Studio Technologies 205 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
M205-00501 and later with application firmware 1.4 and later
and STcontroller application version 2.04.00 and later.
50641-0820, Issue 3
Model 205 Announcer’s Console

This page intentionally left blank.

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 3
MODEL 205
ANNOUNCER’S CONSOLE
Table of Contents
Revision History ........................................................... 4
Introduction ................................................................... 5
Getting Started ............................................................. 10
Operation ...................................................................... 19
Technical Notes ............................................................ 24
Specifications ............................................................... 28
Appendix A: Model 205 Block Diagram ........................ 29

Issue 3, August 2020 Model 205 User Guide
Page 4 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
Revision History
Issue 3, August 2020:
• Documents addition of Main Out Tally function. (Applies only to serial numbers
M205-00501 and later.)
Issue 2, October 2018:
• Documents addition of the Push to Mute/Tap to Latch main button operating mode.
Issue 1, April 2018:
• Initial release.

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 5
MODEL 205
ANNOUNCER’S CONSOLE
Introduction
The Model 205 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 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 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 205’s audio quality is excellent, with
low distortion, low noise, and ample head-
room. 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
position 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 support-
ed. 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 config-
ured using the STcontroller personal com-
puter software application. An extensive set
of parameters allows the unit’s functions to
be tailored to meet the needs of many ap-
plications. 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 (audio input)
channels supply the user with their talent
cue (IFB) signals. Should the cue signal
Figure 1. Model 205 Announcer’s Console front
and rear views

Issue 3, August 2020 Model 205 User Guide
Page 6 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
be “mix-minus” an integrated sidetone func-
tion can provide the user with a microphone
confidence signal. Three Dante audio out-
put channels, one designated as main and
two as talkback, are routed via an associ-
ated local-area network (LAN) to inputs on
Dante-compatible devices. Three pushbutton
switches, main and two talkback, provide
the user with direct control over audio rout-
ing. 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 micro-
phone level, the Model 205 makes integra-
tion into a wide range of on-air environments
easy to accomplish. And with the two talk-
back audio channels available as Dante out-
put 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 purposes it may
be optimal to have the on-air audio trans-
ported 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-re-
lated I/O unit. Supporting these scenarios is
not a problem as the Model 205 supplies a
microphone output connection that’s specifi-
cally intended for this purpose. Simply con-
nect 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, es-
sentially a passive path that routes a signal
connected to the microphone input connec-
tor directly to the microphone output con-
nector. 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 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 be
implemented providing a Main Out Tally
function. The STcontroller software applica-
tion is used to configure the wide range of

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 7
MODEL 205
ANNOUNCER’S CONSOLE
Model 205 operating parameters. This al-
lows 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-re-
liability 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.
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 205 using the Dante audio-over-
Ethernet media networking technology. As
a Dante-compliant device, the Model 205’s
three 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 205 is compatible with the
AES67 interoperability standard. In this
mode the three transmitter (output) chan-
nels will function in multicast; unicast is not
supported. In addition, the unit is compat-
ible with the Dante Domain Manager™
(DDM) software application.
Audio Quality
The Model 205’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
205’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 con-

Issue 3, August 2020 Model 205 User Guide
Page 8 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
trol, 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 205 can be configured to meet
the needs of specific applications and user
preferences. All configuration choices are
performed using the STcontroller personal
computer software application. There are
no mechanical switch settings or button-
press sequences required to configure how
the unit functions. Selectable parameters
include microphone preamplifier gain, P48
phantom power on/off, button operation,
remote control inputs (included tally output),
headphone output mode, sidetone opera-
tion, and overall unit operation. The gain of
the microphone preamplifier can be se-
lected from among four choices. This allows
the Model 205 to match the output sensitiv-
ity of a range of handheld and headset-as-
sociated 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
button can be selected to operate from
among five modes while the talkback but-
tons can be selected from among three.
These choices allow the Model 205’s op-
eration to be tailored to meet the specific
needs of many applications. As an example,
for on-air sports applications the main but-
ton would typically be configured to provide
a push to mute (cough) function. The mi-
crophone signal on the Dante main output
channel and the microphone output con-
nector would remain active unless the talent
needs to momentarily disable it. The talkback
buttons would most likely be set to their push
to talk modes as their use would be intermit-
tent.
The Model 205 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 situa-
tion to be implemented. Whether for use in
on-air sports, an awards show broadcast, or
as a production support tool, the Model 205
should be able to achieve the desired con-
figuration.
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 output
channels. It would be common for program
audio with director interrupt to enter the
Model 205 by way of Dante input (receiver)

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 9
MODEL 205
ANNOUNCER’S CONSOLE
channel 1 and be sent to the left head-
phone output. Program-only audio, enter-
ing 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 side-tone function where micro-
phone 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 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 head-
phone 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 205 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 205. 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 205 users. The appropriate setting
will depend on the specific audio sources
provided to the unit as well as user prefer-
ence.
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 pro-
duction audio channels. Other applications
will benefit from the two available produc-
tion modes.

