Studio Technologies M233-01151 - Manual (Page 20)

Issue 5, November 2014 Model 233 User Guide
Page 20 Studio Technologies, Inc.
Headphone Source Selection
Switch assembly SW2 is used to configure
the sources that are routed to the stereo
headphone output. Five headphone sourc-
es are available: line input 1, line input 2,
intercom channel 1, intercom channel 2,
and sidetone. Each of these sources can
be assigned to the left, right, or both the
left and right channels of the stereo head-
phone output.
The line inputs are interfaced using two
connectors also located on the back panel.
Associated with line inputs 1 and 2 are
level trim potentiometers. They are provid-
ed so that audio sources with a wide range
of nominal levels can be effectively used as
cue sources. Please refer to the Advanced
Operation section of this user guide for
details on using the trim pots.
Audio associated with intercom channels
1 and 2 is provided by way of the intercom
interface whose connector is also located
on the back panel. Two trim pots are as-
sociated with the intercom channels. They
allow adjustment of the intercom sidetone
(null) level. This impacts the amount of
talkback audio signal that is returned to
a headphone output when a talkback-to-
intercom function is active.
The sidetone audio source comes from
the output of the compressor circuit as-
sociated with the microphone preamplifier.
This allows an announcer or other Model
233 user to receive a confirmation signal
of what is coming out of the main, and if
configured, talkback outputs.
As previously discussed, each of the avail-
able input sources can be assigned to
the headphone output’s left channel, right
channel, or both the left and right chan-
nels. The Model 233’s circuitry allows any
combination of input assignments to be
Figure 6. Left and right channel headphone
source selection settings
made. For example, consider the situation
where a single-channel intercom line, with
audio present only on pin 3, is connected.
In this case it may be desirable to assign
this intercom audio source to both the left
and right channels. This would entail set-
ting switches SW2-4 and SW2-9 to their on
positions. All other switches would remain
in their off positions.
A more complex application might have
a broadcast-type 2-channel IFB circuit
connected to the intercom input and a
line-level audio signal from a golf event