I own a oud player a couple of ear drums

[eman kayker]

Hi everybody
I was recording a oud and wanted to use my earthworks with the A12. When I turned the phantom on it started screaming a tone going from 1k and up, like a siren. I've used those preamps with shoeps already, and they had no problem. I've used them with dynamics or a mic with external +48v and no problem either.
What could be wrong?

[tpryan]

Did you verify that you actually get +48v on pins 2 and 3?.

Does the sound eventually stop?

What does Earthworks have to say?

The phantom power ramps up slowly and takes at least 5 seconds to reach full voltage. I suspect that the Earthworks output amplifier is unstable at low voltages and is oscillating. Keep phantom power applied for at least 10 seconds and see if the noise stops. Unless you've got a wiring problem it's extremely unlikely to damage the mic.

[eman kayker]

So I finaly got a chance to check it, and it doesn't look too good.
I've recorded as I turned the phantom on and posted an mp3 here, but
WARNING:
it is loud...
http://www.brhmpf.net/guest
the file name is
DANGER OdB FS-GAIN.mp3
I decided not to leave it at 0 dB FS and did a gain of 10 or more db's, but it's still LOUD,
So, yes it stops after a while but it sounds like a dried capsule of a computer mic.
I checked the mic directly in my mixer and they still sound ok, they didn't do ¨the screaming pig will tear your eardrums¨ sound again

[tpryan]

With the Earthwork mic connected, measure the DC voltage at pins 2 and 3 of the input connector after phantom power has been on for at least a minute. What do you get?