Studio Technologies 205 User manual

Copyright © 2021 by Studio Technologies, Inc., all rights reserved
studio-tech.com
User Guide
Issue 4, March 2021
This User Guide is applicable for serial numbers
M205-00501 and later with application firmware 1.5 and later.
50641-0321, Issue 4
Model 205 Announcer’s Console

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Model 205 User Guide Issue 4, March 2021
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MODEL 205
ANNOUNCER’S CONSOLE
Table of Contents
Revision History ...................................................................................... 4
Introduction .............................................................................................. 5
Getting Started ........................................................................................ 10
Operation ................................................................................................. 20
Technical Notes ....................................................................................... 25
Specifications .......................................................................................... 29
Appendix A: Model 205 Block Diagram ................................................... 30
Appendix B: STcontroller Default Model 205 Configuration Values ......... 31

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Revision History
Issue 4, March 2021:
1. Documents revisions and additions to Button Backlight modes.
Issue 3, August 2020:
1. Documents addition of Main Out Tally function. (Applies only to serial numbers
M205-00501 and later.)
Issue 2, October 2018:
1. Documents addition of the Push to Mute/Tap to Latch main button operating mode.
Issue 1, May 2018:
1. Initial release.

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Introduction
The Model 205 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 205 “cute” or “cool” would be accurate;
its nicely proportioned but diminutive size
makes it ideal for use in space-constrained
locations. The Model 205 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 205’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 205 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
205’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 205 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 205 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 (input) audio
channels supply the user with their talent
cue (IFB) signals. Should the cue signal
be “mix-minus” an integrated sidetone
Figure 1. Model 205 Announcer’s Console front
and rear views

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function can provide the user with a mi-
crophone confidence signal. Three Dante
transmitter (output) audio channels, one
designated as main and two as talkback,
are routed via an associated local-area net-
work (LAN) to inputs on Dante-compatible
devices. Three pushbutton switches, main
and two 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 205 makes
integration into a wide range of on-air en-
vironments easy to accomplish. And with
two talkback audio channels available as
Dante transmitter (output) channels routing
to inputs on a variety of devices, such as
matrix intercom systems, audio consoles,
and monitor loudspeaker systems, is simple
and flexible.
Some applications may benefit from not
utilizing the Model 205’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
205 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
205’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 mi-
crophone 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 205 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 con-
nection provides both power and bidirec-
tional 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 phantom power source
provides support for a wide range of con-
denser microphones. A 3-pin XLR micro-
phone output connector provides a “direct
mic out” function for integration with micro-
phone 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 205’s remote
control inputs to allow activation of the
main and talkback button functions. A low-
voltage/low-current DC output can also

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be implemented providing a Main Out
Tally function. The STcontroller software
application is used to configure the wide
range of Model 205 operating parameters.
This allows the unit’s performance to be
optimized to meet the needs of specific
applications.
The user is presented with three 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 205 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 205’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 205’s PoE interface enumerates
(reports) to the power sourcing equipment
(PSE) that it’s a class 2 (low power) device.
Dante Audio-over-Ethernet
Audio data is sent to and received from
the Model 205 using the Dante audio-over-
Ethernet media networking technology. As
a Dante-compliant device, the Model 205’s
three Dante transmitter (output) channels
and four Dante receiver (input) channels
can be assigned (routed or “subscribed”)
to other devices using the Dante Controller
software application. The Dante transmit-
ter (output) and receiver (input) 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 status.
An additional LED displays the status of the
associated Ethernet connection.
The Model 205 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 205’s audio performance is
completely “pro.” A low-noise, wide dynamic-
range microphone preamplifier and asso-
ciated voltage-controlled-amplifier (VCA)
dynamics controller (compressor) ensures
that mic input audio quality is preserved
while minimizing the chance of signal over-
load. The output of the microphone preamp
and compressor is routed to an analog-to-
digital conversion (ADC) section that sup-
ports 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 signals arrive via the four Dante
receiver (input) channels and pass into the
Model 205’s microprocessor. The supported
sampling 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 control,
and keeps the three level potentiometers

