Studio Technologies 348 User manual

50291-0722, Issue 8
Copyright © 2022 by Studio Technologies, Inc., all rights reserved
studio-tech.com
This User Guide is applicable for serial numbers
M348-00251 and later with main rmware version 2.05 and later
and STcontroller application version 3.08.00 and later.
Also applicable to units with serial numbers
M348-00151 to 00250; see Appendix C for details.
Model 348
Intercom Station
User Guide
Issue 8, July 2022

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Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 3
Model 348
INTERCOM STATION
Table of Contents
Revision History...................................................................................... 4
Introduction.............................................................................................. 5
Getting Started ........................................................................................ 7
Dante Conguration................................................................................ 10
Model 348 Conguration ......................................................................... 11
Operation................................................................................................ 18
Technical Notes ...................................................................................... 26
Specications ......................................................................................... 30
Appendix A–STcontroller Default Conguration Values.......................... 32
Appendix B–3-Pin Header Connector Details ......................................... 33
Appendix C–Di󰀨erences between Model 348 Units as Noted by
Serial Number Range ............................................................................. 34

Issue 8, July 2022 Model 348 User Guide
Page 4 Studio Technologies, Inc.
Model 348
INTERCOM STATION
Revision History
Issue 8, July 2022:
•Documents new Tally Tone Dante transmitter (output) channel.
Issue 7, January 2022:
•Adds Appendix C which documents di󰀨erences in units with serial numbers 00151 to 00250.
Issue 6, December 2021:
•Documents new Listen mode.
Issue 5, May 2021:
•Documents that support is now included for two remote control inputs.
•Documents that a Dante receiver (input) channel can be used as a microphone input source. (In conjunction with this,
Dante receiver (input) channel 16 renamed from “IFB Pgm 8” to “Aux In.”)
•Documents new Talk with Quindar Tones button mode.
•Miscellaneous corrections and improvements.
Issue 4, April 2021:
•Documents that unit now enumerates itself as a class 3 PoE device.
Issue 3, February 2021:
•Claries the Microphone Input – Source function in STcontroller.
Issue 2, August 2020:
•Corrects errors in Issue 1.
Issue 1, January 2020:
•Initial release of complete document.

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 5
Model 348
INTERCOM STATION
Introduction
The Model 348 Intercom Station provides eight
independent talk and listen channels that are com-
patible with Dante
®
audio-over-Ethernet networks.
The desktop unit is designed to serve as an audio
control center for production and support personnel
in numerous applications including on-air television
sports and news broadcasting, live events, theater,
industrial, aerospace, and corporate AV. The Model
348’s channels can be part of virtual “party-lines”
created with other compatible devices or be used
directly in point-to-point intercom implementations.
The range of resources makes it simple to use the
Model 348 locally, or as part of a REMI or “At-Home”
geographically diverse implementation. In addition
to intercom applications, the unit can create multiple
independent IFB (talent cue) channels. Other appli-
cations may benet from the Model 348 user’s ability
to easily create monitor mixes from the eight input
audio channels. This makes the unit a viable choice
for listen-only scenarios.
Over a standard IP network, multiple Model 348 units
can be used in party-line (PL) intercom applications
with help from external Dante-enabled audio devices
such as the Studio Technologies’ Model 5421 or Model
5422A Dante Intercom Audio Engines. Model 348
units can also be used “point-to-point” or interfaced
with Dante-compatible matrix intercom systems. The
Model 348 includes two Neutrik etherCON RJ45
jacks which allow interfacing with single or redundant
Dante Ethernet networks. The primary network con-
nection can provide power to the unit using standard
Power-over-Ethernet (PoE). It can also be powered
using a 12 volts DC source that is connected using a
broadcast-standard 4-pin XLR connector.
The Model 348 supports connection of a broadcast- or
intercom-style headset that use a dynamic or electret
(DC powered) microphone. The unit provides both
a 5-pin female XLR and a 3.5 mm TRRS connector
allowing for a traditional “pro” or a contemporary
gaming headset to be utilized. In addition, the Studio
Technologies’ GME-3-12 electret gooseneck micro-
phone can be directly connected using the 1/4-inch
jack located on the top of the unit’s enclosure. A
low-noise microphone preamplier and associated
voltage-controlled-amplier (VCA) dynamics controller
(compressor) ensures excellent headset and goose-
neck microphone audio quality while minimizing the
chance of signal overload.
A Dante receiver (input) channel can also be used as
the talk audio source. This was specically included
to allow two Model 348 units to “work” together to
support more than eight talk channels. A pushbutton
switch allows users to directly select the active talk
audio source. Choices include the headset mic, the
gooseneck mic, or the Dante Aux In receiver (input)
channel.
All Model 348 operating features are congured 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 available, free of charge, from the
Studio Technologies’ website. Versions are available
Figure 1. Model 348 Intercom Station front and back views

Issue 8, July 2022 Model 348 User Guide
Page 6 Studio Technologies, Inc.
Model 348
INTERCOM STATION
that are compatible with the Windows
®
and macOS
®
operating systems. STcontroller is a fast and simple
means of conguring, revising, saving, and loading a
unit’s operating parameters.
The Model 348’s front panel includes eight rotary
controls (“encoders”) which are used to adjust the
level of the eight Dante monitor input signal sources.
Using RGB (red-green-blue) LEDs, the knob of each
encoder is illuminated and can display if a channel is
muted, indicate if a signal is present on the associ-
ated audio input, and light when an in-band (20 kHz
tone) call signal is detected. The user can monitor the
Dante audio inputs by means of a headset, a built-in
speaker, or two Dante transmitter (output) channels.
Two additional rotary encoders are used to control
the overall audio level and on or o󰀨 (mute) status of
the signals being sent to the headset and speaker
outputs. A modern class-D amplier integrated circuit
drives the speaker e󰀩ciently while preserving audio
delity.
Extensive conguration choices allow the operation of
the eight pushbutton switches and associated output
channels to be optimized to meet the needs of an
extensive range of specialized applications. They
can be independently congured for talk (intercom),
IFB (talent cue), call signal (20 kHz tone), and other
related actions. The buttons can also be congured
to provide an “all-call” action associated with the talk
and IFB functions.
A special button conguration mode supports the gen-
eration of talk channels that include Quindar Tones.
These are short-duration “intro” and “outro” audio
signals that were traditionally used in space programs
to control the on and off status of transmitters. In
recent years these tones have taken on the function
of providing an audible indication of when Capsule
Communicator (CapCom) transmissions are taking
place. These ubiquitous “beeps” have become syn-
onymous with ground-to-astronaut communications.
For performance conrmation an integrated sidetone
function allows audio coming from the active talk
audio source to be returned to the headset output.
An audible alert, using the internal speaker, can be
generated in response to a call signal. Provision has
been made such that a technician can “customize” the
Model 348’s hardware. Option kits, purchased sepa-
rately, can be added to support additional functions.
These include adding two remote control inputs which
can be congured to mimic the action of talk buttons.
The Model 348’s compact enclosure has overall
dimensions of 6.5 inches wide (16.5 cm), 2.5 inches
high (6.4 cm), and 4.6 inches deep (11.7 cm). Weigh-
ing 1.8 pounds (0.8 kg), the enclosure is made of steel
to provide some “heft” to minimize the chance of inad-
vertent movement. The Model 348’s main application
rmware can be updated using the USB port on the
back of the unit; the Dante rmware can be updated
via an Ethernet connection.
Ethernet Data and PoE
The Model 348 connects to one or two local
area networks (LANs) by way of two twisted-pair
Ethernet interfaces. The 1000BASE-T Gigabit Ethernet
(GigE) interconnections are made by way of Neutrik
®
etherCON RJ45 jacks. While compatible with stan-
dard RJ45 plugs, etherCON allows a ruggedized
and locking interconnection for harsh or high-reliabil-
ity environments. The two Ethernet interfaces can
be congured, using the Dante Controller software
applications, to serve in Switched or Redundant
modes.
The Model 348’s operating power can be provided
by way of the Primary-PoE Ethernet interface using
the 802.3af Power-over-Ethernet (PoE) standard.
PoE allows fast and efficient interconnection with
the associated data network. Alternately, an external
source of nominal 12 volts DC can be connected to
power the unit. If both are connected then PoE will
be the active power source.
Dante Audio-over-Ethernet
Audio data is sent to and received from the Model
348 using the Dante audio-over-Ethernet media
networking technology. As a Dante-compliant de-
vice, the Model 348’s 11 Dante transmitter (output)
audio channels and 16 Dante receiver (input) audio
channels can be assigned (routed or “subscribed”)
using the Dante Controller software application. The
Dante transmitter and receiver channels support 32
Dante ows, 16 in each direction. The digital audio’s
bit depth is up to 32 with a sample rate of 48 kHz.
Bi-color LEDs, located on the unit’s back panel, pro-
vide status indications of the Ethernet network and
Dante interface performance.

