Studio Technologies 204 User manual

Copyright © 2018 by Studio Technologies, Inc., all rights reserved
www.studio-tech.com
User Guide
Issue 2, October 2018
This User Guide is applicable for serial numbers
M204-00151 to 00500 with application firmware 1.2 and later
and STcontroller application version 1.07.00 and later.
50639-1018, Issue 2
Model 204 Announcer’s Console

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Model 204 User Guide Issue 2, October 2018
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MODEL 204
ANNOUNCER’S CONSOLE
Table of Contents
Revision History ........................................................... 4
Introduction ................................................................... 5
Getting Started ............................................................. 10
Operation ...................................................................... 19
Technical Notes ............................................................ 24
Specifications ............................................................... 28
Appendix A: Model 204 Block Diagram ........................ 29

Issue 2, October 2018 Model 204 User Guide
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MODEL 204
ANNOUNCER’S CONSOLE
Revision History
Issue 2, October 2018:
• Documents addition of the Push to Mute/Tap to Latch main button operating mode.
Issue 1, May 2018:
• Initial release.

Model 204 User Guide Issue 2, October 2018
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MODEL 204
ANNOUNCER’S CONSOLE
Introduction
The Model 204 Announcer’s Console of-
fers a unique combination of analog and
digital audio resources for use in broadcast
sports, eSports, live event, entertainment,
and streaming broadcast applications. The
unit is housed in a compact, rugged steel
enclosure that’s intended for table-top
use. Calling the Model 204 “cute” or “cool”
would be accurate; its nicely proportioned
but diminutive size makes it ideal for use
in space-constrained locations. The Model
204 supports Dante® audio-over-Ethernet
digital media technology with AES67 com-
patibility for integration into contemporary
applications. The unit is extremely simple
to deploy, is “pro” quality throughout, and
provides an intuitive user experience.
The Model 204’s audio quality is excellent,
with low distortion, low noise, and ample
headroom. Careful circuit design and
rugged components ensure long, reliable
operation.
The Model 204 integrates directly into both
Dante audio-over-Ethernet and standard
analog audio environments. With just a
Power-over-Ethernet (PoE) connection, a
microphone, and a pair of headphones or
an earpiece, a complete broadcast on-air
position can be created. And by using the
Model 204’s microphone output a direct
connection to an analog microphone-level
input on an associated camera, remote I/O
interface, or audio console can be support-
ed. Two remote control inputs allow exter-
nal switches or contact closures to activate
the main and talkback button functions.
Model 204 operating features are config-
ured using the STcontroller software ap-
plication. An extensive set of parameters
allows the unit’s functions to be tailored
to meet the needs of many applications.
STcontroller, compatible with version 7 and
later of the Windows® operating system, is
a fast and simple means of confirming and
revising the unit’s operating parameters.
Applications
The Model 204 on its own can provide an
“all-Dante” solution for one on-air talent
location. A wide range of applications can
be supported, including sports and enter-
tainment TV and radio events, streaming
broadcasts, corporate and government AV
installations, and post-production facilities.
The unit’s small size makes it ideal for live-
sports applications, such as basketball,
where physical space for personnel is very
limited. Four Dante receiver (audio input)
channels supply the user with their talent
cue (IFB) signals. Should the cue signal
be “mix-minus” an integrated sidetone
Figure 1. Model 204 Announcer’s Console front
and rear views

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ANNOUNCER’S CONSOLE
function can provide the user with a micro-
phone confidence signal. Two Dante audio
output channels, one designated as main
and the other as talkback, are routed via
an associated local-area network (LAN) to
inputs on Dante-compatible devices. Two
pushbutton switches, main and talkback,
provide the user with direct control over
audio routing. The audio switching is per-
formed in the digital domain and is virtually
“click-free.”
By providing the main audio signal in two
forms, Dante digital audio and analog
microphone level, the Model 204 makes
integration into a wide range of on-air
environments easy to accomplish. The
talkback audio channel is available as a
Dante output channel which makes routing
to an input on a variety of devices, such as
matrix intercom systems, audio consoles,
and monitor loudspeaker systems, simple
and flexible.
Some applications may benefit from not
utilizing the Model 204’s Dante main out-
put channel. This typically won’t be an is-
sue of inadequate audio quality but rather
a need to match work-flow requirements.
For example, for lip-sync or transmission
purposes it may be optimal to have the
on-air audio transported as an embedded
signal along with the associated camera
video. Alternately, all on-air audio sources
may need to connect to inputs on an audio
console or console-related I/O unit. Sup-
porting these scenarios is not a problem
as the Model 204 supplies a microphone
output connection that’s specifically intend-
ed for this purpose. Simply connect the
unit’s microphone output connection to the
desired analog input, such as the mic/line
input on an ENG-style camera—that’s it!
The circuitry associated with the Model
204’s analog microphone output is very
simple, essentially a passive path that
routes a signal connected to the micro-
phone input connector directly to the
microphone output connector. A solid-state
circuit, in series with the mic in-to-mic out
path, allows muting of the signal on the
microphone output connector whenever
the Dante main output channel is muted.
Having both the Dante main output and the
microphone outputs work in tandem can
be a valuable resource, allowing one to
serve as the primary on-air signal source
while the other serves as the backup.
Setup and Operation
Set up, configuration, and operation of
the Model 204 is simple. An etherCON®
RJ45 jack is used to interconnect with a
standard twisted-pair Ethernet port associ-
ated with a PoE-enabled network switch.
This connection provides both power and
bidirectional digital audio. A broadcast
headset or handheld (“stick”) microphone
can be directly connected to the unit’s
3-pin XLR mic input connector. The input
is compatible with dynamic or condenser
microphones. The integrated P48 phan-
tom power source provides support for a
wide range of condenser microphones.
A 3-pin XLR microphone output connec-
tor provides a “direct mic out” function
for integration with microphone inputs on
related devices. Stereo headphones, the
headphone connections from a stereo or
monaural headset, or even a monaural
earpiece can be connected to the phones
output jack. External switches or contact
closures can be connected to the Model
204’s remote control inputs to allow ac-
tivation of the main and talkback button
functions. The STcontroller software appli-
cation is used to configure the wide range