Issue 3, August 2020 Model 205 User Guide
Page 10 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
Future Capabilities and
Firmware Updating
The Model 205 was designed so that its
capabilities and performance can be en-
hanced 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
interface. The firmware in this integrated
circuit can be updated via the Ethernet con-
nection, helping to ensure that its capabili-
ties remain up to date.
Getting Started
What’s Included
Included in the shipping carton are a Model
205 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 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
using a cable terminated with a standard
3-pin female XLR connector. Special ap-
plications may utilize the two remote control
inputs that are accessible using a 3.5 mm
3-conductor 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 connec-
tion by way of a cable-mounted etherCON
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.
Ethernet Connection without PoE
As previously discussed in this guide, the
Model 205 was designed such that the Eth-
ernet connection will provide both data and
Power-over-Ethernet (PoE) power. There
may be situations where the associated
Ethernet switch does not provide PoE pow-
er. In such cases an external PoE midspan
power injector can be used. If the selected
midspan power injector is 802.3af-compat-
ible it should function correctly. Midspan

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 11
MODEL 205
ANNOUNCER’S CONSOLE
units are available from a variety of sources,
including many online retailers.
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
allows the P48 phantom power source to be
enabled or disabled as desired. Details on
configuration settings will be described later
in this guide.
While the Model 205 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 205 by way of the microphone output
connector. 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 mi-
crophone output connector is interfaced with
the microphone input on a broadcast cam-
era, 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
the Model 205’s microphone output connec-
tor. Whenever the Dante main output chan-
nel is muted the microphone signal does

Issue 3, August 2020 Model 205 User Guide
Page 12 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
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 push-
button 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 3.5 mm
3-conductor 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 resis-
tors 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 dam-
age due to static discharge or other extra-
neous signals.) A current flow of less than
one milliampere 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 3.5 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 connec-
tion to common. Refer to Figure 2 for con-
nection details.
Figure 2. 3.5 mm 3-conductor (TRS) remote
control in pinout diagram

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 13
MODEL 205
ANNOUNCER’S CONSOLE
Dante Configuration
For audio to pass to and from the Model
205 requires that several Dante-related
parameters be configured. These configu-
ration settings will be stored in non-volatile
memory within the Model 205’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 Con-
troller are available to support Windows and
OS X® operating systems. The Model 205
uses the Ultimo 4-input/4-output integrated
circuit to implement the Dante functionality.
The Model 205 can also be configured to
meet the requirements of the AES67 stan-
dard. This requires a setting to be enabled
within the Device Info section of the Dante
Controller application.
The three Dante transmitter (Tx) channels
associated with the Model 205’s Dante
interface must be assigned to the desired
receiver channels on associated equipment.
This achieves routing the Model 205’s
three 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 205’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 205’s Dante audio
inputs. The unit provides four audio input
channels. The number utilized will depend
on the specific application. Following the
unit’s headphone source and routing con-
figuration selection these audio signals will
be sent to the Model 205’s 2-channel head-
phone 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 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 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 integrated
circuit. The three Dante transmitter (Tx)
audio output channels have default names
of Main, Talkback 1, and Talkback 2. The
four Dante receiver (Rx) audio input chan-
nels 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.

Issue 3, August 2020 Model 205 User Guide
Page 14 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
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 intensity
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.
Installing STcontroller
STcontroller is available free of charge on
the Studio Technologies’ website (www.
studio-tech.com/stcontroller). STcontroller
versions 2.04.00 and later will fully sup-
port the Model 205. 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 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 config-
ured will appear in the device list. Use the
identify command to allow easy recognition
of a specific Model 205 unit. Double-clicking
on a device name will cause the associated
configuration menu to appear. Review the
current configuration and make any chang-
es that are desired.
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.

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 15
MODEL 205
ANNOUNCER’S CONSOLE
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 input
(receiver) channel 1 will be routed to the
left headphone output channel and pot A
will adjust its level. Dante input (receiver)
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 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/
SidetoneLR
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 ste-
reo pair can be routed to the left and right
headphone output channels. Dante input
channel 1 is routed to the left channel 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 205 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 headphone
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 channels.
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

Issue 3, August 2020 Model 205 User Guide
Page 16 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
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 input channels 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
designed 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 appli-
cable in cases where an extreme headphone
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 exposure
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 input channels will always be pres-
ent on the headphone output. In most on-air
broadcast applications this is the appropriate
setting, ensuring that a minimum amount of
signal is always present. When full mute is
selected moving a level potentiometer 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 counterclockwise or fully
clockwise position will cause the associated
signal to fully mute. Selecting the full mute
mode may be appropriate for applications
where minimizing the chance of audio “leak-
age” is important. This could occur when
during an event the connected 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 side-
tone 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 avail-
able modes will depend on the needs of the
application. If a “full mix” is being provided
to the Model 205’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” audio is being
supplied to the Model 205 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.