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 7
Model 348
INTERCOM STATION
The Model 348 is compliant with the AES67 interop-
erability standard. In addition, the unit is compatible
with Audinate’s
®
Dante Domain Manager™ (DDM)
software application.
Audio Quality
The Model 348’s audio performance is completely
“pro.” A low-noise, wide dynamic-range micro-
phone preamplifier and associated voltage-
controlled-amplifier (VCA) dynamics controller
(compressor) ensure that headset and gooseneck
microphone audio quality is preserved and minimiz-
es the chance of signal overload. The output of the
microphone preamp and compressor is routed to
an analog-to-digital conversion (ADC) section that
supports sampling rates of 48 kHz. A Dante receiv-
er (input) channel can be used as an alternate talk
source. The selected talk audio signal routes through
a 32-bit micro-processor and on to the Dante inter-
face section where it is packetized and prepared for
transport over Ethernet. A total of 11 Dante transmitter
(output) channels are provided: one each associated
with the unit’s eight channels, two monitor output
channels, and one hot mic output channel.
Audio input signals arrive via 16 Dante receiver (input)
channels and pass into the Model 348’s 32-bit micro-
processor. Eight input channels are associated with
the monitor section while the other eight inputs are
used as program sources for the IFB (talent cue) func-
tions. One of the latter input sources can also serve
as a talk audio source. All channel routing, headphone
and monitor level control, IFB creation, and sidetone
functionality is performed within the digital domain.
This provides exibility, allows precise level control,
and eliminates the need for analog audio signals from
having to pass through electromechanical level con-
trols. The audio signals destined for the headphone
and speaker outputs are sent to high-performance
digital-to-analog converter circuitry and then on to
robust driver circuitry.
Future Capabilities and Firmware
Updating
The Model 348 was designed so that its capabilities
and performance can be easily enhanced in the future.
A USB connector, located on the unit’s back panel,
allows the application rmware (embedded software)
to be updated using a USB ash drive. The Model 348
uses the Broadway™ integrated circuit from Audinate
to implement its Dante interface. The rmware in this
integrated circuit can be updated via an 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 348
Announcer’s Console and instructions on how to
obtain an electronic 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
348. 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
348’s enclosure. In addition, many applications will
utilize the Studio Technologies’ GME-3-12 gooseneck
microphone which will be attached via the 1/4-inch
jack located on the top surface of the unit.
One or two Ethernet connections will be made using
either standard RJ45 patch cables or etherCON
protected RJ45 plugs. The Ethernet data connection
associated with the Primary-PoE RJ45 jack is com-
patible with Power-over-Ethernet (PoE). If desired,
an Ethernet connection made to the Secondary
Ethernet receptacle can provide access to a Redun-
dant Dante network. Or it can be utilized as an active
“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 dual-channel or single-channel (dual- or single-ear)
headset can be connected using a cable-mounted
5-pin male XLR connector. Alternately, a “computer”
headset with a 3.5 mm 4-conductor TRRS plug can
be used. An electret gooseneck microphone that has
an integrated 1/4-inch plug can be connected.
For special applications, the Model 348’s internal
circuit boards contain 3-pin “header” connectors that
allow access to several functions. In addition, there’s

Issue 8, July 2022 Model 348 User Guide
Page 8 Studio Technologies, Inc.
Model 348
INTERCOM STATION
one spare connector location on the Model 348’s back
panel. A technician can add a connector and wire it
to the headers such that application-specic needs
can be supported. For example, two contact closures
can be interfaced to the Model 348’s circuitry allowing
external switches to activate two of the button func-
tions. Refer to the Technical Notes section for details.
One or Two Ethernet Connections
One 1000BASE-T Gigabit Ethernet (GigE) connec-
tion is required for Model 348 operation. If available
and connected to the Primary-PoE RJ45 jack, this
connection can provide both the Ethernet data
interface and power for the Model 348’s circuitry.
A 100BASE-TX (100 Mb/s) connection may be
adequate but not optimal. A 10BASE-T (10 Mb/s)
connection is not su󰀩cient.
A second 1000BASE-T Gigabit Ethernet (GigE) con-
nection can be made if Redundant Dante is desired.
The Model 348’s network conguration must be set for
Redundant for this functionality to be active. PoE is not
supported on the Secondary Ethernet connection. The
Secondary Ethernet interface can also be used as a
“loop through” connection such as would be provided
by an Ethernet switch. This requires that the Model
348’s network configuration be set for Switched.
Using the secondary port in this mode for applications
other than troubleshooting is not recommended. It will
function reliably but “daisy chaining” Ethernet signals
can limit exibility and present a failure point.
The Ethernet connections are made by way of two
Neutrik etherCON protected RJ45 jacks that are locat-
ed on the back of the Model 348’s enclosure. These
allow connection by way of cable-mounted etherCON
connectors or standard RJ45 plugs. The Model 348’s
Ethernet interfaces support auto MDI/MDI-X so that
crossover cables are not required. The Model 348’s
Primary Ethernet connection enumerates itself as
a class 3 device. As such, a PoE power-sourcing-
equipment (PSE) port could be required to supply up
to 12.94 watts of power.
External 12 Volts DC Input
An external source of 12 volts DC can be connected
to the Model 348 by way of the 4-pin male XLR con-
nector 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 volt range. The Model 348 requires a maximum
of 1.1 amperes at 12 volts DC for correct operation.
The DC source should be terminated to a 4-pin
female XLR connector with pin 1 negative (–) and
pin 4 positive (+).
If an external power source is required, the PS-DC-02
power supply, available as an option from Studio
Technologies, is directly compatible with the Model
348. 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, an Ethernet connection that
provides power-over-Ethernet (PoE) can serve as the
Model 348’s power source. Alternately, an external 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 provide the
Model 348’s power. No interruption in operation will
occur during a power source transition.
Headset Connections
The Model 348 allows two di󰀨erent types of headsets
to be connected. A 5-pin female XLR connector, locat-
ed on the Model 348’s back panel, allows connection
of a standard broadcast- or intercom-style communi-
cations headset. A 3.5 mm 4-conductor TRRS jack,
also located on the back panel, allows a computer
gaming headset to be directly connected. The Model
348’s two headset connectors are electrically wired
in parallel. As such, only one type of headset should
be connected at one time.
Headset A
The Model 348 provides a 5-pin female XLR con-
nector that interfaces with the microphone and head-
phone connections of a single- or dual-ear intercom
or broadcast-style headset. The connector is labeled
Headset A. Refer to Figure 2 for connection details.
The microphone input connections are compatible
with most unbalanced dynamic or electret (low-
voltage DC-powered) microphones. A balanced
dynamic microphone should, in most cases, also
function correctly if its signal – (low) is connected to
Model 348’s mic in –/shield connection. No support
is provided for microphones that require P12 or P48
phantom power.