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MODEL 204
ANNOUNCER’S CONSOLE
of Model 204 operating parameters. This
allows the unit’s performance to be opti-
mized to meet the needs of specific
applications.
The user is presented with two pushbutton
switches and three push-in/push-out rotary
level potentiometers. This makes it easy to
control the status of the main and talkback
outputs as well as adjusting the signals
that are sent to the headphone channels.
Ethernet Data and PoE
The Model 204 connects to a local area
network (LAN) by way of a standard 100
Mb/s twisted-pair Ethernet interface. The
physical 100BASE-TX interconnection
is made by way of a Neutrik® etherCON
RJ45 connector. While compatible with
standard RJ45 plugs, etherCON allows a
ruggedized and locking interconnection for
harsh or high-reliability environments.
The Model 204’s operating power is pro-
vided by way of the Ethernet interface
using the 802.3af Power-over-Ethernet
(PoE) standard. This allows fast and ef-
ficient interconnection with the associated
data network. To support PoE power man-
agement, the Model 204’s PoE interface
enumerates (reports) to the power sourc-
ing equipment (PSE) that it’s a class 2 (low
power) device. If a PoE-enabled Ethernet
port can’t be provided by the associated
Ethernet switch a low-cost PoE midspan
power injector can be utilized.
Dante Audio-over-Ethernet
Audio data is sent to and received from
the Model 204 using the Dante audio-over-
Ethernet media networking technology.
As a Dante-compliant device, the Model
204’s two Dante transmitter (audio output)
channels and four Dante receiver (audio
input) channels can be assigned (routed
or “subscribed”) to other devices using the
Dante Controller software application. The
Dante transmitter and receiver channels
are limited to supporting four Dante flows,
two in each direction. The digital audio’s
bit depth is up to 24 with a sampling rate of
44.1 or 48 kHz. Two bi-color LEDs provide
an indication of the Dante connection sta-
tus. An additional LED displays the status
of the associated Ethernet connection.
The Model 204 is compatible with the
AES67 interoperability standard. In this
mode the two transmitter (output) channels
will function in multicast; unicast is not sup-
ported. In addition, the unit is compatible
with the Dante Domain Manager™ (DDM)
software application.
Audio Quality
The Model 204’s audio performance
is completely “pro.” A low-noise, wide
dynamic-range microphone preamplifier
and associated voltage-controlled-
amplifier (VCA) dynamics controller (com-
pressor) ensures that mic input audio qual-
ity is preserved while minimizing the chance
of signal overload. The output of the micro-
phone preamp and compressor is routed
to an analog-to-digital conversion (ADC)
section that supports sampling rates of 44.1
and 48 kHz with a bit depth of up to 24.
The audio signal, now in the digital domain,
routes through a 32-bit microprocessor and
on to the Dante interface section where it is
packetized and prepared for transport over
Ethernet.
Audio input signals arrive via the four Dante
receiver channels and pass into the Model
204’s microprocessor. The supported sam-
pling rates are 44.1 and 48 kHz with a bit
depth of up to 24. Channel routing, head-
phone level control, and sidetone creation
are performed within the digital domain.

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This provides flexibility, allows precise
control, and keeps the three level poten-
tiometers from having to directly handle
analog audio signals. The audio channels
destined for the phones outputs are sent
to a high-performance digital-to-analog
converter and then on to robust driver cir-
cuitry. High signal levels can be provided
to a variety of headsets, headphones, and
earpieces.
Configuration Flexibility
The Model 204 can be configured to meet
the needs of specific applications and user
preferences. All configuration choices are
performed using the STcontroller software
application which is compatible with ver-
sion 7 and later of the Windows operating
systems. There are no mechanical switch
settings or button-press sequences re-
quired to configure how the unit functions.
Selectable parameters include microphone
preamplifier gain, P48 phantom power
on/off, button operation, remote control
inputs, headphone output mode, sidetone
operation, and overall unit operation. The
gain of the microphone preamplifier can
be selected from among four choices. This
allows the Model 204 to match the out-
put sensitivity of a range of handheld and
headset-associated microphones. A low-
noise source of P48 phantom power can
be enabled if required to support condens-
er (capacitor) microphones.
The main and talkback pushbutton switch-
es can be individually configured. The
main button can be selected to operate
from among five modes while the talkback
button can be selected from among three.
These choices allow the Model 204’s
operation to be tailored to meet the spe-
cific needs of many applications. As an
example, for on-air sports applications the
main button would typically be configured
to provide a push to mute (cough) function.
The microphone signal on the Dante main
output channel and the microphone output
connector would remain active unless the
talent needs to momentarily disable it. The
talkback button would most likely be set to
the push to talk mode as its use would be
intermittent.
The Model 204 provides two remote con-
trol inputs. Configuration choices allow
these to be assigned to work in paral-
lel with the main or talkback pushbutton
switches. In this way activation of a remote
control input will emulate a user pressing
its associated pushbutton switch.
The audio sources and the way in which
they are assigned to the headphone output
channels can be configured from among
five choices. These unique choices allow
almost any required headphone monitor-
ing situation to be implemented. Whether
for use in on-air sports, an awards show
broadcast, or as a production support tool,
the Model 204 should be able to achieve
the desired configuration.
Following the mode number is an abbrevi-
ated description of what signal or signals
are assigned to the three potentiometers
(pots) and on to the two headphone output
channels. The potentiometers are labeled
A, B, and C, as can be seen in Figure 1
of this guide. The format would equate to
Mode x – pot A/pot B/pot C where x equals
the mode number.
• Mode 1 – Ch1L/Ch2R/SidetoneLR:
Provided for broadcast applications
where two monaural channels of tal-
ent cueing audio (“IFB”) need to be
independently sent to the left and right
headphone output channels. It would be
common for program audio with director

