Studio Technologies 240 - Manual (Page 22)

Issue 1, August 2013 Model 240 User Guide
Page 22 Studio Technologies, Inc.
The headphone monaural mode is specifi-
cally provided so that a flexible headphone
mix can be easily created. If mono has
been enabled, the three front-panel level
controls are used as a phones source
mixer. A signal assigned to the left channel
can have its level adjusted using the con-
trol on the far left. A signal assigned to the
right channel will have its level adjusted
using the control in the center. If sidetone
is enabled, the control on the far right will
adjust the amount of signal associated
with the microphone input to be sent to
the headphone output.
Notes on Sidetone Operation
As previously covered in this guide, the
sidetone function can be enabled. Side-
tone is defined as the user’s own voice
signal being returned to them as a head-
phone source. This helps the user be more
effective as they can be aware of what they
are saying into the microphone. Depending
on how it was configured, sidetone audio
will be sent to the left headphone output,
the right headphone output, or both the
left and right headphone outputs. When
the sidetone level control is in its fully
counterclockwise position the sidetone
signal will always be fully muted.
Astute readers will realize that sidetone
audio can also be provided from the inter-
com cue sources during Model 240 talk to
intercom activity. This “passive” sidetone is
created in the intercom interface’s analog
talk/listen hybrid sidetone (null) circuit. Trim
pots allow the intercom sidetone level to
be adjusted over a limited range. To get
maximum performance when either or
both intercom channels are used as a cue
source one simple calibration process may
need to be performed. This involves ad-
justing the sidetone (null) trim pots to their
fully counterclockwise positions, providing
minimum sidetone level. This will reduce
the level “build up” that would occur when
both the main and the intercom sidetone
audio signals are sent to the headphone
output. The goal is for the sidetone level to
remain as constant as possible, no matter
what function — talk-to-main output or talk-
to-main-output-and-intercom — is active.
The Model 240’s level controls have a
mechanical step (detent) that is located
at the halfway (50%) position of their
rotation range. This is intended to serve
as an aid to Model 240 users. In an ideal
installation, setting the far left and center
controls to their detent position will result
in a comfortable headphone output level.
The user, in response to a changing oper-
ating environment, can then move the con-
trols to get more or less level as desired.
The detent position will always remain as
a useful reference point. To achieve this
condition the audio level on the connected
line inputs may have to be calibrated as
required. This is somewhat counter to the
usual mentality of just providing the user
with whatever level comes up by default.
Spending a few extra minutes “trimming”
the audio levels can result in much happier
and more productive personnel. As previ-
ously mentioned, a level trim potentiometer
is associated with each line input. If either
or both of the line inputs is assigned to the
headphone output these trim pots may be
helpful in achieving the desired adjustment
range of the two front-panel level controls.
Refer to the Advanced Operation section
of this guide for details.
Headphone Output Level
Typically the headphone output level will
not be impacted by talk function activ-
ity. But a configurable option allows the
headphone output level to be reduced in
level (“dimmed”) by 20 dB whenever a talk