom power supplied by computer sound card microphone sockets is 5 volt, and is not sufficient to power the SM86.>>>

Plus the sound card isn’t electrically balanced and the battery isn’t “phantom” because it goes up to the microphone on its own wire–or at least that’s how it was designed.

So the upshot is that if you have sound coming out of your microphone with the phantom power switched off, then something is broken.

Koz