Studio Technologies 204 User manual

Copyright © 2020 by Studio Technologies, Inc., all rights reserved
www.studio-tech.com
User Guide
Issue 3, August 2020
This User Guide is applicable for serial numbers
M204-00501 and later with application firmware 1.4 and later
and STcontroller application version 2.04.00 and later.
50639-0820, Issue 3
Model 204 Announcer’s Console

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Model 204 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 3
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 3, August 2020 Model 204 User Guide
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MODEL 204
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Revision History
Issue 3, August 2020:
• Documents addition of Main Out Tally function. (Applies only to serial numbers
M204-00501 and later.)
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 3, August 2020
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MODEL 204
ANNOUNCER’S CONSOLE
Introduction
The Model 204 Announcer’s Console offers
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 technol-
ogy with AES67 compatibility 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 posi-
tion 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 supported. Two
remote control inputs allow external switches
or contact closures to activate the main and
talkback button functions. One of the inputs
can also be configured to provide a low-
voltage DC “tally” output that follows the
state of the main output.
Model 204 operating features are configured
using the STcontroller software application.
An extensive set of parameters allows the
unit’s functions to be tailored to meet the
needs of many applications. STcontroller 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 facili-
ties. 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 function
Figure 1. Model 204 Announcer’s Console front
and rear views

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can provide the user with a microphone
confidence signal. Two Dante audio output
channels, one designated as main and the
other as talkback, are routed via an associ-
ated 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 performed 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 envi-
ronments easy to accomplish. The talkback
audio channel is available as a Dante out-
put channel which makes routing to an input
on a variety of devices, such as matrix inter-
com systems, audio consoles, and monitor
loudspeaker systems, simple and flexible.
Some applications may benefit from not
utilizing the Model 204’s Dante main output
channel. This typically won’t be an issue
of inadequate audio quality but rather a
need to match work-flow requirements. For
example, for lip-sync or transmission pur-
poses it may be optimal to have the on-air
audio transported as an embedded signal
along with the associated camera video. Al-
ternately, all on-air audio sources may need
to connect to inputs on an audio console or
console-related I/O unit. Supporting these
scenarios is not a problem as the Model
204 supplies a microphone output connec-
tion that’s specifically intended for this pur-
pose. 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 sim-
ple, essentially a passive path that routes
a signal connected to the microphone 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 con-
nector 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 associated with a
PoE-enabled network switch. This connec-
tion provides both power and bidirectional
digital audio. A broadcast headset or hand-
held (“stick”) microphone can be directly
connected to the unit’s 3-pin XLR mic input
connector. The input is compatible with dy-
namic or condenser microphones. The inte-
grated P48 phantom power source provides
support for a wide range of condenser mi-
crophones. A 3-pin XLR microphone output
connector provides a “direct mic out” func-
tion 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 activation of the
main and talkback button functions. A low-
voltage/low-current DC output can also be
implemented providing a Main Out Tally
function. The STcontroller software applica-
tion is used to configure the wide range of

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MODEL 204
ANNOUNCER’S CONSOLE
Model 204 operating parameters. This al-
lows the unit’s performance to be optimized
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 net-
work (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 connec-
tor. 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 efficient inter-
connection with the associated data net-
work. To support PoE power management,
the Model 204’s PoE interface enumerates
(reports) to the power sourcing 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) chan-
nels and four Dante receiver (audio input)
channels can be assigned (routed or “sub-
scribed”) to other devices using the Dante
Controller software application. The Dante
transmitter and receiver channels are lim-
ited 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 status.
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 dy-
namic-range microphone preamplifier and
associated voltage-controlled-amplifier
(VCA) dynamics controller (compressor)
ensures that mic input audio quality 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.
This provides flexibility, allows precise

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ANNOUNCER’S CONSOLE
control, and keeps the three level potentiom-
eters 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 circuitry. High signal
levels can be provided to a variety of head-
sets, 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. There are no mechanical switch
settings or button-press sequences required
to configure how the unit functions. Select-
able parameters include microphone pre-
amplifier gain, P48 phantom power on/off,
button operation, remote control inputs
(included tally output), headphone output
mode, sidetone operation, and overall unit
operation. The gain of the microphone pre-
amplifier can be selected from among four
choices. This allows the Model 204 to match
the output 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 condenser
(capacitor) microphones.
The main and talkback pushbutton switches
can be individually configured. The main but-
ton 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 tai-
lored to meet the specific 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 momentari-
ly 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 control
inputs. Configuration choices allow these
to be assigned to work in parallel 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. Remote Control Input 1
can also be configured to provide a Main Out
Tally function.
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 monitoring
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 chan-
nels. 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 talent cueing
audio (“IFB”) need to be independently
sent to the left and right headphone out-
put channels. It would be common for
program audio with director interrupt to
enter the Model 204 by way of Dante
input (receiver) channel 1 and be sent to
the left headphone output. Program-only

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ANNOUNCER’S CONSOLE
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 sidetone 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 func-
tion.
• 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 levels of
the signals as they are sent to the left
and right headphone output channels. 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 sig-
nals as they are sent to the headphone
output channels. Pot C is used to control
the level of a stereo input signal as it is
routed to the left and right channels of the
headphone output. This stereo 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 pre-
amplifier to be returned to the headphone
output. This is important as different appli-
cations 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 dis-
abled. In the case where a mix-minus signal
is present, providing the user with sidetone
at the appropriate time(s) can be an impor-
tant means of confirming the signal that’s
coming from the connected microphone.
The headphone gain range configuration
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.
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 pro-
duction audio channels. Other applications
will benefit from the two available produc-
tion modes.

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Future Capabilities and
Firmware Updating
The Model 204 was designed so that its ca-
pabilities 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 in-
terface. 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 available 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 using a cable-
mounted 3-pin male XLR connector. A set of
headphones or an earpiece will be connect-
ed by way of a ¼-inch plug. If desired, the
Model 204’s microphone-level output may be
interfaced with other equipment using a ca-
ble 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. Remote Control Input 1 can be config-
ured such that it provides a tally output.
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 Ethernet
switch power management, enumerating
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 connec-
tion 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
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.