Phantom Power - Alesis Studio 12R Reference Manual

Phantom power

Certain types of microphones (called condenser microphones) require a DC power supply
from the mixer. "Phantom power" sends 48 volts of DC through the microphone cable. If
any of your microphones need phantom power, turn on the [PHANTOM POWER] switch
on the Studio 12R's back panel to connect all the XLR MIC IN jacks to the Studio 12R's
internal 48 volt phantom power source. Since the power is applied equally to pins 2 and 3,
phantom power should not affect dynamic microphones (which do not require phantom
power). However, make sure that your microphone cables have no short circuits or
intermittent connections to avoid damage to the system.
Avoid connecting or disconnecting any microphones while [PHANTOM
POWER] is turned on. Make all connections with the Studio 12R powered off. If this
is not possible, make sure the channel's fader and [TRIM] are down, make the
connections, then turn on the [PHANTOM POWER] switch on the back panel before
bringing the fader and [TRIM] back up. Many microphones make a loud "pop" when first
powered, so make sure your faders are down to avoid damaging your speakers or hearing.
Never connect the MIC jack to an UNBALANCED source or to a
line-level device (such as a tape recorder or synthesizer) when
phantom power is being used.
If none of your microphones need phantom power, leave the phantom power switch off.
Studio 12R Reference manual
Connections
11