Studio Technologies 770 - Manual (Page 35)

Model 770 User Guide Issue 1, October 1997
Studio Technologies, Inc. Page 35
Model 770
interface will return to its on-hook state
after a few seconds. Momentarily pressing
the switch to the position labeled HANG
UP disconnects the interface from the
telephone line. Note that in the standard
audio mode this switch is not active be-
cause the standard audio mode places
the interface permanently in what is effec-
tively the off-hook condition.
A second switch controls the audio routing
through the interface. In the switch’s
center position, labeled SEND, the send
audio source (selected using the DIP
switches on the back panel) is sent out
the interface. The send level has been
internally set to give the highest signal
level possible, without overloading con-
nected equipment. In the switch’s left
position, labeled PGM, audio received by
the interface is connected to the program
audio bus. In the switch’s right position,
labeled INT, audio received by the inter-
face is connected to the interrupt audio
bus. A receive level trim potentiometer is
provide, allowing the receive audio level
to be adjusted over a ±8dB range. A quiet
signal can be boosted, or a “hot” signal
can be attenuated.
IFB Monitor Output
A separate monitor output is provided by
the IFB section, independent of the moni-
tor section’s monitor output. This allows
the IFB signal to be monitored at, essen-
tially, all times, minimizing the chance of
important cues being missed. Only when
the gooseneck microphone is active will
the IFB monitor output be muted to pre-
vent acoustic feedback. To use the IFB
monitor output is simple, just set the rotary
level control to the give the desired output
level.
Auto Answer Function
When the mode of the telco interface is
set for telephone line, and auto answer
has not been disabled, the interface will
“answer” a call after the detection of two
ringing voltage cycles. Waiting for two
complete ring cycles was specifically
selected so that a calling party will have a
chance to hear audible call progress tones
provide by their communications provider.
The telco interface’s circuitry is capable of
answering in a fraction of a ring cycle, but
this can be confusing to callers, especially
Figure 15. Detail of front panel showing telco
interface