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 9
Model 348
INTERCOM STATION
To allow users of stereo (dual-earpiece or
“double-mu󰀨”) headsets to hear a monaural version
of the two headphone output channels does not
require special wiring of the 5-pin male XLR mating
connector. The headset’s left headphone channel
should always be wired to pin 4 and the right head-
phone channel to pin 5. Conguration choices using
the STcontroller software application, as discussed
in later sections, can be used to create the desired
monaural output. It’s important not to connect together
(short) pins 4 and 5 of the headset’s connector as
damage to the Model 348’s output circuitry could
result.
A monaural (single-earpiece or “single-mu󰀨”) headset
should be wired such that its headphone is wired only
to pin 4; pin 5 should be remain unused. Congura-
tion choices, provided in STcontroller, can be used to
create a monaural output.
It’s possible that some Beyerdynamic headset
interconnecting cable assemblies will terminate its
earpiece’s left and right connections opposite from
what the Model 348 and other broadcast equipment
require. These cables may terminate the left earpiece
to pin 5 of the 5-pin male XLR connector and the right
earpiece to pin 4. If this condition is present it will
require reversing or “ipping” the two wires in a head-
set’s connector such that the left earpiece connects
to pin 4 and the right earpiece to pin 5.
If a separate microphone and pair of stereo or mon-
aural headphones need to be connected an adapter
cable assembly must be fabricated. It would con-
sist of a 5-pin male XLR connector wired to both a
3-pin female XLR connector for the microphone and
a 3-conductor 1/4-inch or 3.5 mm TRS jack for the
headphones. In this scenario, the microphone would,
in most cases, be a dynamic type as the Model
348 provides only low-voltage DC electret power.
Phantom-powered (P12 or P48) microphones would
not be compatible. Most hand-held or “stick” micro-
phones are dynamic and should function correctly.
Headset B
The Model 348 also allows direct connection of
gaming headsets that are ubiquitous in the personal
computer world. The 3.5 mm 4-conductor TRRS jack,
labeled Headset B, is compatible with the CTIA™/AHJ
conguration standard which has the headphone left
channel on the tip connection, the headphone right
channel on the ring 1 connection, common on the
ring 2 connection, and the microphone on the sleeve
connection.
Compatible headsets are readily available, typically
described as personal computer or gaming headsets.
The microphones used in these headsets are elec-
tret type which require a low-voltage DC source for
operation. The Model 348 is able to provide this power
and requires only that the appropriate setting in the
STcontroller software application be selected. Refer
to Figure 3 for a detailed description of the compatible
TRRS plug.
Figure 2. Headset A connection pinout chart
Figure 3. Headset B (TRRS) connection pinout chart
Gooseneck Microphone
A threaded combination bushing/3-conductor 1/4-inch
jack is incorporated into the top panel of the Model
348. This allows direct connection of the Studio Tech-
nologies’ GME-3-12 Gooseneck Microphone. This
unidirectional, electret microphone was designed
specically to maximize performance in intercom and
related applications. The RTS/Telex/Bosch MCP-90-
series is also directly compatible and will perform
well. The two main requirements for the gooseneck
microphone are that it contain an electret microphone
and the interconnection be in the form of a 1/4-inch
3-conductor plug with integrated threads that have a
pitch 7/16-20 UNF.

Issue 8, July 2022 Model 348 User Guide
Page 10 Studio Technologies, Inc.
Model 348
INTERCOM STATION
The 3-conductor 1/4-inch jack associated with the
Model 348’s gooseneck bushing has a tip connection
that is used for both microphone audio as well as for
supplying the low-voltage DC needed for powering the
electret microphone. The ring connection is used for
the microphone low signal and the sleeve connection
is chassis ground. Within the Model 348’s circuitry the
ring and sleeve connections are connected together
as well as being “tied” (connected) to the chassis.
The Model 348’s gooseneck bushing includes a hex
head socket set screw with a thread pitch of 4-40
UNC. This allows the gooseneck microphone to be
secured into the bushing by simply tightening the set
screw against the microphone using a 5/64 hex driver.
In many cases, especially in applications where the
Model 348 will be moved from venue-to-venue, it will
not be optimal for the hex screw to be utilized. This is
because the gooseneck microphone may need to be
removed and stored for transit. In this case, the set
screw should be removed and stored.
Dante Conguration
For audio to correctly pass to and from the Model
348 requires, as a minimum, that several Dante-
related parameters be configured. These configu-
ration settings will be stored in non-volatile memory
within the Model 348’s circuitry. Configuration will
typically be done with the Dante Controller software
application which is available for download, free of
charge, at audinate.com. Versions of Dante Controller
are available to support both the Windows and the
macOS operating systems. The Model 348 uses the
Broadway integrated circuit to implement the Dante
functionality. The Model 348 is compatible with the
Dante Domain Manager (DDM) software application.
Audio Routing
The Model 348’s 11 Dante transmitter (output) chan-
nels must be assigned to the desired Dante receiver
(input) channels on associated equipment. This will
route the Model 348’s eight talkback, two monitor,
and one hot mic output channels to the devices that
will be “listening” to them. Within Dante Controller a
“subscription” is the term used for routing a transmit-
ter ow (a group of up to four output channels) to a
receiver ow (a group of up to four input channels).
The number of transmitter ows associated with a
Broadway integrated circuit and, as such, the Model
348, is 16 so there’s a minimal chance of a ow limita-
tion. These ows can either be unicast, multicast, or a
combination of the two. (Note that in the AES67 mode
the Dante transmitter (output) channels will function
in multicast; unicast is not supported.)
Using Dante Controller the desired audio sources
need to be routed to the Model 348’s 16 Dante
receiver (input) channels. The exact number utilized
will depend on the specic application. The rst eight
Dante receiver (input) channels are automatically
assigned to the rotary encoders and can be used
for listening to the associated intercom channels or
as general-purpose audio channel monitoring. The
second set of eight Dante receiver (input) channels
are associated with the IFB (talent cue) functions.
They will be utilized only with channels that have their
IFB function enabled. The last Dante receiver (input)
channel, labeled Aux In, can be used as both an IFB
program source and a mic input.
Unit and Channel Names
The Model 348 has a default Dante device name
of ST-M348- along with a unique su󰀩x. The su󰀩x
identies the specic Model 348 that is being con-
figured. The suffix’s actual alpha and/or numeric
characters relate to the MAC address of the unit’s
Broadway integrated circuit. The 16 Dante re-
ceiver (input) audio channels have default names
of Ch 1 – Ch 8, IFB Pgm 1 – IFB Pgm 7, and
Aux In. The 12 Dante transmitter (output) audio
channels have default names of Ch 1 – Ch 8, Mon A,
Mon B, Hot Mic, and Tally Tone. Using Dante
Controller the default device name and channel
names can be revised as appropriate for the specic
application.
Device Conguration
The Model 348 only supports an audio sample
rate of 48 kHz with no pull-up/pull-down values avail-
able. 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 Conguration – Dante
Redundancy
The Model 348 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