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MODEL 204
ANNOUNCER’S CONSOLE
interrupt to enter the Model 204 by way
of Dante input (receiver) channel 1 and
be sent to the left headphone output.
Program-only audio, entering the unit by
way of Dante input channel 2, would be
sent to the right headphone output. Pots
A and B are used to adjust the level of
those signals. Pot C is used for the sid-
etone function where microphone audio
is sent to both the left and right channels
of the headphone output.
• Mode 2 – Ch1LCh2R/BalanceLR/
SidetoneLR: Intended for applications
where a stereo signal enters the Model
204 by way of Dante inputs 1 and 2 and
is routed in stereo to the left and right
channels of the headphone output. In
this mode pot A controls the overall level
of this stereo signal and pot B controls
its left/right level balance. Pot C is used
by the sidetone function.
• Mode 3 – Ch1LCh2R/Ch3LCh4R/
SidetoneLR: Allows two stereo signals
to be routed as stereo pairs to the two
headphone output channels. In this
mode pot A adjusts the level of the
stereo pair entering the unit by way of
Dante inputs 1 and 2 while pot B adjusts
the level of the stereo pair entering on
Dante inputs 3 and 4. Pot C is used by
the sidetone function.
• Mode 4 – Ch1L/Ch2R/Ch3LCh4R:
Allows two monaural input signals to
be independently routed to the left and
right headphone output channels. These
audio signals would enter the Model 204
by way of Dante input channels 1 and 2.
Pots A and B are used to control the lev-
els of the signals as they are sent to the
left and right headphone output chan-
nels. A stereo input signal, entering the
unit by way of Dante inputs 3 and 4, are
routed to the left and right headphone
outputs. This stereo pair has its level
controlled by pot C.
• Mode 5 – Ch1LR/Ch2LR/Ch3LCh4R:
Allows two monaural input audio chan-
nels to be sent to both the left and right
headphone output channels. Dante
inputs 1 and 2 are used to bring these
audio signals into the Model 204. Pots
A and B are used to control the level of
the signals as they are sent to the head-
phone output channels. Pot C is used to
control the level of a stereo input signal
as it is routed to the left and right chan-
nels of the headphone output. This ste-
reo pair enters the unit by way of Dante
inputs 3 and 4.
The integrated sidetone function can be
configured to operate from among four
choices. This allows audio associated with
the microphone input and microphone
preamplifier to be returned to the head-
phone output. This is important as different
applications may provide a “full mix” or a
“mix-minus” talent cue signal. If a full mix
cue signal is provided then sidetone audio
will not be needed and the function can be
disabled. In the case where a mix-minus
signal is present, providing the user with
sidetone at the appropriate time(s) can
be an important means of confirming the
signal that’s coming from the connected
microphone.
The headphone gain range configura-
tion helps to provide an optimized audio
level to Model 204 users. The appropriate
setting will depend on the specific audio
sources provided to the unit as well as
user preference.

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Three system modes select the overall
way in which the Model 204 functions. The
on-air mode is optimized for applications
where users will be on-air talent that must
maintain strict separation between on-air
and production audio channels. Other
applications will benefit from the two avail-
able production modes.
Future Capabilities and
Firmware Updating
The Model 204 was designed so that
its capabilities and performance can be
enhanced in the future. A USB connector,
located on the unit’s main circuit board
(underneath the unit’s cover), allows the
application firmware (embedded software)
to be updated using a USB flash drive.
The Model 204 uses the Audinate Ultimo™
integrated circuit to implement the Dante
interface. The firmware in this integrated
circuit can be updated via the Ethernet
connection, helping to ensure that its
capabilities remain up to date.
Getting Started
What’s Included
Included in the shipping carton are a
Model 204 Announcer’s Console and a
printed copy of this guide. As a device that
is Power-over-Ethernet (PoE) powered, no
external power source is provided. In most
applications an Ethernet switch with PoE
capability will be utilized. If that’s not avail-
able a PoE midspan power injector can be
used.
Connections
In this section signal interconnections will
be made using the five connectors located
on the back of the Model 204’s enclosure.
An Ethernet data connection with Power-
over-Ethernet (PoE) capability will be
made using either a standard RJ45 patch
cable or an etherCON protected RJ45
plug. A microphone will be connected us-
ing a cable-mounted 3-pin male XLR con-
nector. A set of headphones or an earpiece
will be connected by way of a ¼-inch plug.
If desired, the Model 204’s microphone-
level output may be interfaced with other
equipment using a cable terminated with
a standard 3-pin female XLR connector.
Special applications may utilize the two
remote control inputs that are accessible
using a 3.5 mm 3-conductor jack.
Ethernet Connection with PoE
A 100BASE-TX Ethernet connection that
supports Power-over-Ethernet (PoE) is
required for Model 204 operation. This one
connection will provide both the Ethernet
data interface and power for the Model
204’s circuitry. A 10BASE-T connection is
not sufficient and a 1000BASE-T (“GigE”)
connection is not supported unless it can
automatically “fall back” to 100BASE-TX
operation. The Model 204 supports Ether-
net switch power management, enumerat-
ing itself as a PoE class 2 device.
The Ethernet connection is made by way
of a Neutrik etherCON protected RJ45
connector that is located on the back of
the Model 204’s enclosure. This allows
connection by way of a cable-mounted
etherCON connector or a standard RJ45
plug. The Model 204’s Ethernet interface
supports auto MDI/MDI-X so that a “cross-
over” or “reversing” cable will never be
required.
Ethernet Connection without PoE
As previously discussed in this guide, the
Model 204 was designed such that the
Ethernet connection will provide both data

