PIC-4704, MA-704 & AX-704 IFB SYSTEM 1-1
OPERATION
INTRODUCTION
During the production of a program for transmission or recording, a director or
producer frequently needs to cue the performing talent. This is done using
Interrupt FoldBack (IFB), a type of closed-circuit intercom for sending program
and cue audio on “IFB” lines for the talent to monitor. The IFB line carries three
signals: program audio, cue audio, and the dip or mute control. See the signal
flow diagram below (Figure 1-1). Electronic control allows the director to
interrupt the program signal when addressing the talent. IFB communications
are one-way only from an access location to the selected talent position.
Figure 1-1: Audio Control Paths
Clear-Com’s new stand-alone IFB components provide high performance,
cost-effective answers for applications where regular intercom functions are not
also required, or where space contraints require compact, versatile packaging.
The simplest stand-alone system consists of a PIC-4704, an MA-704, a PS-702
for power, and one to four TR-50 talent receivers. This system will permit cuing
of one to four talent positions from only one access location.
Note: Throughout this manual, “access location” refers to the physical place
someone needs to cue the talent from. “Talent position” refers to the
individual “talent” cue channels.
DESCRIPTION
Clear-Com’s stand-alone series of IFB components offers two types of talent
access station. The MA-704 has a socket for a gooseneck microphone and a
pre-amplifier with line-level output. It provides access to four talent positions.
Each AX-704 allows access, from the same location, to an additional group of
four talent positions; it requires an external line-level signal for its cue audio
source. The MA-704’s cue audio and ALL control signals will feed up to 24
AX-704s, so that only one MA-704 is required at each access location. Each talent
position may be accessed independently, or simultaneously with any other(s).
The ALL button on the MA-704 simultaneously accesses all talent positions of
the MA-704 and each AX-704 extension unit fed from that MA-704.
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