[LAU] Some phantoms are stronger than other phantoms.

Philipp hollunder at lavabit.com
Mon Mar 29 05:55:12 EDT 2010

Excerpts from James Stone's message of 2010-03-29 09:47:21 +0200:
> Interesting... But apparently this is not uncommon - see:
> http://www.tomshardware.co.uk/forum/41809-32-thought-behringer-clue
> Seems. It has been designed primarily with behringer's measurement mic
> in mind. Not reallly an appropriate mic amp/eq for a high end mic.
> On 29/03/2010, Brent Busby <brent at keycorner.org> wrote:
> > I was noticing the Behringer DEQ2496 spectrum analyzer / EQ has a XLR
> > input for a mic with flat EQ to be connected for room analysis, and the
> > mic input does have phantom power supplied.
> >
> > However, it says +15-volt phantom power.  Fifteen volts?  Isn't phantom
> > power normally 48 volts?  I was hoping to use an Earthworks TC30K mic
> > with it, since I have two of them, and they are basically flat out to
> > beyond the human audio range, but they say they require 48-volts at
> > 10mA.  Where do you get 15-volt phantom power?
> >
> > --
> > + Brent A. Busby     + "We've all heard that a million monkeys
> > + UNIX Systems Admin     +  banging on a million typewriters will
> > + University of Chicago     +  eventually reproduce the entire works of
> > + Physical Sciences Div. +  Shakespeare.  Now, thanks to the Internet,
> > + James Franck Institute +  we know this is not true." -Robert Wilensky
> > _______________________________________________
> > Linux-audio-user mailing list
> > Linux-audio-user at lists.linuxaudio.org
> > http://lists.linuxaudio.org/listinfo/linux-audio-user
> >

Also, the real provided voltage might be different from device to
device. I did measure an Allan and Heath desk and some digi-something
and they behaved quite differently. The digi provided the voltage
immediately after turning it on and quite exactly what you'd expect
while the a&h took a few minutes to reach the 48V and it climbed up
further. Notice that this was measured without any load, simply with a
voltmeter, so the reality might look different. However, I also doubt
that 2V off mean a lot to mics.

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