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 11
Model 348
INTERCOM STATION
the network conguration 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 348 will be able to establish one connection
with an Ethernet network. It doesn’t matter which
RJ45 jack is utilized, although for PoE powering the
jack labeled Primary-PoE must be utilized. The other
RJ45 jack can be used to interconnect with another
piece of networked equipment. If the Model 348’s
network conguration is Switched ensure that only
one of the RJ45 jacks on the back panel is connected
to the LAN associated with the Dante devices. If both
of the Model 348’s RJ45 jacks are routed to ports on
the same LAN this will typically “crash” the network!
(Although some of the latest/most advanced Ether-
net switches will automatically detect and prevent an
issue from occurring.)
If Redundant is selected then Dante’s redundant net-
working implementation will be enabled. In this case,
separate network connections should be made to the
Primary-PoE and Secondary RJ45 jacks. A personal
computer that’s running STcontroller will typically be
associated with the network that is connected to the
Primary-PoE RJ45 jack.
When the Model 348 has been configured for the
Switched network mode one Dante IP address will be
associated with the network connection that is made
to either the Primary-PoE or the Secondary RJ45
jacks. If the network conguration has been cong-
ured for Redundant then separate IP addresses and
related network parameters will be assigned to the
Primary-PoE and Secondary Ethernet ports.
Network Conguration – Addresses
By default, the Model 348’s Dante IP address and
related network parameters will be determined auto-
matically using the DHCP or, if not available, link-local
network protocols. If desired Dante Controller allows
the IP address and related network parameters to be
manually set to a xed (static) conguration. While
this is a more-involved process than simply letting
DHCP or link-local “do their thing,” if xed addressing
is necessary then this capability is available. But in
this case, it’s highly recommended that every unit be
physically marked, e.g., directly using a permanent
marker or “console tape,” with its specic static IP
address. If knowledge of a Model 348’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 348’s network conguration has
been set for Redundant then the Primary and Second-
ary Dante IP addresses and related parameters can
be independently congured. This allows both to be
automatic, both to be manually congured, or one to
be automatic and the other to be manually congured.
AES67 Conguration – AES67 Mode
The Model 348 can be congured for AES67 oper-
ation. This requires the AES67 Mode to be set for
Enabled. By default, AES67 mode is set for Disabled.
Model 348 Clocking Source
While technically the Model 348 can serve as a Leader
clock for a Dante network (as can all Dante-enabled
devices) in virtually all cases the unit will be congured
to receive “sync” from another device. As such, the
check box for Preferred Leader associated with the
Model 348 would not be enabled.
Model 348 Conguration
The STcontroller software application from Studio
Technologies is used to congure the way in which
the Model 348 functions. No DIPswitch settings or
other local actions are used to congure the unit. This
makes it imperative that STcontroller be available for
convenient use on a personal computer that’s con-
nected to the related LAN.
Installing STcontroller
STcontroller is available free of charge on the Studio
Technologies’ website (studio-tech.com). Versions are
available that are compatible with personal computers
running selected versions of the Windows and macOS
operating systems. 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 348
units that are to be congured.
Immediately after starting STcontroller the applica-
tion will locate all the Studio Technologies’ devices
that it can control. The one or more Model 348 units
to be congured will appear in the device list. Use
the Identify command to allow easy recognition of a
specic Model 348 unit. Double-clicking on a device
name will cause the associated conguration menu

Issue 8, July 2022 Model 348 User Guide
Page 12 Studio Technologies, Inc.
Model 348
INTERCOM STATION
to appear. Review the current conguration and make
any changes that are desired.
Changes made using STcontroller will be immediately
reected in the unit’s operation; no Model 348 reboot
is required. Each time a change is made the eight but-
tons on the Model 348’s front panel will ash orange in
a distinctive pattern to indicate that a command from
STcontroller has been received.
General Menu Page
The following conguration selections are available
in the General menu selections tab:
Microphone Input – Source
Choices are Headset, Gooseneck, and Dante Aux In
The microphone associated with a connected head-
set, the gooseneck microphone, or the Dante Aux In
channel can be selected as the Model 348’s micro-
phone (talk) audio source. STcontroller can be used
to select the desired microphone source, as can
the pushbutton switch located on the Model 348’s
front panel. All three sources are available for use in
“real-time.” This eld provides two functions, display-
ing the active microphone source as well as allowing
the selection of it.
Microphone Input – Headset Mic Power
Choices are Enabled and Not Enabled (box checked
or not)
A headset can be connected by way of a 5-pin female
XLR connector, labeled Headset A, or a 3.5 mm
4-conductor TRRS jack, labeled Headset B. Enable
the headset microphone power check box if the con-
nected headset has an electret microphone which
requires a source of low-voltage DC for operation. In
virtually all cases gaming or computer headsets that
use a 3.5 mm TRRS plug will require microphone
power. Most broadcast headsets that terminate on a
5-pin male XLR connector will incorporate a dynam-
ic (non-powered) microphone. In this case, do not
enable headset microphone power. The on/o󰀨 status
of the headset microphone power is displayed by way
of an LED, red in color, that is located on the Model
348’s back panel below the Headset A connector.
Note that the Model 348 cannot supply P12 or P48
phantom power that may be required by balanced
condenser (capacitor) microphones. This should not
pose an issue as phantom-powered microphones are
essentially never associated with communications- or
intercom-style headsets that would be used for Model
348 applications.
Microphone Input – Headset Mic Gain
Choices are 26 dB, 32 dB, 38 dB, 44 dB, and 50 dB
To match the requirements of a microphone asso-
ciated with a headset, the gain of the microphone
preamplier can be selected from among ve choices.
The selected gain is applied no matter if the headset
is connected using the Headset A or the Headset B
connector. The compressor active LED, located below
the Headset A connector, can act as a guide when
setting the microphone preamplier gain. When the
headset mic is selected as the Model 348’s micro-
phone source and a voice signal at a normal level is
present on the connected headset’s microphone the
compressor active LED should light intermittently.
If, for example, it rarely lights and the gain is set to
38 dB, it might be a good idea to change the setting
to 44 dB. If the compressor active LED is lit fully
during normal talking and the gain is set for 44 dB
or 50 dB, a change to one of the lower values might
be warranted. There’s no “hard and fast” rule as to
which gain setting is appropriate. But unless other-
wise indicated, 38 dB is typically a good initial choice
for a headset that uses a dynamic microphone while
32 dB would be appropriate for a headset that includes
an electret microphone.
Microphone Input – Gooseneck Mic Gain
Choices are 12 dB, 18 dB, 24 dB, 30 dB, and 36 dB
When the gooseneck microphone is selected as the
Model 348’s microphone audio source the gain of the
microphone preamplier will operate from among ve
congurable choices. The compressor active LED,
located adjacent to the Headset A connector, can act
as a guide when setting the gooseneck preamp gain.
When a voice signal at a normal level is presented
to the gooseneck microphone the compressor active
LED should light intermittently. If, for example, the
LED rarely lights and the gain is set to 18 dB, it might
be a good idea to change the setting to 24 dB or
30 dB. If the compressor active LED is lit fully during
normal talking and the gain is set for 30 or 36 dB, a
change to one of the lower values might be warranted.