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from having to directly handle analog audio
signals. The audio channels destined for
the phones outputs are sent to a high-per-
formance 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 205 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
(including tally output), 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 205 to
match the output sensitivity of a range of
handheld and headset-associated micro-
phones. 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
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 205’s operation
to be tailored 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 momentarily disable it. The
talkback buttons would most likely be set to
the push to talk mode as its use would be
intermittent.
Red and green LEDs are associated with
the main and talkback pushbutton switches.
A configuration choice allows selection of
the manner in which the LEDs will light
under various operating conditions. This
capability was specifically provided to as-
sist users who have trouble observing the
differences between colors, typically issues
with red and green. “Color blindness” is not
infrequently found in men and can make
effective use of some electronic equipment
difficult. In addition, the Model 205’s abil-
ity to control the colors presented by the
pushbuttons can be useful for international
applications. Local preferences will often
determine which color is associated with a
function being “on” and which color is as-
sociated with a function being “off.”
The Model 205 provides two remote control
inputs. Configuration choices allow each
input to be assigned to work in parallel with
the main or one of the 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 broad-
cast, or as a production support tool, the
Model 205 should be able to achieve the
desired configuration.

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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
interrupt to enter the Model 205 by way
of Dante receiver (input) channel 1 and
be sent to the left headphone output.
Program-only audio, entering the unit by
way of Dante receiver (input) channel 2,
would be sent to the right headphone out-
put. 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
205 by way of Dante receiver (input)
channels 1 and 2 and is routed to the left
and right channels of the headphone out-
put. In this mode pot A controls the overall
level of this stereo signal and pot B con-
trols 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 receiver
(input) channels 1 and 2 while pot B ad-
justs the level of the stereo pair entering
on Dante receiver (input) channels 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 205 by way
of Dante receiver (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 chan-
nels. A stereo input signal, entering the
unit by way of Dante receiver (input) chan-
nels 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 re-
ceiver (input) channels 1 and 2 are used
to bring these audio signals into the Model
205. Pots A and B are used to control the
level of the signals 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 receiver
(input) channels 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 applica-
tions may provide a “full mix” or a “mix-
minus” talent cue signal. If a full mix cue
signal is provided then sidetone audio will

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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 205 users. The appropriate setting will
depend on the specific audio sources pro-
vided to the unit as well as user preference.
Three system modes select the overall way
in which the Model 205 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 produc-
tion audio channels. Other applications will
benefit from the two available production
modes.
Future Capabilities and
Firmware Updating
The Model 205 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 205 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
205 Announcer’s Console and instructions
on how to obtain an electronic copy of
this guide. As a device that is Power-over-
Ethernet (PoE) powered, no external power
source is provided.
Connections
In this section signal interconnections will
be made using the five connectors located
on the back of the Model 205’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 mi-
crophone will be connected using a cable-
mounted 3-pin male XLR connector. A set
of headphones or an earpiece will be con-
nected by way of a ¼-inch plug. If desired,
the Model 205’s microphone-level output
may be interfaced with other equipment us-
ing 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-conductor
3.5 mm jack. Remote Control Input 1 can
be configured 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 205 operation. This one
connection will provide both the Ethernet
data interface and power for the Model
205’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 op-
eration. The Model 205 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 205’s enclosure. This allows

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connection by way of a cable-mounted ether-
CON connector or a standard RJ45 plug.
The Model 205’s Ethernet interface supports
auto MDI/MDI-X so that a “cross-over” or
“reversing” cable will never be required.
Microphone Input
The Model 205 provides a 3-pin female XLR
connector that allows a balanced dynamic or
phantom powered condenser powered mi-
crophone to be connected. The microphone
can be a standalone handheld (“stick”) type
or can be part of a broadcast-style head-
set. The Model 205’s microphone input is
directly compatible with balanced dynamic
or P48 phantom powered microphones. 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 configuration setting in
STcontroller allows the P48 phantom power
source to be enabled or disabled as desired.
Details on configuration settings will be de-
scribed later in this guide.
While the Model 205 provides an excellent
source of P48 phantom power, it’s pos-
sible that an input on an associated piece of
equipment is already providing microphone
power. This could be connected to the Model
205 by way of the microphone output con-
nector. This would not create a problem
since the circuitry that connects audio from
the Model 205’s microphone output con-
nector to the Model 205’s microphone input
connector will pass this microphone power
through without interruption. This situation
could be relevant when the Model 205’s
microphone output connector is interfaced
with the microphone input on a broadcast
camera, audio console, microphone mixer, or
similar equipment. Inputs on these devices
would typically offer phantom power which in
some cases may have been enabled.
Headphone Output
The Model 205 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 convention
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 205’s
headphone jack the Model 205’s right head-
phone output channel 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 head-
phone output channel. Refer to the Configu-
ration section later in this guide for details
on setting the headphone audio routing to
best accomplish this condition.
Microphone Output
A 3-pin male XLR connector provides a
microphone-level output that’s directly
related to the microphone input. Technically
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 205’s
Dante main output channel is active the
microphone signal will also pass through to