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MODEL 204
ANNOUNCER’S CONSOLE
and Power-over-Ethernet (PoE) power.
There may be situations where the as-
sociated Ethernet switch does not provide
PoE power. In such cases an external PoE
midspan power injector can be used. If the
selected midspan power injector is 802.3af-
compatible it should function correctly.
Midspan units are available from a variety
of sources, including many online retailers.
Microphone Input
The Model 204 provides a 3-pin female
XLR connector that allows a balanced
dynamic or phantom powered condenser
powered microphone to be connected. The
microphone can be a standalone handheld
(“stick”) type or can be part of a broadcast-
style headset. The Model 204’s microphone
input is directly compatible with balanced
dynamic or P48 phantom powered micro-
phones. A microphone should be connected
such that its associated XLR connector has
pin 1 as common, pin 2 as signal high (+),
and pin 3 as signal low (–). A configura-
tion setting allows the P48 phantom power
source to be enabled or disabled as de-
sired. Details on configuration settings will
be described later in this guide.
While the Model 204 provides an excellent
source of P48 phantom power, it’s possible
that an input on an associated piece of
equipment is already providing microphone
power. This could be connected to the
Model 204 by way of the microphone output
connector. This would not create a problem
since the circuitry that connects audio from
the Model 204’s microphone output con-
nector to the Model 204’s microphone input
connector will pass this microphone power
through without interruption. This situation
could be relevant when the Model 204’s
microphone output connector is interfaced
with the microphone input on a broadcast
camera, audio console, microphone mixer,
or similar equipment. Inputs on these de-
vices would typically offer phantom power
which in some cases may have been
enabled.
Headphone Output
The Model 204 provides a 2-channel
headphone output interfaced by way of a
3-conductor ¼-inch phone jack. Devices
such as stereo headphones or stereo
(“dual-muff”) broadcast-style headsets can
be directly connected using a 3-conductor
¼-inch plug. Following the usual conven-
tion the left channel should be terminated
on the tip lead, the right channel on the
ring lead, and common on the sleeve lead.
It’s also possible to use a monaural
(“single-muff”) headset or broadcast-type
single earbud but in these cases care must
be taken. If a 3-conductor ¼-inch plug is
used by a device it should be wired to the
tip and sleeve leads; the plug’s ring lead
should be left unconnected. But it’s also
possible that the monaural device will
be terminated on a 2-conductor (“tip and
sleeve”) plug. When the plug is inserted
into the Model 204’s headphone jack the
Model 204’s right headphone output chan-
nel will be shorted; the ring lead will be
directly connected to the sleeve lead. This
can lead to stress on the right channel
headphone output circuitry as well as extra
current draw. To prevent this undesirable
condition ensure that no input audio signal
is routed to the right headphone output
channel. Refer to the Configuration section
later in this guide for details on setting the
headphone audio routing to best accom-
plish this condition.
Microphone Output
A 3-pin male XLR connector provides a
microphone-level output that’s directly re-
lated to the microphone input. Technically

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ANNOUNCER’S CONSOLE
the output is identical to the signal that’s
connected to the microphone input but with
a solid-state muting circuit in series with
the interconnection. When the Model 204’s
Dante main output channel is active the
microphone signal will also pass through to
the Model 204’s microphone output connec-
tor. Whenever the Dante main output chan-
nel is muted the microphone signal does
not pass through to the microphone output
connector; it is muted in an essentially
click-free manner. Refer to Appendix A for a
block diagram of the microphone input and
microphone output circuitry.
The microphone output can be connected
to balanced (differential) analog micro-
phone-level inputs on a variety of devices.
This includes microphone input connec-
tions on remote I/O interfaces associated
with a networked audio console. An ex-
ample of such an interface would be the
Calrec® Hydra2®. The mic inputs on these
devices typically offer microphone power,
high-quality amplification, and conversion
to the digital domain. The output signals of
the interface’s pre-amp channels are trans-
ported to the main electronics or console
surface using a fiber optic interface. In this
type of application the Model 204’s Dante
main output channel would not be used or
would only be used as a backup path.
No preamplifier or other active circuitry
impacts the path from the Model 204’s
microphone input connector to the Model
204’s microphone output connector. But the
signal does pass through a 200 ohm resis-
tor in each “leg” (pin 2 and pin 3) along with
connecting to a solid-state relay contact.
The result is that the source impedance of
a connected microphone will be 400 ohms
greater when presented to the microphone
output connector. This will slightly raise the
theoretical noise floor of the microphone
signal vis-à-vis a directly connected mi-
crophone signal but shouldn’t impact any
real-world applications.
Remote Control Inputs
Provision has been made to allow external
switches or contact closures to mimic
operation of the main and talkback push-
button switches. The exact functioning
of the two remote control inputs is deter-
mined by configuration settings, details
of which are discussed later in this guide.
A 3.5 mm 3-conductor jack is located on
the Model 204’s back panel and provides
access to the two remote control inputs.
The input circuitry is “active low,” with
3.4 k ohm resistors connected to +3.3 volts
DC to act as input “pull ups.” (In addition,
a combination of resistors and capacitors
provide ESD protection, minimizing the
chance of damage due to static discharge
or other extraneous signals.) A current flow
of less than one milliampere is required for
a remote control input to be recognized as
active.
Prepare the interconnecting cable and
associated 3.5 mm 3-conductor plug to
reflect that the tip lead is used by remote
control input 1, the ring lead by remote
control input 2, and the sleeve lead is the
connection to common.
Dante Configuration
For audio to pass to and from the Model
204 requires that several Dante-related
parameters be configured. These configu-
ration settings will be stored in non-volatile
memory within the Model 204’s circuitry.
Configuration will typically be done with
the Dante Controller software application
which is available for download free of
charge at www.audinate.com. Versions of
Dante Controller are available to support
Windows and OS X® operating systems.