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 13
Model 348
INTERCOM STATION
Microphone Input – Dante Aux In Trim
Choices are –12 dB, –6 dB, 0 dB, 6 dB, and 12 dB
When the Dante Aux In receiver (input) channel is
selected as the Model 348’s microphone audio (talk)
source its level can be congured from among ve
choices. This allows the level of the signal associated
with the Aux In Dante receiver (input) channel to be
matched to the needs of the button functions. Two of
the congurable settings allow the signal level to be
reduced, one setting maintains the input level as is,
while the other two allow an increase in the signal
level. In most cases, selecting 0 dB, neither subtract-
ing nor adding gain, will be appropriate. This setting
was provided to support situations where the Aux In
channel has a nominal level of –20 dBFS. But this may
not always occur and the conguration choice should
be changed as required to achieve optimal operation.
Microphone Input – Dante Aux In as Mic
In Source
Choices are Disabled and Enabled
A congurable setting determines whether or not the
Dante Aux In receiver (input) channel can be used as
a microphone source.This conguration should only
be selected for Enabled if an external source of talk
audio, typically provided by a second Model 348 unit,
is going to be implemented.However, in most cases,
it will not be utilized and selecting Disabled would
make the user experience most simple. In this case,
pressing the microphone source select pushbutton
switch on the Model 348’s front panel will not allow
the Aux In channel to be selected.
Headset – Sidetone Level
Choices are O, Low, Medium Low, Medium,
Medium High, and High
As a user condence signal, audio from the select-
ed microphone source can be routed to the left and
right headphone channels of the headset interface.
Sidetone audio can be present whenever an applica-
ble button function is active on any or all of the unit’s
eight channels. An applicable function is one that
uses the headset’s mic, the gooseneck microphone,
or the Aux In. These include Talk, Talk with 18 kHz
Tone, IFB, and Talk with Quindar Tones. There is no
denitive sidetone level setting. One that provides the
user with a su󰀩cient amount of their own talk audio
such that they are comfortable should be su󰀩cient.
Headset – Dim
Choices are 0 dB,6 dB,12 dB, and 18 dB
This headset dim function allows the output of the two
headset output channels to be “dimmed” (attenuated
or reduced in level) in certain circumstances. The
function is provided for special applications where
the headset’s left and right headphone outputs are
connected to an external amplier or set of amplied
speakers. Normally, whenever a talk or IFB function is
active on one or a combination of the eight channels
the level of the headset’s headphone output channels
would not change. As such, the default dim value has
been selected to be 0 dB. But if an adapter cable was
fabricated and the headset’s headphone output chan-
nels were connected to audio playback devices that
presented audio energy in the same physical vicinity
as the active microphone then acoustic feedback is
possible. To prevent this from happening selecting a
dim conguration of 6, 12, or 18 dB might be desirable.
Speaker – Source
Choices are O, Monitor A, and Monitor B
The Model 348 includes an internal loudspeaker of
which an audio source can be selected from the two
audio “mix” buses that are named Monitor A or Monitor
B. These buses contain audio content that is specied
in the individual conguration choices for the eight
audio input channels. The speaker can be designated
to monitor either of these buses or to not be active.
Speaker – Dim
Choices are 0 dB, 6 dB, 12 dB, and 18 dB
The output level of the Model 348’s internal loud-
speaker will be automatically “dimmed” (attenuated
or reduced) whenever a talk or IFB function is active
on any of the eight channels. This will help prevent
audio from the loudspeaker from interfering with the
operation of the selected microphone. Interference
could be in the form of unwanted audio content or
even acoustical feedback. It’s typical for a user who
listens at a higher output level to select a dim value
that provides more reduction. In almost all cases
a selection of other than 0 dB (no dim) would be
appropriate.

Issue 8, July 2022 Model 348 User Guide
Page 14 Studio Technologies, Inc.
Model 348
INTERCOM STATION
Dante Monitor Outputs – Mode
Choices are O, Pre-Fader, and Post-Fader
The Model 348 provides two Dante transmitter (out-
put) channels, Monitor A and Monitor B, that are
intended for use by other pieces of equipment such
as amplied speakers, audio consoles, and matrix
intercom systems. These two channels can be cong-
ured as a group to function from among three choices.
Off: In this mode, the two Dante monitor output
channels, Monitor A and Monitor B, will not have
audio present on them. The Dante Controller software
application will still indicate that the channels are
present but no audio will be routed to them from the
Model 348’s circuitry.
Pre-Fader: In this mode, the audio level and on/o󰀨
status of Dante monitor output channels will not be
impacted by the Model 348’s monitor output rotary
encoder. To clarify, neither level adjustment or on/o󰀨
control will occur. This mode is appropriate when the
monitor output channels are going to be utilized by
devices that incorporate, if required, level control and/
or signal muting capability.
Post-Fader: In this mode, the audio level and on/o󰀨
status of Dante transmitter (output) channels Monitor
A and Monitor B will follow the action of the Model
348’s monitor output rotary encoder. This mode is
applicable if the device or devices utilizing the Dante
monitor outputs require that the level of the source
signals be adjusted and/or muted using the Model
348’s resources.
Dante Monitor Outputs – Dim
Choices are 0 dB, 6 dB, 12 dB, and 18 dB
Whenever a talk or IFB function is active the Model
348 will invoke a dim (attenuation) function. This is
designed to help achieve maximum intelligibility and
minimize the chance of acoustic feedback when
loudspeakers are associated with either or both Dante
monitor outputs Monitor A or Monitor B. A dim setting
of 0 dB means that the signal level on the Dante
monitor outputs will remain unchanged. (The signal
will be attenuated by 0 dB which is no attenuation!)
System – Level Control Position Display
Choices are O and On
For user assistance the orange LEDs contained within
the eight pushbutton switches can be utilized in a “bar
graph” format to give a general indication of the set-
tings of the ten rotary encoders. If enabled, whenever
the setting of a rotary encoder is changed the LEDs
eight buttons will momentarily light. In most cases it
would be advantageous to enable this function.
System – Signal Present Display
Choices are O and On
The top surface of the ten rotary encoders can light
as an indication of the level of the audio associated
with a specic encoder and related function. This is
accomplished by the incorporation of RGB (red-green-
blue) LEDs located within each rotary encoder. The
knob will light green when signal levels are in the
normal range, yellow when the signal level is greater
than normal, and red when the signal level is at risk
of degrading audio performance. Note that even if
the Signal Present Display function is disabled (O󰀨)
the rotary encoders will still display their normal and
muted state using LED illumination.
System – LED Intensity
Choices are Low and High
The eight pushbutton switches, ten rotary encoders,
and mic source selection function have LED indicators
associated with them. The LED intensity conguration
choice allows the overall intensity of these LEDs to
be selected. Typically, deciding which choice, low or
high, is optimal will depend on the amount of ambient
light present where the Model 348 is located.
System – Headset and Monitor Outputs
Follow Mic Source
Choices are O and On
This function allows the muted/unmuted state of the
headset’s headphone outputs, the Dante monitor
outputs (when configured for post-fader), and the
speaker output to automatically be determined by the
user’s choice of which microphone is active. This is a
sophisticated function that can prove useful for users
who are frequently switching between the headset
microphone, the gooseneck microphone, and/or the
Aux in. When the function is enabled, whenever the
microphone source selection changes from goose-
neck or Aux In to headset the Dante monitor output
channels (only when congured for post-fader) and
the speaker will mute. And whenever the microphone
source selection changes from headset to gooseneck
or Aux In the headset’s headphone outputs will mute.