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the Model 205’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 205’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 205’s
microphone input connector to the Model
205’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 micro-
phone signal but shouldn’t impact any real-
world applications.
Remote Control Inputs
Provision has been made to allow exter-
nal switches or contact closures to mimic
operation of the main and talkback pushbut-
ton switches. The exact functioning of the
two remote control inputs is determined by
configuration settings, details of which are
discussed later in this guide. A 3-conductor
3.5 mm jack is located on the Model 205’s
back panel and provides access to the two
remote control inputs. The input circuitry is
“active low,” with 3.4 k ohm resistors con-
nected to +3.3 volts DC to act as input “pull
ups.” (In addition, a combination of resis-
tors and capacitors provide ESD protection,
minimizing the chance of damage due to
static discharge or other extraneous sig-
nals.) A current flow of less than one mil-
liampere is required for a remote control
input to be recognized as active.
Remote Control Input 1 can also be config-
ured to provide a Main Tally Output func-
tion. This will provide a 3.3 volts DC, 23
milliampere maximum output whenever the
main output function is active. The tally out-
put can directly drive an LED or be utilized
by the input on another piece of equipment.
Prepare the interconnecting cable and as-
sociated 3-conductor (TRS) 3.5 mm 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. Refer to Figure 2
for connection details.
Figure 2. 3-conductor (TRS) 3.5 mm plug
configured for use with remote control inputs

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Dante Configuration
For audio to pass to and from the Model 205
requires that several Dante-related param-
eters be configured. These configuration
settings will be stored in non-volatile memory
within the Model 205’s circuitry. Configuration
will typically be done with the Dante Control-
ler software application which is available for
download free of charge at audinate.com.
Versions of Dante Controller are available
to support Windows and OS X® operating
systems. The Model 205 uses the Ultimo
integrated circuit to implement the Dante
functionality. The Model 205 can also be
configured to meet the requirements of the
AES67 standard. This requires a setting to
be enabled within the Device Info section of
the Dante Controller application.
The three Dante transmitter (output) chan-
nels associated with the Model 205’s Dante
interface must be assigned to the desired
receiver (input) channels on associated
equipment. This achieves routing of the
Model 205’s three audio output channels to
the device (or devices) that will be “listening”
to them. Within Dante Controller a “subscrip-
tion” is the term used for routing a transmitter
flow (a group of up to four output channels)
to a receiver flow (a group of up to four input
channels). The number of transmitter flows
associated with an Ultimo integrated circuit
is limited to two. These can either be uni-
cast, multicast, or a combination of the two.
If the Model 205’s Dante transmitter (output)
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 5422A Dante
Intercom Audio Engine, can be used to
“repeat” the signals.
The desired audio sources need to be routed
to the Dante receiver (input) channels as-
sociated with the Model 205. The unit pro-
vides four audio input channels. The number
utilized will depend on the specific applica-
tion. Following the unit’s headphone source
and routing configuration selection these
audio signals will be sent to the Model 205’s
2-channel headphone output.
The Model 205 supports audio sample rates
of 44.1 and 48 kHz with no pull-up/pull-down
values available. In most cases it’s antici-
pated that the default rate of 48 KHz will be
appropriate. While technically the Model 205
can serve as a Leader clock for a Dante net-
work (as can all Dante-enabled devices) in
virtually all cases the unit will be configured
to receive “sync” from another device.
The Model 205 has a default Dante device
name of ST-M205 along with a unique suffix.
The suffix identifies the specific Model 205
that is being configured. The suffix’s actual
alpha and/or numeric characters relate to
the MAC address of the unit’s Ultimo inte-
grated circuit. The three Dante transmitter
(output) channels have default names of
Main, Talkback 1, and Talkback 2. The four
Dante receiver (input) channels have default
names of Headphone Ch1, Headphone
Ch2, Headphone Ch3, and Headphone
Ch4. Using Dante Controller the default
device name and channel names can be
revised as appropriate for the specific
application.
Model 205 Configuration
The STcontroller software application is used
to configure the way in which the Model 205
functions. No DIP switch settings or other
local actions are used to configure the unit.
This makes it imperative that STcontroller
be available for convenient use in a personal
computer that’s connected to the related
LAN.

