At 6:07 AM -0700 3/21/07, umashankar wrote:
>
>i think the culprit in all these is the switched mode phantom power
>and probably the best thing would be an outboarded phantom power. it
>does not always have to be 48 volts - depends on the mike of course,
>but i have run oktava mko12 (a simple resistor for the condensor DC
>voltge) on 18 volts with only a small loss in sensitivity.
>
>umashankar
This possibility goes way back in our discussions. I bought the parts
to make up one that supplied 48 volts via multiple batteries with
Klas' help on the schematic. A few weeks later, Eric Benjamin tested
my Rolls PB224 portable phantom power supply and reported that the
noise level was probably insignificant even with the best gear. This
was also consistent with my test comparing the NT1-A->744 (phantom)
vs NT1-A-> Rolls PB224 ->744 (non phantom). As the Rolls is only
$70USD, the need for a battery-only unit became lower, but no A/B
test has been done to the best of my knowledge.
If any one has a battery-only-powered phantom supply they could send
me for a few days, I'll run an A/B test. The NT1-A's will run fine on
30 volts. Rob D.
--
Rob Danielson
Peck School of the Arts
University of Wisconsin-Milwaukee
http://www.uwm.edu/~type/audio-art-tech-gallery/
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