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The Model 204 uses the Ultimo 4-input/
4-output integrated circuit to implement
the Dante functionality. The Model 204
can also be configured to meet the re-
quirements of the AES67 standard. This
requires a setting to be enabled within the
Device Info section of the Dante Controller
application.
The two Dante transmitter (Tx) channels
associated with the Model 204’s Dante in-
terface must be assigned to the desired re-
ceiver channels on associated equipment.
This achieves routing the Model 204’s two
output audio channels to the device (or
devices) that will be “listening” to them.
Within Dante Controller a “subscription” is
the term used for routing a transmitter flow
(a group of output channels) to a receiver
flow (a group of input channels). The num-
ber of transmitter flows associated with an
Ultimo integrated circuit is limited to two.
These can either be unicast, multicast, or a
combination of the two. If the Model 204’s
transmitter channels need to be routed to
more than two flows it’s possible that an
intermediary device with enhanced flow
capability, such as the Studio Technologies
Model 5422 Dante Intercom Audio Engine,
can be used to “repeat” the signals.
The desired audio sources need to be
routed to the receiver (Rx) channels as-
sociated with the Model 204’s Dante audio
inputs. The unit provides four audio input
channels. The number utilized will de-
pend on the specific application. Following
the unit’s headphone source and routing
configuration selection these audio signals
will be sent to the Model 204’s 2-channel
headphone output.
The Model 204 supports audio sample
rates of 44.1 and 48 kHz with no pull-up/
pull-down values available. In most cases
it’s anticipated that the default rate of 48
KHz will be appropriate. While technically
the Model 204 can serve as a clock master
for a Dante network (as can all Dante-
enabled devices) in virtually all cases the
unit will be configured to receive “sync”
from another device.
The Model 204 has a default Dante device
name of ST-M204 along with a unique suf-
fix. The suffix identifies the specific Model
204 that is being configured. The suffix’s
actual alpha and/or numeric characters
relate to the MAC address of the unit’s Ulti-
mo integrated circuit. The two Dante trans-
mitter (Tx) audio output channels have
default names of Main and Talkback. The
four Dante receiver (Rx) audio input chan-
nels have default names of Headphone
Ch1, Headphone Ch2, Headphone Ch3,
and Headphone Ch4. Using Dante Con-
troller the default device name and chan-
nel names can be revised as appropriate
for the specific application.
Model 204 Configuration
The STcontroller software application is
used to configure the way in which the
Model 204 functions. No DIP switch set-
tings or other local actions are used to
configure the unit. This makes it imperative
that STcontroller be available for conve-
nient use in a personal computer that’s
connected to the related LAN.
The configurable functions include:
• P48 phantom power on/off status
• Microphone input gain
• Headphone audio sources and routing
• Headphone gain range and minimum
level
• Sidetone

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ANNOUNCER’S CONSOLE
• Main and talkback button operating
modes
• System operating mode
• Remote control inputs
• Button backlight intensity
Changes made using STcontroller will be
immediately reflected in the unit’s opera-
tion; no Model 204 “reboot” is required.
Each time a change is made the main and
talkback buttons on the front panel will
momentarily flash orange in a distinctive
pattern to indicate that a command from
STcontroller has been received.
Installing STcontroller
STcontroller is available free of charge on
the Studio Technologies website (www.
studio-tech.com/stcontroller) and is com-
patible with personal computers running
Windows operating systems that are
version 7 and later. STcontroller versions
1.07.00 and later will fully support the Mod-
el 204. If required, download and install
STcontroller onto a designated personal
computer. This personal computer must be
on the same local area network (LAN) and
subnet as the Model 204 unit or units that
are to be configured. Immediately after
starting STcontroller the application will
locate the devices that it can control. The
one or more Model 204 units to be config-
ured will appear in the device list. Use the
Identify command to allow easy recogni-
tion of a specific Model 204 unit. Double-
clicking on a device name will cause the
associated configuration menu to appear.
Review the current configuration and make
any changes that are desired.
P48 Phantom Power
STcontroller allows selection of the on/
off status of the microphone input’s P48
phantom power source. The on/off sta-
tus is displayed by way of an LED, red in
color, located on the back panel adjacent
to the microphone input connector. Select
the status of the P48 source to meet the
needs of the connected microphone. No
problem will occur if an external source of
P12 or P48 phantom power is present on
the connection made to the microphone
output connector. In this case simply turn
off the Model 204’s P48 phantom power
source. The external source of microphone
power will “pass thru” from the microphone
output connector to the microphone input
connector.
Microphone Input Gain
The gain of the Model 204’s microphone
preamplifier can be selected from among
four choices: 35, 43, 52, and 59 dB. The
compressor active LED, orange in color
and visible on the back of the Model 204’s
enclosure adjacent to the microphone
input connector, can act as a guide when
setting the preamp gain. When a voice sig-
nal at a normal level is present on the mi-
crophone input the compressor active LED
should light intermittently. If, for example, it
rarely lights and the gain is set to 43 dB, it
might be a good idea to change the setting
to 52 dB. If the LED is lit fully during nor-
mal talking and the gain is set for 52 or 59
dB, changing it to one of the lower values
might be warranted. There’s no “hard and
fast” rule about which gain setting is ap-
propriate. But unless otherwise indicated,
43 dB is typically a good initial choice.
Headphone Audio Sources and Routing
STcontroller allows selection from among
five headphone audio source and routing
modes. Each mode is distinct and care-
ful selection will help optimize the Model
204’s operation for a range of applications.