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 17
MODEL 205
ANNOUNCER’S CONSOLE
• 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 mi-
crophone output connector will be muted.
Whenever the main button is pressed
the audio signal will become active on
the Dante output channel and the micro-
phone output connector. In addition, the
button’s green LED will light.
• 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 associated
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 ac-
tive-to-inactive. Upon Model 205 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
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.
• Talkback Buttons: In this mode the side-
tone function will be active whenever
either or both of the talkback functions
are active and the audio signal is present
on the talkback 1 and/or talkback 2 Dante
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 out-
put 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
active and its green LED lit. The audio
signal associated with the microphone in-
put will be routed to both the Dante main
output channel and the microphone out-
put connector. Whenever the main button
is pressed the audio signal will mute on
both the Dante main output channel and
the microphone output connector; the but-
ton’s LED will change from green to red.

Issue 3, August 2020 Model 205 User Guide
Page 18 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
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
output connector operate vis-à-vis the talk-
back functions. The system mode can also
impact one facet of the headphone output’s
function. There are three system modes
available. Understanding how each specifi-
cally impacts Model 205 operation will help
to ensure that the desired operation is ob-
tained 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 1 or talkback 2
functions are active. The on-air mode should
be selected for all on-air broadcast applica-
tions when it’s imperative that the “on-air”
audio signal be muted whenever on-air tal-
ent 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 connec-
tor are never muted in response to talkback
function activity. The mic off/off function oper-
ates independently of the talkback functions.
This mode allows the Dante main output
channel to be used, for example, as an addi-
tional 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
associated with the microphone input
will be routed to both the Dante main
output channel and the microphone out-
put connector. Whenever the main button
is pressed and held the audio signal will
mute on both the Dante main output chan-
nel and the microphone output connector
and the button’s LED will change from
green to red. It will stay in this condition
until the main button is released. Upon
Model 205 power up the main button will
be in its inactive state and its red LED will
be lit.
Button Operation – Talkback
The manner in which the two talkback but-
tons function can be configured. One 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 inactive
and the LED associated with each button
will not be lit. Whenever a talkback button
is pressed its associated talkback function
will become active and its green 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 inac-
tive 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 sta-
tions associated with broadcast or produc-
tion 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

Model 205 User Guide Issue 3, August 2020
Studio Technologies, Inc. Page 19
MODEL 205
ANNOUNCER’S CONSOLE
amount of ambient light present in the Model
205’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 205
operation to commence. An Ethernet con-
nection with Power-over-Ethernet (PoE) ca-
pability should have been made. Alternately,
a midspan power injector, in “series” with the
Ethernet connection, should have been put
into place. A microphone and headphones or
earbud should have been connected. Alter-
nately, 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
Control 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 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 transmit-
ter channels on associated Dante-enabled
equipment.
the main and talkback pushbuttons to be
used simultaneously. When selected for the
correct application, the production mode can
prove to be very useful. But it’s not appropri-
ate for on-air use!
Production with Dim
This mode is identical to the production
mode with the exception that the headphone
output reduces in level (“dims”) whenever
the main, talkback 1, or talkback 2 functions
are active. This mode was specifically pro-
vided to minimize the chance that acoustical
feedback will occur in applications where
the headphone output is connected to the
inputs on amplified speakers (or inputs on an
amplifier associated with loudspeakers). In
this mode the level of the headphone out-
put channels is reduced by 18 dB whenever
a main or talkback function is active. This
mode is not appropriate when headphones
are going to be connected to the Model 205!
Remote Control Inputs
There are two remote control inputs which
can be individually configured. Remote Con-
trol Input 1 can be configured to be disabled
(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 disabled
(off), or mimic the action of either the main
or talkback pushbutton switches.
Button Backlight Intensity
The caps (top surfaces) of the three push-
button 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 205 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

Issue 3, August 2020 Model 205 User Guide
Page 20 Studio Technologies, Inc.
MODEL 205
ANNOUNCER’S CONSOLE
seconds the LED identification pattern
will cease and normal Model 205 button
LED and Dante status LED operation will
resume.
Ethernet and Dante Status
LEDs
Three status LEDs are located below the
etherCON RJ45 connector on the Model
205’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 associated
network activity. The SYS LED will light
red upon Model 205 power up to indicate
that the Dante interface is not ready. After
a short interval it will light green to indicate
that it is ready to pass data with another
Dante device. The SYNC LED will light red
when the Model 205 is not synchronized
with a Dante network. It will light solid green
when the Model 205 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
205 is part of a Dante network and is serv-
ing as the clock master. 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 micro-
phone input.
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
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
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 205
Functions within the Dante Controller and
STcontroller software applications allow
a specific Model 205 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 205
unit. On that unit the LEDs associated with
the main and talkback pushbutton switches
will “flash” orange approximately eight
times (the actual on/off status of the buttons
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