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 15
Model 348
INTERCOM STATION
This helps to ensure that unwanted audio isn’t present
as a specic microphone source is selected.
System – Hot Mic
Choices are O and On
A Dante transmitter (output) channel is available
which provides a hot mic (always active) function.
The source of the Hot Mic output channel will be
the selected microphone source, either the headset
microphone, the gooseneck microphone, or the Aux
In Dante receiver (input) channel. This can be very
useful but must be enabled only when an application
explicitly requires that the hot mic output be active.
Note that even if the hot mic output is not enabled
(function congured for O󰀨) the Dante Hot Mic trans-
mitter (output) channel will still be present. It will
always appear in the list of available channels as
shown in Dante Controller. But no audio will be
present on the channel unless the output has been
enabled (function congured for On).
System – Monitor A Call Tone Level
Choices are O, Low, Medium, and High
The Model 348 is capable of generating an audible
alerting signal when a call signal is detected on a
channel that is assigned to the Monitor A audio bus.
This signal consists of repeating sequences of three
short bursts of sine wave audio that are output by
way of the speaker. The level range can be selected
from among three choices as well as being selected
for o󰀨 (muted).
System – Monitor B Call Tone Level
Choices are O, Low, Medium, and High
The Model 348 is capable of generating an audible
alerting signal when a call signal is detected on a
channel that is assigned to the Monitor B audio bus.
This signal consists of repeating sequences of three
short bursts of sine wave audio that are output by
way of the speaker. The level range can be selected
from among three choices as well as being selected
for o󰀨 (muted).
Remote Control Inputs – Overview
The Model 348 provides two contact closure inputs
that can be utilized in installer-implemented applica-
tions. They are physically located inside the Model
348’s enclosure on the main printed circuit board and
accessible using a 3-pin male “header” connector. A
technician will rst install a connector in the Model
348’s back panel and then make connections to
the header. Refer to the Technical Notes section for
details.
System – Remote Control Input 1
Choices are O, Talkback 1 Button, Talkback 2
Button, Talkback 3 Button, Talkback 4 Button,
Talkback 5 Button, Talkback 6 Button, Talkback 7
Button, and Talkback 8 Button
The action is performed when Remote Control Input 1
is enabled will follow the conguration selected from
among nine choices. When O is selected no action
will be associated with Remote Control Input 1. When
Talkback 1 Button, for example, is selected activating
Remote Control Input 1 will provide the same function
as pressing the Talkback 1 button. The precise action
of this remote control input function will be identical
to how the associated talkback button is congured.
Separate conguration choices allow the action of the
talkback buttons to be selected.
System – Remote Control Input 2
Choices are O, Talkback 1 Button, Talkback 2
Button, Talkback 3 Button, Talkback 4 Button,
Talkback 5 Button, Talkback 6 Button, Talkback 7
Button, and Talkback 8 Button
The conguration choices for Remote Control Input 2
are the same as those provided for Remote Control
Input 1.
Channel Specic Menu Page
The following conguration selections apply individ-
ually to Channels 1-8. They are available in each
Channel Specic menu tab:
Button Mode
Choices are Momentary, Latching, and Hybrid
The manner in which a button functions can be con-
gured from among three choices.
Momentary: If this mode is selected, a button’s func-
tion will normally be inactive and the LEDs associated
with the button will not be lit. Whenever a button is
pressed the associated function will become active
and its green LED will light.
Latching: If this mode is selected, the button’s
function will alternate between its active and inactive
states whenever the button is pressed. The button’s

Issue 8, July 2022 Model 348 User Guide
Page 16 Studio Technologies, Inc.
Model 348
INTERCOM STATION
green LED will be lit whenever the associated function
is active. Upon Model 348 power up the button will be
in its inactive state and its LEDs will not be lit.
Hybrid: This mode is a combination of the Momentary
and Latching modes. It’s similar to the way in which
pushbutton switches often function on user stations
associated with broadcast or production intercom
systems. If the button is pressed and held the asso-
ciated function will be active. It will stay active until
the button is released. If the button is momentarily
“tapped” the status of the function will change, either
from inactive-to-active or from active-to-inactive. The
button’s green LED will be lit whenever the function is
active. Upon Model 348 power up the button will be in
its inactive state and its LEDs will not be lit.
Button Function
Choices are Talk,Talk with 18 kHz Tone,All Talk,
Call,IFB,All IFB,18 kHz Tone,20 kHz Tone,
Talk with Quindar Tones, and Disabled
Talk: In this mode, whenever the function is active
microphone audio will be sent out the associated Dan-
te transmitter (output) channel. This mode will typically
be used as part of an intercom or stage announce
(SA) implementation. The sidetone function will be
active whenever the talk function is active.
Talk with 18 kHz Tone: This mode is similar to the
Talk mode except that an 18 kHz sine wave tone is
added (mixed or summed) with the microphone audio.
It is intended for use in REMI/At-Home applications
where a “pilot tone” needs to be sent along with talk
audio. This capability was specically provided for
use with the tone-activated (“TOX”) IFB function in
the Studio Technologies’ Model 5422A Dante Intercom
Audio Engine product or the IFB (talent cue) function
in the Models 232, 234, and 236 Announcer’s Con-
soles. The sidetone function will be active whenever
the Talk with 18 kHz Tone function is active.
All Talk: In this mode, the associated button will
activate all Model 348 channels that are congured
for Talk or Talk with 18 kHz Tone.
Call: In this mode, pressing the associated button
will cause a 20 kHz sine wave call tone to be sent
out any Model 348 channels that are both congured
for the Talk or the Talk with 18 kHz Tone modes and
are currently active.
IFB: In this mode, the Model 348 channel will be used
to create a broadcast-type IFB (interrupted foldback
or talent cue) source. When the function is not active
audio from the corresponding Dante receiver (input)
IFB program channel will be routed to the correspond-
ing Dante transmitter (output) channel. When the
function is active the microphone (interrupt) audio will
be combined (mixed or summed) with the IFB program
audio source. The IFB program audio source will be
attenuated, fully muted, or not changed, following the
IFB Program Dim conguration. The sidetone function
will be active whenever the IFB function is active.
All IFB: In this mode, pressing the associated but-
ton will cause all the channels congured for IFB to
become active. Note that an audio source routed to
the associated Dante receiver (input) IFB program
channel will be continually routed to the channel’s
associated Dante transmitter (output) channel. This
would typically be the non-interrupt audio source. This
is provided such that a timing match can be made
between the IFB and non-interrupt output channels.
18 kHz Tone: In this mode, an 18 kHz sine wave tone
will be sent out the associated Dante transmitter (out-
put) channel. This function can be useful for triggering
other functions associated with devices such as the
Model 5422A Dante Intercom Audio Engine.
20 kHz Tone: In this mode, a 20 kHz sine wave tone
will be sent out the associated Dante transmitter (out-
put) channel. This function can be useful for triggering
other functions associated with devices such as the
Model 5422A Dante Intercom Audio Engine.
Talk with Quindar Tones: In this mode, enabling the
talk function will cause a 2525 Hz sine-wave tone to
be added to the Dante transmitter (output) channel
for 250 mSec. This is called the intro tone. Then the
selected microphone source will be connected. Upon
the talk function no longer being active a sine-wave
tone of 2475 Hz will be sent out the Dante transmitter
(output) channel for 250 mSec. (This is called the
outro tone.)
Disabled: In this mode, the button will not perform a
function. Pressing it will cause the button’s red LED
to ash, indicating that it has been disabled.

