PHANTOM POWER DO & DONOT CHART
DODONOT
If you are plugging in a condenser microphone,Worry about your other microphones as long
do verify that your microphone can beas their output is balanced and floating.
phantom powered.
Ensure that the microphoneOs output is lowConnect microphones or devices that do not
impedance, balanced and floating. This isconform to the DIN 45 596 standard.
especially important for vintage ribbon
microphones like the RCA 44BX and 77DX.
Mute the sound system when turning theDonOt connect A-B or T-system microphones
phantom power on or off, or when connect-(another remote powering system) without
ing or disconnecting microphones. If yousuitable adaptors.
forget, the resulting loud, nasty POP may be
your last.
the DC power is applied common-mode. TheWhat works?
audio travels via pins 2 and 3, the power trav-
To be compatible in a phantom powered
els between pins 2 and 3 simultaneously, and
system, a device (microphone, preamp with a
pin 1 is the ground for both audio and power.
microphone-style output, or direct box) must
Microphones that do not require power simply
have a balanced and floating, low-impedance
ignore the DC present between pin 2/pin 3 and
output. This includes all microphones commonly
pin 1. If you measure with a voltmeter between
used for sound reinforcement and recording,
pin 2 and pin 3, you will read 0 Volts DC. This¨
such as the Shure SM58, SM57, Electro-
is what your dynamic microphone sees. Measur-¨
Voice RE-15, RE-16, RE-20, ND series,
ing between pin 2 and pin 1, or between pin 3¨¨
Beyer M160, M500, AKG D224, D12, D112,
and pin 1, you will read the phantom power
and many others.
voltage, usually 48V, without a microphone
If you are fortunate enough to own any tube
connected. The dynamic microphone, as well as
condenser microphones, such as the AKG¨ C12,
your balanced mixer input, ignores this voltage.
Neumann¨ U47 or U67, these microphones
Lately, the term phantom power has been
may be connected in a phantom powered system
perverted to refer to any remote powering
and will operate without regard to the presence
system. In the strict sense of the DIN standard,
or absence of phantom power. They will always
this is not true. Furthermore, microphones or
require their external power supply (which
transducers that claim to use this system are
must be plugged in and turned on).
not compatible with the DIN standard and will
What doesnOt work?
almost certainly be damaged if connected into
such a system. Fortunately, these systems useThe list is short:
tip-ring-sleeve phone plugs or miniature XLR
1. Microphones with unbalanced outputs.
connectors and they are usually associated with
2. Microphones with grounded center-tapped
instrument pickup applications2.
outputs. Many old ribbon microphones were
Phantom powering is defined in DIN standard
supplied connected this way. Have a techni-
45 596 or IEC standard 268�15A. Your Mackie
cian lift the ground from the center tap.
Designs mixer conforms to this standard.
3. High-impedance microphones.
4. Microphones that exhibit leakage
between pin 2 or pin 3 and pin 1. These
microphones will sputter and crackle
2when phantom power is applied and willThere is another remote powering system called A-B or
T-system powering. It uses pins 2 and 3 to carry both power andwork fine when you turn off the phantom
audio. It is not compatible with dynamic microphones or phantom-
power. Get the microphone repaired.
powered microphones.
47 |
ACEC
