10 May
2009
10 May
'09
6:37 p.m.
Brent Busby <brent(a)keycorner.org> writes:
Just so the original poster knows, switching on
phantom power sends 48
volts of DC power straight into the attached device, whether it was
designed to take it or not.
This is accurate, but misses an important detail. The 48V DC is applied
between the cable shield and the balanced pair, not between hot and cold
of the balanced pair. If your dynamic/ribbon microphone is correctly
wired (i.e. with the element between hot and cold, not between hot and
the shield) then it's safe, because there is no DC across the element;
if it's not correctly wired, you should fix it anyway -- both because
you'll get better noise performance, and in case someone *else* plugs it
into an input with phantom power...
--
Adam Sampson <ats(a)offog.org> <http://offog.org/>