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 17
Model 348
INTERCOM STATION
IFB Program Dim
Choices are 0 dB, 5 dB, 10 dB, 15 dB, 20 dB, and
Full Mute
This value determines the amount of attenuation that
will be applied to the Dante receiver (input) source
that is being used for program audio when the IFB
function is active for this channel. (The program audio
sources are IFB Pgm 1-7 and Aux In.) 0 dB will cong-
ure the channel to have no change in program audio
level. The talk audio will simply be added (mixed or
summed) with the program audio. When Full Mute is
selected the IFB program audio source level will fully
attenuate and be replaced by the talk (interrupt) audio.
In most broadcast applications the default value of
15 dB will be appropriate.
Headset Routing
Choices are O, Left, Right, and Left and Right
The Dante receiver (input) audio associated with a
Model 348 channel can be monitored using the head-
set’s headphone outputs. The destination channel(s)
can be congured as desired.
O󰀨: In this mode, the input audio will not be sent to
either the left or right headphone output channels.
Left: In this mode, the input audio will be sent to only
the left headphone output channel.
Right: In this mode, the input audio will be sent to
only the right headphone output channel.
Left and Right: In this mode, the input audio will
be sent to both the left and right headphone output
channels.
Monitor Routing
Choices are O, Monitor A, Monitor B, and Monitor
A and B
The Dante receiver (input) audio associated with a
Model 348 channel can be monitored using the Dante
monitor output channels. The destination channel(s)
can be congured as desired.
O󰀨: In this mode, the input audio will not be sent to
either of the monitor output channels.
Monitor A: In this mode, the input audio will be sent
only to the Monitor A output channel.
Monitor B: In this mode, the input audio will be sent
only to the Monitor B output channel.
Monitor A and B: In this mode, the input audio will be
sent to both the Monitor A and the Monitor B output
channels.
Listen Mode
Choices are Always and Channel 1 Active
This configuration choice selects under which
operating condition the audio source connected to
Dante receiver (input) channel 1 will be routed to the
headset’s headphone and monitor output channels.
This is a somewhat esoteric conguration but can
prove useful in specialized applications. Note that this
conguration will only apply to the specic channel
that is being congured, i.e., Channel 1, Channel 2,
Channel 3, etc.
Always: If this mode is selected, an audio source
connected to Dante receiver (input) channel 1 can
always be monitored using the headset’s headphone
and/or the monitor outputs. The state of the channel
1 function will not impact the ability to monitor this
source.
Channel 1 Active: In this mode, the source con-
nected to Dante receiver (input) channel 1can only
be monitored when the channel 1 function is active.
Call Indication
Choices are O, Visual Only, and Visual and Audible
A visual and audible indication can be provided when-
ever a call signal has been detected on a Model 348
input channel. The visual indication is provided by the
LED indicators associated with each rotary encoder.
The audible indication is provided by way of the Model
348’s internal loudspeaker and, if congured appro-
priately, Dante monitor outputs.
O󰀨: In this mode, no visual or audible indication in
response to a call signal will be generated.
Visual Only: In this mode, when a call signal is
detected in an input channel the LED in the associated
rotary encoder will ash orange.
Visual and Audible: In this mode, when a call signal
is detected the LEDs in the associated rotary encoder
will ash orange and sequences of audio tones will
be output by way of the monitor loudspeaker. The
audio tones will also be sent to the Monitor A and/or
Monitor B Dante transmitter (output) if the channel’s
audio input has been so congured.

Issue 8, July 2022 Model 348 User Guide
Page 18 Studio Technologies, Inc.
Model 348
INTERCOM STATION
Operation
At this point all connections and configuration
steps should have been completed and everything
should be ready for Model 348 operation to com-
mence. In most cases an Ethernet connection with
Power-over-Ethernet (PoE) capability will have been
made to the Primary Ethernet connector. Alternately,
a source of 12 volts DC may have been connected
to provide power for the Model 348. A stereo or mon-
aural headset will typically be interfaced using either
the Headset A or Headset B connector. A GME-3-12
gooseneck microphone may have been installed into
the bushing/connector assembly on the top of the
Model 348’s enclosure.
Using the Studio Technologies’ STcontroller software
application the Model 348’s operating conguration
should have been selected to meet the needs of the
specic application. An extensive range of congu-
rable parameters are available, making the way in
which a specic Model 348 operates be quite unique.
Using the Dante Controller software application the
Model 348’s network interface and audio channel
conguration should have been made. In this way, the
operational characteristics of the unit’s two Ethernet
interfaces will have been selected. In addition, some
or all of the eleven Dante transmitter (output) chan-
nels and sixteen Dante receiver (input) channels will
have been routed, by way of Dante “subscriptions,” to
the receiver and transmitter channels on associated
Dante-enabled equipment.
Eight of the Dante transmitter (output) channels are
associated with the functioning of the eight pushbutton
switches. Two additional Dante transmitter (output)
channels are specied as monitor outputs. And the
nal Dante transmitter (output) channel provides a Hot
Mic output function. Eight of the Dante receiver (input)
channels are assigned to the monitor section. Each
of these receivers (inputs) has an associated rotary
encoder to adjust its signal level. Seven more of the
Dante receiver (input) channels serve as IFB program
inputs. An eighth Dante receiver (input) channel, Aux
In, can serve as either an IFB program input or a
microphone source. These eight inputs are used in
conjunction with the eight pushbutton switches when
they are congured for IFB operation.
Initial Operation
The Model 348 will start to function as soon as a
Power-over-Ethernet (PoE) or a 12 volts DC power
source is connected. However, it may take up to 30
or 40 seconds for full operation to commence. Upon
initial power up the various status LEDs, located on
the back panel, and the mic source, rotary encoder,
and pushbutton LEDs on front panel will light as the
internal processors, Ethernet network, and Dante
connections begin to function. The various LEDs will
then become operational, displaying the status of their
associated functions.
Power Status LEDs
An LED labeled PoE is located below the Primary
Ethernet connector on the Model 348’s back panel.
It will light green if an Ethernet signal that is providing
PoE power is connected. An LED labeled DC is locat-
ed below the 4-pin XLR connector that is provided for
connection to a DC power source. It will light green
if a source of 10 to 18 volts DC is connected. If both
the PoE and DC LEDs are lit then the PoE Ethernet
connection will be providing power to operate the
Model 348. The DC power supply will be ready as a
“hot standby” should the PoE source fail.
Ethernet Status LEDs
A total of four Ethernet status LEDs are located below
the two etherCON RJ45 jacks on the Model 348’s
back panel. A LINK ACT LED will light green whenever
an active connection to an Ethernet network has been
established. It will ash in response to Ethernet data
packet activity on that interface. A GbE LED will light
orange when a Gigabit Ethernet connection is present
on that interface.
Dante Status LEDs
The SYS and SYNC LEDs, also located on the back
panel, display the operating status of the Dante inter-
face and its associated network activity. After lighting
red and green as part of the power-up sequence the
SYS LED will light red to indicate that the Dante inter-
face 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 also be part of the
power-up sequence and will light red when the Model
348 is not synchronized with a Dante network. It will
light solid green when the Model 348 is synchronized
with a Dante network and an external clock source
(timing reference) is being received. It will slowly

