Studio Technologies 234 User manual

Copyright © 2020 by Studio Technologies, Inc., all rights reserved
www.studio-tech.com
User Guide
Issue Preliminary 1, June 2020
This User Guide is applicable for serial numbers
M234-00151 and later with main firmware version 1.01 and later
and STcontroller application version 2.10.00 and later.
50686-0620 Issue Preliminary 1
Model 234 Announcer’s Console

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Table of Contents
Revision History ............................................................................. 4
Introduction .......................................................................... Pending
Getting Started ................................................................................ 5
Dante Configuration ......................................................................... 8
Model 348 Configuration ................................................................ 10
Operation ............................................................................. Pending
Technical Notes .............................................................................. 19
Specifications ................................................................................. 24
Appendix A: STcontroller default configuration values ................... 26
Appendix B: 3-Pin Header Connector Details ................................ 27
Appendix C: Model 234 Block Diagram .......................................... 28

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Revision History
Issue Preliminary 1, June 2020:
• Initial preliminary release.

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Introduction
– Pending –
Getting Started
What’s Included
Included in the shipping carton are a Model
234 Announcer’s Console and a printed copy
of this guide. As a device that can be Power-
over-Ethernet (PoE) powered, no external
power source is provided. This is because in
most applications an Ethernet switch with PoE
capability will be utilized. It’s also possible to
connect an external source of 12 volts DC to
power the Model 234. If this is the case then
a power supply would need to be provided
separately.
Connections
In this section signal interconnections will be
made using the connectors located on the
back of the Model 234’s enclosure. One or
two Ethernet connections will be made using
either standard RJ45 patch cables or ether-
CON protected RJ45 plugs. The Ethernet
data connection associated with the primary
RJ45 connector is compatible with Power-
over-Ethernet (PoE). If desired, an Ethernet
connection made to the secondary Ethernet
connector can provide access to a redundant
Dante network. Or it can be utilized as an ac-
tive “loop through” connection associated with
the primary Ethernet connection. If PoE is not
going to be utilized, or a redundant source of
power is desired, a source of 12 volts DC can
be connected by way of a 4-conductor XLR
connector.
A microphone can be connected using a
cable-mounted 3-pin male XLR connector.
A set of headphones, the headset portion of
a broadcast-style headset, or an earpiece
will be connected by way of a ¼-inch plug. If
Figure 1. Model 234 Announcer’s Console front and
back views
desired, the Model 234’s analog microphone
output may be interfaced with other equip-
ment using a cable terminated with a standard
3-pin female XLR connector.
For special applications the Model 234’s
internal circuit boards contain 3-pin “header”
connectors that allow access to various func-
tions. In addition, there are two spare con-
nector locations located on the Model 234’s
back panel. A technician can add connectors
and wire them to the headers such that ap-
plication-specific needs can be supported. For
example, a 6- or 7-pin XLR connector can be
added to support direct connection of broad-
cast-style headsets. Contact closures can be
interfaced to the Model 234’s circuitry, allow-
ing external switches to activate main and
talkback functions. A low-voltage/low-current