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Installing STcontroller
STcontroller is available free of charge on
the Studio Technologies’ website. If re-
quired, 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 205 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 205 units to be configured will ap-
pear in the device list. Use the Identify com-
mand to allow easy recognition of a specific
Model 205 unit. Double-clicking on a device
name will cause the associated configura-
tion menu to appear. Review the current
configuration and make any changes that
are desired.
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
• Main and talkback button operating
modes
• System operating mode
• Remote control inputs
• Button backlight modes
Changes made using STcontroller will be
immediately reflected in the unit’s operation;
no Model 205 “reboot” is required. Each
time a change is made the main and talk-
back buttons on the front panel will momen-
tarily flash orange in a distinctive pattern to
indicate that a command from STcontroller
has been received.
P48 Phantom Power
STcontroller allows selection of the on/off
status of the microphone input’s P48 phan-
tom power source. The on/off status is
displayed by way of an LED, red in color,
located on the back panel adjacent to the
microphone input connector. Select the sta-
tus 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 connec-
tion made to the microphone output con-
nector. In this case simply turn off the Model
205’s P48 phantom power source. The
external source of microphone power will
“pass thru” from the microphone output con-
nector to the microphone input connector.
Microphone Input Gain
The gain of the Model 205’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 205’s
enclosure adjacent to the microphone input
connector, can act as a guide when setting
the preamp gain. When a voice signal at a
normal level is present on the microphone
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 normal
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 appropriate.
But unless otherwise indicated, 43 dB is
typically a good initial choice.

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Headphone Audio Sources and Routing
STcontroller allows selection from among five
headphone audio source and routing modes.
Each mode is distinct and careful selection
will help optimize the Model 205’s operation
for a range of applications.
• 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
headphone output channels. Dante re-
ceiver (input) channel 1 will be routed to
the left headphone output channel and pot
A will adjust its level. Dante receiver (input)
channel 2 will be routed to the right head-
phone 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/
SidetoneLR: 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 broad-
cast. In these applications it’s typical to
want the user to have a single potentiom-
eter to simultaneously adjust the level of
a stereo pair while a separate potentiom-
eter is used to adjust the left/right level
balance.
When set for mode 2 Dante receiver
(input) channel 1 will be routed to the
left headphone output channel and Dante
receiver (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/
SidetoneLR: Mode 3 can be useful in ap-
plications where two stereo signals need
to be provided to the user on the left and
right headphone output channels. In this
mode Dante receiver (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
receiver (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
receiver (input) channel 1 is routed to the
left channel of the headphone output. Pot
A adjusts its level. Dante receiver (input)
channel 2 is routed to the right head-
phone output channel and pot B adjusts
its level. A stereo pair can enter the Model
205 by way of Dante receiver (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 receiver (input) channel 1 will
be routed to both the left and right chan-
nels of the headphone output. Its level is
controlled by pot A. Dante receiver (input)

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ANNOUNCER’S CONSOLE
channel 2 will also be routed to both the
left and right channels of the headphone
output. Its level will be adjusted using pot
B. A stereo pair can enter the Model 205
by way of Dante receiver (input) chan-
nels 3 and 4. These signals will be sent,
in stereo, to the left and right channels of
the headphone output. Their level will be
adjusted using pot C.
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 utilized
Dante receiver (input) channels will always
be present on the headphone output. In
most on-air broadcast applications this is
the appropriate setting, ensuring that a
minimum amount of signal is always pres-
ent. When full mute is selected moving a
level potentiometer to its fully counterclock-
wise position will cause its associated head-
phone output channel (or channels) to fully
mute. If a potentiometer is set to serve as a
balance control, moving it to either its fully
counterclockwise 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 205’s sidetone
function to be configured as desired. Side-
tone 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 performance confirma-
tion 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
205’s Dante receiver (input) channels 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
receiver (input) channels. But if “mix-minus”
audio is being supplied to the Model 205
then selecting a headphone source and rout-
ing modes which enables sidetone (head-
phone modes 1, 2, or 3) can be an important
means of establishing user confidence. Then
the sidetone mode configuration will estab-
lish exactly when sidetone audio will be sent
to the headphone output channels.