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ANNOUNCER’S CONSOLE
Mode 1 – Ch1L/Ch2R/SidetoneLR
Mode 1 is provided for on-air applications
where two independent audio sources need
to be routed separately to the two head-
phone output channels. Dante input (re-
ceiver) channel 1 will be routed to the left
headphone output channel and pot A will
adjust its level. Dante input (receiver) chan-
nel 2 will be routed to the right headphone
output channel and pot B will adjust its level.
Pot C will adjust the level of the sidetone
audio as it is sent to both the left and right
headphone output channels.
Mode 2 – Ch1LCh2R/BalanceLR/Side-
toneLR
Mode 2 is provided for stereo applications
that could include live music events that
are distributed via streaming audio or by
way of an over-the-air broadcast. In these
applications it’s typical to want the user to
have a single potentiometer to simultane-
ously adjust the level of a stereo pair while
a separate potentiometer is used to adjust
the left/right level balance.
When set for mode 2 Dante input chan-
nel 1 will be routed to the left headphone
output channel and Dante input channel 2
will be routed to the right headphone output
channel. Pot A will adjust the overall level
of both headphone output channels. Pot B
will adjust the level balance between the left
and right output channels. Pot C will adjust
the level of the sidetone audio as it is sent
to both the left and right headphone output
channels.
Mode 3 – Ch1LCh2R/Ch3LCh4R/Side-
toneLR
Mode 3 can be useful in applications where
two stereo signals need to be provided to
the user on the left and right headphone
output channels. In this mode Dante input
channels 1 and 2 are routed to the left and
right channels of the headphone output.
Pot A adjusts the level of this stereo pair.
Dante input channels 3 and 4 are also
routed to the left and right channels of the
headphone output. Pot B adjusts the level
of this stereo pair as it is sent to the head-
phone output channels. Pot C will adjust
the level of the sidetone audio as it is sent
to both the left and right headphone output
channels.
Mode 4 – Ch1L/Ch2R/Ch3LCh4R
Mode 4 is very similar to mode 1 except
instead of providing sidetone another
stereo pair can be routed to the left and
right headphone output channels. Dante
input channel 1 is routed to the left chan-
nel of the headphone output. Pot A adjusts
its level. Dante input channel 2 is routed
to the right headphone output channel and
pot B adjusts its level. A stereo pair can
enter the Model 204 by way of Dante input
channels 3 and 4. These signals, whose
level is adjusted using the pot C, are sent
to the left and right channels of the head-
phone output.
Mode 5 – Ch1LR/Ch2LR/Ch3LCh4R
Model 5 is a unique variation where two
monaural signals can be routed to both
the left and right headphone output chan-
nels while a stereo input source is routed
in stereo to the headphone output chan-
nels. Dante input channel 1 will be routed
to both the left and right channels of the
headphone output. Its level is controlled
by pot A. Dante input channel 2 will also
be routed to both the left and right chan-
nels of the headphone output. Its level will
be adjusted using pot B. A stereo pair can
enter the Model 204 by way of Dante input
channels 3 and 4. These signals will be
sent, in stereo, to the left and right chan-
nels of the headphone output. Their level
will be adjusted using pot C.

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ANNOUNCER’S CONSOLE
Headphone Gain Range
The overall level of the headphone output
can be configured as desired for specific
applications. The default setting, low, is de-
signed so that users with typical audio input
sources will be inclined to set the rotary
potentiometers at approximately 50% of
rotation. This would be appropriate for most
applications. The high setting would be ap-
plicable in cases where an extreme head-
phone output level is required or the audio
input sources are providing a level that is
lower than typical. Using the high setting in
the former application is not recommended
as hearing damage could result from expo-
sure to high signal levels.
Headphone Minimum Level
A setting in STcontroller is used to configure
the headphone output’s minimum level. In
the –40 dB setting the minimum headphone
output level is approximately 40 dB below
its maximum; the headphone output chan-
nels will never fully mute. This ensures
that any audio signal present on the uti-
lized Dante input channels will always be
present on the headphone output. In most
on-air broadcast applications this is the ap-
propriate setting, ensuring that a minimum
amount of signal is always present. When
full mute is selected moving a level potenti-
ometer to its fully counterclockwise position
will cause its associated headphone output
channel (or channels) to fully mute. If a
potentiometer is set to serve as a balance
control, moving it to either its fully coun-
terclockwise or fully clockwise position will
cause the associated signal to fully mute.
Selecting the full mute mode may be appro-
priate for applications where minimizing the
chance of audio “leakage” is important. This
could occur when during an event the con-
nected headset or headphones are at times
placed on a desk or tabletop.
Note that the action of pot C, when con-
figured to provide the sidetone function
(headphone modes 1, 2 or 3), will never be
impacted by the setting for the headphone
minimum level. Whenever pot C is control-
ling the sidetone level it will always cause
the signal to fully mute when it’s set to fully
counterclockwise.
Sidetone Mode
STcontroller allows the Model 204’s sidet-
one function to be configured as desired.
Sidetone is audio from the microphone
input that is sent to the headphone output
channels. This can be important, allowing
the user to “hear” themselves for perfor-
mance confirmation and comfort. Making
a specific selection from among the four
available modes will depend on the needs
of the application. If a “full mix” is being
provided to the Model 204’s Dante inputs
then locally-provided sidetone won’t be
needed and the off configuration should be
selected. The user will hear themselves by
way of audio signals being routed to the
Dante input channels. But if “mix-minus” au-
dio is being supplied to the Model 204 then
selecting a headphone source and routing
modes which enables sidetone (headphone
modes 1, 2, or 3) can be an important
means of establishing user confidence.
Then the sidetone mode configuration will
establish exactly when sidetone audio will
be sent to the headphone output channels.
Four sidetone modes are available:
• Off: In this mode the sidetone function is
not active.
• Main Button: In this mode the sidetone
function will be active whenever the
audio signal associated with the micro-
phone input is present on the Dante
main output channel and the microphone
output connector.