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“tally” output associated with the main output
function is also available. Refer to the Techni-
cal Notes section of this guide for details.
One or Two Ethernet Connections
One 1000BASE-T (“GigE”) Ethernet con-
nection is required for Model 234 operation
and can provide both the Ethernet data in-
terface and power, by way of power-over-
Ethernet (PoE), for the Model 234’s circuitry.
A 10BASE-T connection is not sufficient. A
100BASE-TX connection may be adequate
but not optimal. The Model 234 supports Eth-
ernet switch power management, enumerat-
ing itself as a PoE class 3 device.
A second 1000BASE-T (“GigE”) connection
can be made if redundant Dante is desired.
(The Model 234’s network configuration within
the Dante Controller software application
must be set for Redundant for this functional-
ity to be active.) PoE is not supported on the
secondary Ethernet connection. The second-
ary Ethernet connection can also be used as
a “loop through” port such as would be pro-
vided by an Ethernet switch. (This requires
that the Model 234’s network configuration
within the Dante Controller software applica-
tion is set for Switched.) Switched mode is the
default setting but using the secondary port in
this mode for applications other than trouble-
shooting is not recommended. It will function
reliably but “daisy chaining” Ethernet signals
can limit flexibility and present a failure point;
it’s best if each Ethernet device connects
directly to a port on an Ethernet switch.
The Ethernet connections are made by way of
two Neutrik etherCON protected RJ45 con-
nectors that are located on the back of the
Model 234’s enclosure. These allow con-
nection by way of cable-mounted etherCON
connectors or standard RJ45 plugs. The
Model 234’s Ethernet interface supports auto
MDI/MDI-X so that a crossover cable is not
required. The Model 234’s primary Ethernet
connection will enumerate itself as a PoE
class 3 device.
External 12 Volts DC Input
An external source of 12 volts DC can be
connected to the Model 234 by way of the
4-pin male XLR connector which is located
on the back panel. While the requirement for
the external source is nominally 12 volts,
correct operation will take place over a 10
to 18 volts DC range. The Model 234 requires
a maximum of 550 milliamperes (0.55 am-
peres) at 12 volts DC for correct operation.
The DC source should be terminated to a
4-pin female XLR connector with pin 1 nega-
tive (–) and pin 4 positive (+).
If an external power source is required, the
PS-DC-02 power supply, available as an op-
tion from Studio Technologies, is directly com-
patible with the Model 234. Its AC mains input
allows connection to 100-240 volts, 50/60 Hz
with an output of 12 volts DC, 1.5 amperes
maximum. Its DC output is terminated on a
4-pin female XLR connector.
As previously discussed in this guide, an
Ethernet connection that provides power-
over-Ethernet (PoE) can serve as the Model
234’s power source. Alternately, an exter-
nal 12 volts DC source can be connected.
For redundancy, both PoE and the external
source can be connected at the same time. If
both PoE and an external 12 volts DC source
are connected, power will be drawn only from
the PoE supply. If the PoE source becomes
inoperative the 12 volts DC source will pro-
vide the Model 234’s power. No interruption
in operation will occur during a power source
transition.
Analog Microphone Input
Using a configuration selection within the
STcontroller software application, the Model
234’s microphone audio source can be se-
lected. In most cases analog will be selected

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ANNOUNCER’S CONSOLE
and a local microphone will be connected.
Alternately, an audio signal can be provided
by way of a Dante receiver (input) channel. In
this section details on connecting an analog
microphone will be provided. The Model 234
provides a 3-pin female XLR connector, lo-
cated on the back panel, to allow a balanced
dynamic or phantom powered condenser
powered microphone to be connected. The
microphone can be a standalone handheld
(“stick”) type, a larger boom-mounted type,
or can be part of a broadcast-style headset.
The Model 234’s analog microphone input is
directly compatible with balanced, dynamic
or P48-compatible “phantom” powered micro-
phones. A microphone should be connected
such that its associated XLR connector has
pin 1 as common, pin 2 as signal high (+),
and pin 3 as signal low (–). A configuration
setting in the STcontroller application allows
the P48 phantom power source to be enabled
or disabled as desired. Another setting allows
the gain of the preamplifier circuitry associ-
ated with the analog mic input to be selected.
Details on configuration settings will be de-
scribed later in this guide.
While the Model 234 provides an excellent
source of P48 phantom power, it’s possible
that an input on an associated piece of equip-
ment is already providing microphone power.
This input could be connected to the Model
234 by way of the analog microphone output
connector. This would not create a problem
since the circuitry that passes audio from the
Model 234’s analog microphone output con-
nector to the Model 234’s microphone input
connector will also pass microphone without
interruption. This situation could be relevant
in cases where the Model 234’s analog micro-
phone output connector is interfaced with the
microphone input on a broadcast camera, au-
dio console, microphone mixer, remote input/
output rack, or similar equipment. Microphone
inputs on these devices would typically offer
phantom power which in some cases may be
enabled.
Analog Microphone Output
A 3-pin male XLR connector provides an
analog microphone-level output that’s directly
related to the analog microphone input. Tech-
nically the output is identical to the signal
that’s connected to the analog microphone
input but with a solid-state muting circuit in se-
ries with the interconnection. A configuration
choice in the STcontroller application allows
the operation of the microphone output to be
selected. The choices are to have the micro-
phone active at all times or for it to mute when
the Dante main output channel is also muted.
If the analog microphone output is configured
to be active at all times then it will provide
what is effectively an analog “hot mic” output;
a signal that is connected to the analog micro-
phone input will continuously “pass through”
to the analog microphone output. No Model
234 action will impact that signal. If the analog
microphone output is configured to follow the
status of the Dante main output the analog
microphone signal will pass through to the
analog microphone output connector only
when the Dante main output function is ac-
tive. Whenever the Dante main output chan-
nel is muted the microphone signal will not
pass through to the analog microphone output
connector; it is muted in an essentially click-
free manner. Refer to Appendix C for a block
diagram of the analog microphone input and
the analog microphone output circuitry.
The analog microphone output can be con-
nected to balanced (differential) analog mi-
crophone-level inputs on a variety of devices.
This includes microphone input connections
on remote I/O interfaces associated with a
networked audio console. An example of such
an interface would be the Calrec® Hydra2®.
The mic inputs on these devices typically