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ANNOUNCER’S CONSOLE
the Dante main output channel and the
microphone output connector. Whenever
the main button is pressed the audio signal
will become active on both the Dante main
output channel and the microphone output
connector.
• 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.
• 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 sta-
tions associated with broadcast or produc-
tion intercom systems. If the main button is
pressed and held the main button’s func-
tion 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 in-
active-to-active or from active-to-inactive.
Upon Model 205 power up the main button
function will be in its inactive state.
• 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. The
audio signal associated with the micro-
phone input will be routed to both the
Dante main output channel and the micro-
phone output connector. Whenever the
main button is pressed and held the audio
signal will mute on both the Dante main
output channel and the microphone output
connector. It will stay in this condition until
the main button is released. Upon Model
205 power up the main button function
will be in its inactive state.
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 microphone
input is present on the Dante main output
channel and the microphone output
connector.
• Talkback Button: In this mode the sidetone
function will be active whenever either or
both of the talkback functions are active
and the audio signal is present on the
talkback 1 or talkback 2 Dante transmitter
(output) channels.
• Main and Talkback Buttons: In this mode
the sidetone function will be active when-
ever the audio signal associated with the
mic input is present on the Dante main
output channel and the microphone output
connector. The sidetone function will also
be active whenever either or both of the
talkback functions are 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 ac-
tive. 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 output chan-
nel and the microphone output connector.
• Push to Talk: If this mode is selected the
main button function will normally be inac-
tive. The audio signal associated with the
microphone input will be muted on both

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ANNOUNCER’S CONSOLE
output connector operate vis-à-vis the
talkback functions. The system mode can
also impact one facet of the headphone
output’s function. There are three system
modes available. Understanding how each
specifically impacts Model 205 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 con-
nector will always mute whenever the
talkback 1 or talkback 2 functions are ac-
tive. 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
a talkback function to communicate with
production personnel.
• Production: When the system mode is
set for Production, the audio signals
on the Dante main output channel and
microphone output connector are never
muted in response to talkback function
activity. The mic off/off function operates
independently of the talkback functions.
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
two talkback output channels can be
used separately and not impact each
other. This also allows both the main and
talkback pushbuttons to be used simul-
taneously. When selected for the correct
application, the production mode can
prove to be very useful. But it’s not appro-
priate for on-air use!
• Production with Dim: This mode is iden-
tical to the production mode with the
exception that the headphone output
Button Operation – Talkback
The manner in which the two talkback but-
tons function can be configured. One con-
figuration setting applies to both talkback
buttons. There are three mode choices
available:
• Push to Talk: If this mode is selected the
talkback functions will normally be inac-
tive and the LED associated with each
talkback button will not be lit. Whenever a
talkback button is pressed its associated
talkback function will become active and
depending on the unit’s configuration, the
button’s green or red LED will light.
• Latching: If this mode is selected the
talkback functions will alternate between
their active and inactive states whenever
a talkback button is pressed. Upon power
up the talkback functions will be in their
inactive state and their button LEDs 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 pro-
duction intercom systems. If a talkback
button is pressed and held its talkback
function will be active. It will stay active
until the talkback button is released. If a
talkback button is momentarily “tapped”
the status of the talkback function will
change, either from inactive-to-active or
from active-to-inactive. Upon Model 205
power up the talkback buttons will be in
their inactive state and their LEDs will
not be lit.
System Operating Mode
The system mode configures the overall
manner in which the Model 205 operates.
Specifically, it determines how the Dante
main output channel and the microphone