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MODEL 204
ANNOUNCER’S CONSOLE
• Latching: If this mode is selected the
main button’s function will alternate
between its active and inactive states
whenever the main button is pressed.
Upon power up the function will be in
its inactive state and the red LED associ-
ated with the button will be lit.
• Push to Talk/Tap to Latch: This mode is
a combination of the Push to Talk and
Latching modes. It’s similar to the way
talk pushbutton switches function on
user stations associated with broadcast
or production intercom systems. If the
main button is pressed and held the main
button’s function will be active. It will stay
active until the main button is released.
If the main button is momentarily
“tapped” the main button’s status will
change, either from inactive-to-active or
from active-to-inactive. Upon Model 204
power up the main button will be in its
inactive state and its red LED will be lit.
• Push to Mute/Tap to Latch: This mode is
a combination of the Push to Mute and
Latching modes. Whenever the main
button is momentarily “tapped” the main
button’s status will change, either from
active-to-inactive or inactive-to-active.
When the main button function is active
its green LED will be lit. The audio signal
associated with the microphone input
will be routed to both the Dante main
output channel and the microphone out-
put connector. Whenever the main but-
ton is pressed and held the audio signal
will mute on both the Dante main output
channel and the microphone output con-
nector and the button’s LED will change
from green to red. It will stay in this con-
dition until the main button is released.
Upon Model 204 power up the main
button will be in its inactive state and its
red LED will be lit.
• Talkback Button: In this mode the sidet-
one function will be active whenever the
talkback function is active and the audio
signal is present on the talkback Dante
output channel.
• Main and Talkback Buttons: In this
mode the sidetone function will be ac-
tive whenever the audio signal associ-
ated with the mic input is present on
the Dante main output channel and the
microphone output connector. The sidet-
one function will also be active whenever
the talkback function is active.
Button Operation – Main
STcontroller allows the configuration of the
main button to be selected. There are five
mode choices available:
• Push to Mute: If this mode is selected
the main button function will normally be
active and its green LED lit. The audio
signal associated with the microphone
input will be routed to both the Dante
main output channel and the micro-
phone output connector. Whenever the
main button is pressed the audio signal
will mute on both the Dante main out-
put channel and the microphone output
connector; the button’s LED will change
from green to red.
• Push to Talk: If this mode is selected
the main button function will normally
be inactive and the button’s red LED will
be lit. The audio signal associated with
the microphone input will not be routed
to the Dante main output channel and
the microphone output connector will
be muted. Whenever the main button
is pressed the audio signal will become
active on the Dante output channel and
the microphone output connector. In ad-
dition, the button’s green LED will light.

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ANNOUNCER’S CONSOLE
output’s function. There are three system
modes available. Understanding how each
specifically impacts Model 204 operation
will help to ensure that the desired opera-
tion is obtained and that maximum usability
will occur.
On-Air
When selected to the on-air mode, audio
on the Dante main output channel and the
microphone output connector will always
mute whenever the talkback function is
active. The on-air mode should be selected
for all on-air broadcast applications when
it’s imperative that the “on-air” audio sig-
nal be muted whenever on-air talent uses
the talkback function to communicate with
production personnel.
Production
When the system mode is set for produc-
tion, the audio signals on the Dante main
output channel and microphone output
connector are never muted in response to
talkback activity. The mic off/off function
operates independently of the talkback
function. This mode allows the Dante main
output channel to be used, for example, as
an additional talkback output. In this way
the Dante main output channel and the
talkback output channel can be used sepa-
rately and not impact each other. This also
allows both the main and talkback push-
buttons to be used simultaneously. When
selected for the correct application, the pro-
duction mode can prove to be very useful.
But it’s not appropriate for on-air use!
Production with Dim
This mode is identical to the production
mode with the exception that the head-
phone output reduces in level (“dims”)
whenever the main or talkback func-
tions are active. This mode was specifi-
cally provided to minimize the chance that
Button Operation – Talkback
The manner in which the talkback button
functions can be configured. There are
three mode choices available:
• Push to Talk: If this mode is selected the
talkback function will normally be inac-
tive and the LED associated with the
talkback button will not be lit. Whenever
the talkback button is pressed the talk-
back function will become active and its
green LED will light.
• Latching: If this mode is selected the
talkback function will alternate between
the active and inactive state whenever
the talkback button is pressed. Upon
power up the talkback function will be in
its inactive state and its button LED will
not be lit.
• Push to Talk/Tap to Latch: This mode is
a combination of the Push to Talk and
Latching modes. It’s similar to the way
talk pushbutton switches function on
user stations associated with broadcast
or production intercom systems. If the
talkback button is pressed and held the
talkback function will be active. It will
stay active until the talkback button is re-
leased. If the talkback button is momen-
tarily “tapped” the status of the talkback
function will change, either from inactive-
to-active or from active-to-inactive. Upon
Model 204 power up the talkback button
will be in its inactive state and its LED
will not be lit.
System Operating Mode
The system mode configures the overall
manner in which the Model 204 operates.
Specifically, it determines how the Dante
main output channel and the microphone
output connector operate vis-à-vis the
talkback function. The system mode can
also impact one facet of the headphone