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offer microphone power, high-quality amplifi-
cation, and conversion to the digital domain.
The output signals of an interface’s pre-amp
channels are transported to the main elec-
tronics or console surface using a fiber optic
interface. In this type of application, the Model
234’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 234’s mi-
crophone input connector to the Model 234’s
microphone output connector. But the signal
does pass through 200-ohm resistors in each
“leg” (pin 2 and pin 3) along with connect-
ing 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 con-
nector. This will slightly raise the theoretical
noise floor of the microphone signal vis-à-vis
a directly connected microphone signal but
shouldn’t impact any real-world applications.
Headphone Output
The Model 234 provides a 2-channel (“ste-
reo”) headphone output interfaced by way of
a 3-conductor ¼-inch phone jack. Devices
such as stereo headphones or dual-channel
(“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
of the plug, the right channel on the ring lead,
and common on the sleeve lead.
It’s also possible to use a single-channel/
monaural (“single-muff”) headset or broad-
cast-type single earbud but in these cases,
care must be taken. If a 3-conductor ¼-inch
plug is used by such 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
234’s headphone output jack the Model 234’s
right headphone output channel will be short-
ed; 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 configured such that it’s routed
to the right headphone output channel. Refer
to the Configuration section later in this guide
for details on using the STcontroller applica-
tion to select the headphone audio routing to
best accomplish this condition.
Dante Configuration
For audio to correctly pass to and from the
Model 234 requires, as a minimum, that sev-
eral Dante-related parameters be configured.
These configuration settings will be stored in
non-volatile memory within the Model 234’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 234
uses the Broadway integrated circuit to imple-
ment the Dante functionality. The Model 234
is compatible with the Dante Domain Manager
(DDM) software application.
Audio Routing
The Model 234’s six Dante transmitter (Tx)
channels must be assigned to the desired
receiver channels on associated equipment.
This will route the Model 234’s main, hot
mic, and four talkback output channels to the
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).

