Studio Technologies 230 2008 - Manual (Page 48)

Issue 7, October 2008 Model 230 User Guide
Page 48 Studio Technologies, Inc.
The relay provides two “form-C” contacts,
each consisting of a common, normally
open (not shorted), and normally closed
(shorted) connection. Obviously the two
form-C contacts change state in unison;
two independent relay functions are not
provided. These relay contacts are ac-
cessible on the Model 230’s main printed
circuit board assembly by way of two 3-
position header connectors. The contacts
are titled A and B, but there is no signifi-
cance between the two. With both headers
pin 1 is normally closed, pin 2 is common,
and pin 3 is normally open. For additional
details on connecting to the 3-position
headers please refer to the Additional
Connectors section in the Technical Notes
area of this user guide.
Main Output Source Selection
From the factory the Model 230 is config-
ured so that the output of the microphone
preamplifier is the audio source for the
main output. For most on-air applications
this is the desired source. It will provide
the most natural audio quality with the
potential for a large amount of dynamic
range. The output of the microphone pre-
amplifier is also connected to the input of
the compressor circuit. The output of the
compressor circuit supplies audio to the
talkback functions. Controlling the dy-
namic range of the talkback audio signals
can minimize the chance of cable cross-
talk and equipment overload in non-on-air
signal chains.
But in the audio business exceptions
often turn out to be the rule. In some very
special applications it may be desirable
for the output of the compressor circuit to
be routed to the main output. This could
be especially true when the Model 230’s
system mode is selected for production 2
and the main output is serving as an addi-
tional talkback function. A “hidden” feature
allows the main output’s audio source to
be changed. From the factory, the output
of the microphone preamp is routed to
the main output by way of a 0 ohm “jump-
er” soldered into the Model 230’s printed
circuit board assembly. An alternate
component location is also included to
allow the output of the compressor to
serve as the source. With these simple
provisions a qualified technician can move
the jumper and achieve the desired au-
dio-source change. As the process does
require soldering and “board level” com-
ponent work, electing to make the change
must be approached with care. Contact
the factory for additional details.
Additional Line-Level Output
The two talkback buttons on the Model
230 allow talkback audio to be routed
to one line-level output and one or two
channels associated with an intercom
line. However, there may be applica-
tions where it would be helpful to have a
second line-level output. The Model 230
has made provision to accomplish this
using an optional line output card. This
card, available from Studio Technologies
and purchased separately (part number
31086), is mounted into a spare connector
location located on the Model 230’s back
panel. Audio “drive” for the card comes
from the circuitry associated with the
talkback-to-intercom functions. Due to this
circuitry’s design, the nominal output level
of the line output card is –10 dBu. Two
3-position header connectors, located
on the Model 230’s main printed circuit
board assembly, provide access to talk-
back-to-intercom channel 1 and channel 2
audio signals.