Model 348 User Guide Issue 8, July 2022
Studio Technologies, Inc. Page 19
Model 348
INTERCOM STATION
ash green when this specic Model 348 is part of a
Dante network and is serving as the Leader clock. It’s
possible that up to 30 or 40 seconds may be required
for the SYNC LED to reach its nal state.
How to Identify a Specic
Model 348
Functions within the Dante Controller and STcontroller
software applications allow specic Model 348 units to
be identied. Each application provides an “eyeball”
icon that when clicked will activate the Identify func-
tion. When Identify is selected it will send a command
to a specic Model 348 unit. On that unit the red LEDs
associated with the eight pushbutton switches will
“ash” in a unique sequence four times; the actual on/
o󰀨 status of the buttons will not change. In addition,
the LINK ACT and GbE status LEDs, located directly
below the two RJ45 jacks on the back panel, will
slowly ash. After a few seconds the LED identication
patterns will cease and normal Model 348 pushbutton
LED, and Ethernet status LED operation will resume.
Headset Microphone Power Status
LED
An LED indicator is located on the back panel adjacent
to the Headset A connector. It is labeled MIC PWR
and will light red whenever the headset’s microphone
electret power source is active and providing low-
voltage DC power to the microphone connections on
the Headset A and Headset B connectors.
Compressor Active LED and Mic
Preamp Gain
An LED indicator, orange in color, is located on the
back panel adjacent to the Headset A connector.
It is labeled COMP and displays the status of the
microphone audio compressor function. This func-
tion controls the dynamic range of the audio signal
associated with either the headset’s microphone or
the gooseneck microphone. The compressor active
LED will light whenever the input level from either
the headset mic or the gooseneck mic, along with
the congured microphone preamplier gain, is such
that the dynamic range of the signal is being actively
controlled. It’s perfectly acceptable for this LED to
light intermittently whenever a user is talking at a
normal voice level into an associated microphone. But
if the COMP LED lights solid while a user is talking
at a normal voice level this will typically indicate that
the microphone preamplier gain setting should be
reduced. Conversely, if the COMP LED almost never
lights when normal talking is taking place it’s possible
that changing the gain to a higher value would be
benecial. Note that if the Dante Aux In channel has
been selected as the microphone source the COMP
LED will never light.
LED Intensity
On the Model 348’s front panel there are LED indi-
cators associated with the eight channel pushbutton
switches, the mic source status display, and the ten
rotary encoders. Using the STcontroller software ap-
plication the intensity of these LEDs, as a group, can
be congured from among two choices, low or high.
If during operation the LED intensity isn’t perceived
to be optimal the conguration choice in STcontroller
should be checked and revised if necessary. In most
cases the default intensity, high, will be applicable.
However, the low LED intensity conguration choice
may be superior in applications where the ambient
light in the Model 348’s location is also low.
Mic Source Selection
A small, round pushbutton switch located on the
upper-left side of the front panel is used to select
which microphone source is active. Pressing the
button will change the source to the next available
one. The selected audio source will be used by the
Model 348’s talk, sidetone, and IFB functions. The
mic source choices are Headset, Gooseneck, and
Aux In. Two green LEDs, adjacent to the pushbutton
switch, indicate which microphone source is currently
active. When the LED marked HEADSET is lit the
microphone associated with a connected headset is
serving as the Model 348’s microphone (talk) audio
source. When the LED marked GOOSENECK is lit
the gooseneck microphone will serve as the talk au-
dio source. When neither LED is lit the Dante Aux In
receiver (input) channel will be serving as the talk
audio source. A Model 348 power-down/power-up
cycle will return the microphone source to its last
selection.
A system conguration choice in STcontroller is used
to select whether or not the Dante Aux In receiver
(input) channel can serve as a microphone source.
By default the choice is O󰀨 and the Aux In will not
be able to be selected. In this case, the pushbutton

Issue 8, July 2022 Model 348 User Guide
Page 20 Studio Technologies, Inc.
Model 348
INTERCOM STATION
switch will alternate between the headset mic and the
gooseneck mic.
Another STcontroller conguration allows the micro-
phone source selection to impact the on/o󰀨 status
of the headset’s headphone output and the moni-
tor output channels. Named Headset and Monitor
Outputs Follow Mic Source, this selection is provided
to assist users who frequently change between using
the headset’s microphone, gooseneck microphone,
and/or the Aux In channel. The default conguration
is for this feature to be disabled (O󰀨). When this con-
guration choice is enabled (On) and Gooseneck or
Aux In is selected as the microphone source the
headset’s headphone outputs will mute. When the
headset’s microphone is selected as the source the
monitor outputs and associated loudspeaker will also
mute. In both cases the mute state that was automati-
cally enabled can be overridden by pressing the knob
on the applicable rotary encoder.
The headset and gooseneck microphone inputs
have an independent preamplifier gain configura-
tion parameter which is accessible by way of the
STcontroller software application. And the Aux In
channel has a configuration gain trim function. If
switching between the three sources results in greatly
di󰀨erent overall talk audio levels then the conguration
choice for the headset and gooseneck microphone
preamplifier gain and Aux In level trim should be
reviewed and revised as appropriate.
Hot Mic Output
A Dante transmitter (output) channel has been desig-
nated as a hot mic output. This output can be enabled
or disabled using the STcontroller software applica-
tion. The default setting is Disabled. When enabled
the selected microphone source – headset, goose-
neck, or Aux In – will connect to the Hot Mic Dante
transmitter (output) channel. No pushbutton or rotary
encoder operation is required for the audio associated
with the selected microphone source to be active on
the Hot Mic Dante transmitter (output). This can be a
useful feature but it’s important that user’s be made
aware that there is no means of turning o󰀨 (“muting”)
this output. They must assume that other personnel
will be continually monitoring audio associated with
their selected talk source.
Button Action
The action of each of the eight pushbutton switches
can be individually configured using STcontroller.
There are three button action choices available and
a description of them follows:
Momentary
If this mode is selected, the pushbutton’s associated
function will become active whenever the button is
pressed and held. When the function is active the
pushbutton’s green LEDs will be lit.
Latching
If this mode is selected, the function associated with
the button will alternate between its active and inac-
tive states whenever the pushbutton is momentarily
pressed (“tapped”). The pushbutton’s green LEDs will
be lit whenever the function is active. Upon Model 348
power up the button’s associated function will be in
its inactive state.
Hybrid
This mode is a combination of the momentary and
latching actions. If the pushbutton is pressed and
held the associated function will become active until
the pushbutton is released. If the pushbutton is mo-
mentarily pressed (“tapped”) the function will change
state. The pushbutton’s green LEDs will be lit when-
ever the function is active. Upon Model 348 power
up the pushbutton’s associated function will be in its
inactive state.
Button Function
The button function conguration is used to select the
overall manner in which a specic pushbutton channel
operates. Each pushbutton can be independently
congured from among ten choices. A careful study
of how each of these choice’s function will highlight
the variety of applications a Model 348 can support.
While the product’s title includes the text “Intercom
Station,” that far from covers all the applications in
which the unit can provide value.
Talk
When a button function has been congured for Talk
and the pushbutton is pressed or the function is active
then audio from the selected microphone source will
be connected to the associated Dante transmitter
(output) channel. The LED in the pushbutton switch
will light green whenever the function is active. When
the pushbutton is not pressed nor currently active no