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The number of transmitter flows associated
with a Broadway integrated circuit and, as
such the Model 234, is 16 so no limitation can
exist. These flows can either be unicast, multi-
cast, or a combination of the two. (Note that
in the AES67 mode the transmitter (output)
channels will function in multicast; unicast is
not supported.)
Using Dante Controller, the desired audio
sources need to be routed to the six receiver
(Rx) channels associated with the Model
234’s Dante audio inputs. The exact number
utilized will depend on the specific application.
The six receiver channels are assigned to the
level encoders and can be used for listening
to the associated mix, mix-minus, intercom
channels, or general audio channels.
Unit and Channel Names
The Model 234 has a default Dante device
name of ST-M234- along with a unique suffix.
The suffix identifies the specific Model 234
that is being configured. The suffix’s actual
alpha and/or numeric characters relate to the
MAC address of the unit’s Broadway inte-
grated circuit. The seven Dante receiver (Rx)
audio input channels have default names of
Main 1, Main 2, Talkback 1, Talkback 2,
Talkback 3, Talkback 4, and Mic In. The
eight Dante transmitter (Tx) audio output
channels have default names of Main, Aux,
Talkback 1, Talkback 2, Talkback 3, Talk-
back 4, Phones L, and Phones R. Using
Dante Controller, the default device name and
channel names can be revised as appropriate
for the specific application.
Device Configuration
The Model 234 only supports an audio sam-
ple rate of 48 kHz with no pull-up/pull-down
values available. Encoding choices are PCM
24, PCM 16, and PCM 32, but in virtually all
cases the default selection of PCM 24 would
be appropriate. Clocking and Device Latency
can be adjusted if required but the default
values are typically correct.
Network Configuration – Dante
Redundancy
The Model 234 allows connection of two
Ethernet signals. Two RJ45 jacks are located
on the unit’s back panel and are labeled
Primary-PoE and Secondary. In the network
configuration Dante Redundancy section of
Dante Controller how these ports function
can be selected. The choices are Switched
or Redundant.
If Switched is selected (the factory default)
then the Model 234 will be able to establish
one connection with an Ethernet network.
It doesn’t matter which RJ45 is utilized, al-
though for PoE powering the jack labeled
Primary-PoE must be utilized. The other
RJ45 connection can be used to interconnect
with another piece of networked equipment.
If the Model 234’s network configuration is
Switched ensure that only one of the RJ45
connections on the back panel is connected
to the LAN associated with the Dante devices.
If both of the Model 234’s RJ45 connections
are routed to ports on the same LAN this will
typically “crash” the network! (Although some
of the latest/most-advanced Ethernet switches
will automatically detect and prevent an issue
from occurring.)
If Redundant is selected then Dante’s redun-
dant networking capability will be enabled.
In this case, separate network connections
should be made to the Primary-PoE and Sec-
ondary RJ45 connectors. A personal comput-
er that’s running STcontroller will typically be
associated with the network that is connected
to the Primary-PoE RJ45 jack.
When the Model 234 has been configured for
the Switched network mode one Dante IP ad-
dress will be associated with the network con-
nection that is made to either the Primary-PoE

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or the Secondary RJ45 connections. If the
network configuration has been configured for
Redundant then separate IP addresses and
related network parameters will be assigned
to the Primary-PoE and Secondary Ethernet
ports.
Network Configuration – Addresses
By default, the Model 234’s Dante IP address
and related network parameters will be de-
termined automatically using the DHCP or, if
not available, link-local network protocols. If
desired Dante Controller allows the IP ad-
dress and related network parameters to be
manually set to a fixed (static) configuration.
While this is a more-involved process than
simply letting DHCP or link-local “do their
thing,” if fixed addressing is necessary then
this capability is available. But in this case, it’s
highly recommended that every unit be physi-
cally marked, e.g., directly using a permanent
marker or “console tape,” with its specific stat-
ic IP address or addresses. If knowledge of a
Model 234’s IP address has been misplaced
there is no reset button or other method to
easily restore the unit to a default IP setting.
Note that if the Model 234’s network configu-
ration has been set for Redundant then the
Primary and Secondary Dante IP addresses
and related parameters can be independently
configured. This allows both interfaces to be
configured for automatic, both interfaces to
be manually configured, or one interface to
be automatic and the other to be manually
configured.
AES67 Configuration – AES67 Mode
The Model 234 can be configured for AES67
operation. This requires the AES67 Mode to
be set for Enabled. By default, AES67 mode
is set for Disabled.
Model 234 Clocking Source
While technically the Model 234 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. As such, the check
box for Preferred Master associated with the
Model 234 would not be enabled.
Model 234 Configuration
The STcontroller software application is used
to configure the way in which the Model 234
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 on a personal
computer that’s connected to the related LAN.
Installing STcontroller
STcontroller is available free of charge on the
Studio Technologies’ website (www.studio-
tech.com/stcontroller-application/) and is
compatible with personal computers running
Windows operating systems that are version
7 and later. STcontroller versions 2.05.00
and later are required to fully support the
Model 234. 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 234 units that are to
be configured. Immediately after starting
STcontroller the application will locate all the
Studio Technologies’ devices that it can con-
trol. The one or more Model 234 units to be
configured will appear in the device list. Use
the Identify command to allow easy recogni-
tion of a specific Model 234 unit. Double-
clicking on a device name will cause the
associated configuration menu to appear.
Review the current configuration and make
any changes that are desired.