Crest Audio X-SERIES X 20R - Manual (Page 21)

Mono Input Channel
1
Rear Panel Features
48 V Phantom Power
+48 volts DC is applied equally (thru current-limiting resistors) to both pins 2 and 3 on
the mic-input XLR connector. This feature is used with condenser microphones and
active direct boxes that require an external DC voltage (phantom power) in order to
operate. For dynamic or ribbon mics, phantom voltage is not required and should be
switched OFF.
NOTE 1: Operating this switch (On or Off) causes large voltage swings to occur
at the input of the mic preamp. Care should be taken to insure that the channel
is muted or the main faders are pulled down to prevent this POP from getting to
someone’s ears.
Line Input Jack
Line-level signals, balanced or unbalanced, may be brought into the input channel
through this 1/4” TRS jack. The LINE switch (front panel) must be pressed for this jack
to be active. The XLR jack is normaled to the switching contacts of this jack. If nothing
is plugged into the jack, a padded XLR signal is available to the channel when the LINE
switch is depressed. This allows the LINE switch to perform a dual function: XLR pad if
nothing is plugged into the Line jack, or XLR (Mic)/Line input selection if the jack is
being used.
Tip is Positive Input, Ring is Negative Input, Sleeve is Chassis Ground
Input impedance is 20K
balanced
XLR (Mic) Input Jack
This balanced, female XLR accepts a low-impedance microphone signal or a line-level
signal, depending on the position of the LINE INPUT switch on the front panel.
Pin-2 is Positive Input, Pin-3 is Negative Input, Pin-1 is Chassis Ground
Input impedance is 4K
balanced
Chan Insert Jack
This switching 1/4” TRS jack allows an external signal processor to be inserted into the
signal path of the channel. The tip carries the SEND signal from the channel, and the
ring carries the RETURN signal back to the channel. The insert-send point is located
directly after the Lo-Cut filter on the channel, and the return comes back into the
channel at the top of the EQ section.
Tip is Send, Ring is Return, Sleeve is Audio Ground
Send (output) impedance is 50
Return (input) impedance is 5K
Nominal Operating Level= +4 dBu
NOTE: To avoid any degradation of the mixer's channel signal, any processing gear
patched into the insert path should have a low impedance output (<100) and must be
capable of cleanly driving a 2K
load to +21 dBu.
DIRECT OUT Jack
The channel signal can be brought out of the console via the direct out jack. The signal
that appears at this jack is normally post fader. There is an internal option for making it
pre fader.
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