[LAU] Terrible mic ground noise

[jonetsu at teksavvy.com]

Le 01-04-2013 00:59, Len Ovens a écrit :

> Is this the way the whole house is wired? (or garage or whatever) 
> This may
> very well be some of your problem.

Fortunately, no.  It is only an extra wall the previous owner has made 
in the basement.

> It would seem that your whole setup is
> floating. I would feel comfortable fixing the wiring to make sure I 
> had
> proper grounding even if it just meant running one wire for that 
> purpose.

The setup is now connected via a 3-prong extension to an outlet that is 
grounded.  No More Ground Noise.  This is so nice.

> You are getting sound from your mic... therefore it must be a dynamic 
> mic.
> It is quite possible that whatever I looked up on m-audio's website 
> is not
> what you have. So it is not worth worrying about getting phantom 
> power to
> it if it is working without it.

I've gotten the specs from:

http://www.m-audio.com/images/global/manuals/060817_PULSAR_UG_EN01.pdf

This is the mic I have.  It says Pulsar on it.  Not Pulsar 2.  Bought 
it in 2006 or so.  Looks same as in the specs.  Same accessories, same 
everything.

The specs specifies a 48V phantom power.  But from your comment and 
Fons', it seems that the phantom is actually the music recorded by it !  
And this is not from a guitar amplifier.  I record acoustic guitar and 
bass.  Can have a magnet effect of some sort in there.

> That would be the way, but if you are getting sound at all, your mic
> either has power already or doesn't need it. If it was indeed a 
> phantom
> powered mic you would get no audio from it at all, so I think you 
> have a
> dynamic mic of sorts.

So now this mystery remains.  I was by the music shop today but they 
were closed.  With the phantom and all, I'm not sure I'd get a phantom 
power supply on April Fools anyways.

But the Pulsar mic works.  Just recorded again some other things 
earlier today.

Is it possible to probe the microphone's pins and by the impedance or 
something find out if it is made for having a phantom power supply ?  I 
have a meter that I can put to good use.