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ANNOUNCER’S CONSOLE
The word High in a choice’s title means
that the intensity of both the red and green
LEDs are at the Model 205’s maximum. The
word Low in a choice’s title means that the
intensity is at a reduced level. The amount
of ambient light present at the Model 205’s
location will typically be the determining fac-
tor when selecting the LED intensity.
Off When Inactive relates to the action of
the LEDs when the main output function
is not active (off). Traditionally, an LED is
lit in the pushbutton switch to indicate that
the function is in its inactive, off, standby, or
ready-to-use state. To assist users who
have trouble with color discrimination
(“color blindness”) the main pushbutton
can be configured to not be lit when the
function is not active (off). In this case only
when the function is active (on) will an LED
light in the pushbutton switch.
• Standard – High: In this mode the opera-
tion of the LEDs in the main and talkback
buttons will match the way in which Stu-
dio Technologies has implemented this
for many years. When the main output
function is in its inactive (off) state the
main button’s red LED will be lit. When
the main output function is in its active
(on) state the main button’s green LED
will light. When a talkback function is in
its inactive (off) state neither of its button
LEDs will be lit. When a talkback func-
tion is in its active (on) state its talkback
button’s green LED will light. The intensity
of the LEDs will be at their maximum.
• Standard – Low: The operation is the
same as Standard – High except the
intensity of the LEDs will be significantly
lower.
• Standard – High – Off When Inactive:
This mode is offered to assist users who
have a reduced ability to discriminate
reduces in level (“dims”) whenever the
main, talkback 1, or talkback 2 functions
are active. This mode was specifically
provided to minimize the chance that
acoustical feedback will occur in ap-
plications where the headphone output
is connected to the inputs on amplified
speakers (or inputs on an amplifier as-
sociated with loudspeakers). In this mode
the level of the headphone output chan-
nels is reduced by 18 dB whenever a
main or talkback function is active. This
mode is not appropriate when head-
phones are going to be connected to the
Model 205!
Remote Control Inputs
There are two remote control inputs which
can be individually configured. Remote
Control Input 1 can be configured to be dis-
abled (off), to mimic the action of either the
main or talkback pushbutton switches, or to
provide a main output tally function. Remote
Control Input 2 can be configured to be dis-
abled (off), or mimic the action of either the
main or talkback pushbutton switches.
Button Backlight Mode
Choices include Standard – High, Standard
– Low, Standard – High – Off When Inac-
tive, Reverse – High, Reverse – Low, and
Reverse – High – Off When Inactive.
The Model 205’s three pushbutton switches
contain red and green LEDs that are used
to provide an indication of a function’s
status. The word Standard in a choice’s title
means that red is utilized to indicate that
a function is not active (off) and green is
utilized to indicate that a function is active
(on). The word Reverse in a title means that
green is utilized to indicate when a function
is not active (off) and red when a function is
active (on).

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Operation
At this point all connections and configura-
tion steps should have been completed
and everything should be ready for Model
205 operation to commence. An Ether-
net connection with Power-over-Ethernet
(PoE) capability should have been made.
A microphone 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 applications may utilize either or both
of the remote control inputs. Remote Con-
trol Input 1 can provide a low-voltage DC
tally output that is active whenever the main
output function is active. It may be used to
light a status LED or trigger the input on
another piece of equipment.
The Model 205 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 205’s
Dante configuration settings should have
been selected using the Dante Controller
software application. In this way, the unit’s
three Dante transmitter (output) channels
and four Dante receiver (input) channels
should have been routed, by way of Dante
“subscriptions,” to the receiver and transmit-
ter channels on associated Dante-enabled
equipment.
Initial Operation
The Model 205 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 sta-
tus LEDs, located on the back panel below
between the colors red and green. In this
mode when the main output function is in
its inactive (off) state neither of the main
button’s LEDs will be lit. When the main
output function is in its active (on) state the
main button’s green LED will light. When a
talkback function is in its inactive (off) state
neither of its talkback button’s LEDs will be
lit. When a talkback function is in its active
(on) state the talkback button’s green LED
will light. The intensity of the LEDs will be
at their maximum.
• Reverse – High: In this mode when the
main output function is in its inactive (off)
state the main button’s green LED will be
lit. When the main output function is in its
active (on) state the main button’s red LED
will light. When a talkback function is in
its inactive (off) state neither of its button
LEDs will be lit. When a talkback func-
tion is in its active (on) state the talkback
button’s red LED will light. The intensity of
the LEDs will be at their maximum.
• Reverse – Low: The operation is the same
as Reverse – High except the intensity of
the LEDs will be significantly lower.
• Reverse – High – Off When Inactive: This
mode is also intended to offer “color blind”
users an enhanced ability to determine
the state of the main output function.
When the main output function is in its
inactive (off) state neither of the main
button’s LEDs will be lit. When the main
output function is in its active (on) state
the main button’s red LED will light. When
a talkback function is in its inactive (off)
state neither of its button LEDs will be lit.
When a talkback function is in its active
(on) state its button’s red LED will light.
The intensity of the LEDs will be at their
maximum.