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MODEL 204
ANNOUNCER’S CONSOLE
and headphones or earbud should have
been connected. Alternately, a broadcast-
style headset may have been connected.
If desired, a connection to the microphone
output should have been made. Some ap-
plications may utilize either or both of the
remote control inputs.
The Model 204 should have been placed
in the desired physical location. Using the
Studio Technologies STcontroller software
application the unit’s configuration should
have been selected to meet the needs of
the specific application. The Model 204’s
Dante configuration settings should have
been selected using the Dante Controller
software application. In this way the unit’s
two Dante audio output channels (Dante
transmitter channels) and four Dante audio
input channels (Dante receiver channels)
should have been routed, by way of Dante
“subscriptions,” to the receiver and trans-
mitter channels on associated Dante-
enabled equipment.
Initial Operation
The Model 204 will start to function as soon
as a Power-over-Ethernet (PoE) power
source is connected. However, it may take
20 to 30 seconds for full operation to com-
mence. Upon initial power up the three
status LEDs, located on the back panel
below the RJ45 jack, will begin to light as
network and Dante connections are estab-
lished. The COMP LED, adjacent to the
microphone input connector, may or may
not flash momentarily. The P48 LED, also
located adjacent to the microphone input
connector, will flash once to indicate that
it is functioning. The red and green LEDs
within the main and talkback pushbutton
switches will light in a short test sequence
to indicate that the application firmware
(embedded software) has started. Once
acoustical feedback will occur in applica-
tions where the headphone output is con-
nected to the inputs on amplified speakers
(or inputs on an amplifier associated with
loudspeakers). In this mode the level of the
headphone output channels is reduced by
18 dB whenever a main or talkback func-
tion is active. This mode is not appropriate
when headphones are going to be connect-
ed to the Model 204!
Remote Control Inputs
There are two remote control inputs. They
can be individually configured to mimic the
action of one of the pushbutton switches.
The choices are off, main button, or talk-
back button.
Button Backlight Intensity
The caps (top surfaces) of the two pushbut-
ton switches are able to be lit using internal
LEDs, one red and one green. When they
light and with what color depends on the
configuration of the Model 204 and the
current operating condition. The intensity
of these LEDs can be adjusted to meet the
needs of an application, specifically being
configured to perform optimally vis-à-vis
the amount of ambient light present in the
Model 204’s location. The choices are low
and high.
Operation
At this point all connections and configura-
tion steps should have been completed and
everything should be ready for Model 204
operation to commence. An Ethernet con-
nection with Power-over-Ethernet (PoE)
capability should have been made. Alter-
nately, a midspan power injector, in “se-
ries” with the Ethernet connection, should
have been put into place. A microphone

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ANNOUNCER’S CONSOLE
that it is ready to pass data with another
Dante device. The SYNC LED will light red
when the Model 204 is not synchronized
with a Dante network. It will light solid
green when the Model 204 is synchronized
with a Dante network and an external
clock source (timing reference) is being
received. It will slowly flash green when
this specific Model 204 is part of a Dante
network and is serving as the clock mas-
ter. It’s possible that up to 30 seconds may
be required for the SYNC LED to reach its
final state.
P48 Status LED
An LED indicator is located on the back
panel adjacent to the microphone input
connector. It is labeled P48 and will light
red whenever the P48 phantom power
source is active and providing power to the
microphone input.
Compressor Active LED and
Mic Preamp Gain
An LED indicator, orange in color, is locat-
ed on the back panel, also adjacent to the
microphone input connector. It is labeled
COMP and displays the status of the mi-
crophone audio compressor function. This
function controls the dynamic range of the
audio signal that can be present on the
Dante audio output (transmitter) channels
and sidetone audio sent to the headphone
output versus the signal present on the
microphone input. The compressor LED
will light whenever the input level from the
microphone, along with the configured
microphone preamplifier gain, is such that
the dynamic range of the signal is being
actively controlled. It’s perfectly acceptable
for this LED to light intermittently whenever
a user is talking at a normal voice level
into an associated microphone. But if the
that sequence has completed and the
Dante connection has been established
full operation will begin. The various LEDs
will then become operational, displaying
the status of their designated functions.
How to Identify a Specific
Model 204
Functions within the Dante Controller and
STcontroller software applications allow
a specific Model 204 unit to be identified.
Each application provides an “eyeball” icon
that when clicked will activate the Identify
function. When Identify is selected it will
send a command to a specific Model 204
unit. On that unit the LEDs associated with
the main and talkback pushbutton switch-
es will “flash” orange approximately eight
times (the actual on/off status of the but-
tons will not change). In addition, the SYS
and SYNC status LEDs, located directly
below the etherCON RJ45 connector on
the back panel, will slowly flash green.
After a few seconds the LED identification
pattern will cease and normal Model 204
button LED and Dante status LED opera-
tion will resume.
Ethernet and Dante Status
LEDs
Three status LEDs are located below the
etherCON RJ45 connector on the Model
204’s back panel. The LINK ACT LED will
light green whenever an active connection
to a 100 Mb/s Ethernet network has been
established. It will then flash in response to
all Ethernet data packet activity. The SYS
and SYNC LEDs display the operating sta-
tus of the Dante interface and its associat-
ed network activity. The SYS LED will light
red upon Model 204 power up to indicate
that the Dante interface is not ready. After
a short interval it will light green to indicate