Studio Technologies 348 User manual

Copyright © 2020 by Studio Technologies, Inc., all rights reserved
www.studio-tech.com
User Guide
Issue 1, January 2020
This User Guide is applicable for serial numbers
M348-00151 and later with main firmware version 1.05 and later
and STcontroller application version 2.06.00 and later.
50291-0120 Issue 1
Model 348 Intercom Station

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Model 348 User Guide Issue 1, January 2020
Studio Technologies, Inc. Page 3
MODEL 348
INTERCOM STATION
Table of Contents
Revision History ........................................................... 4
Introduction .................................................................... 5
Getting Started .............................................................. 7
Dante Configuration ...................................................... 11
Model 348 Configuration .............................................. 12
Operation ...................................................................... 19
Technical Notes ............................................................ 28
Specifications ............................................................... 33
Appendix A ................................................................... 35

Issue 1, January 2020 Model 348 User Guide
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MODEL 348
INTERCOM STATION
Revision History
Issue 1:
• Initial release of complete document.

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MODEL 348
INTERCOM STATION
Introduction
The Model 348 Intercom Station provides
eight independent talk and listen channels
that are compatible with Dante® audio-over-
Ethernet networks. The desktop unit is de-
signed to serve as an audio control center for
production and support personnel in numer-
ous applications including on-air television
sports and news broadcasting, live events,
theater, industrial, 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 applications may benefit from
the Model 348 user’s ability to easily cre-
ate 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) in-
tercom applications with help from an ex-
ternal Dante-enabled audio matrix such as
the Studio Technologies’ Model 5422 Dante
Intercom Audio Engine. Model 348 units can
also be used “point-to-point” or interfaced with
Dante-compatible matrix intercom systems.
The Model 348 includes two Neutrik ether-
CON RJ45 connectors which allow interfac-
ing with single or redundant Gigabit Ethernet
networks. The primary network connection
can provide power to the unit using a port on
a Power-over-Ethernet (PoE) network switch.
It can also be powered using a 12 Volt DC
source that is connected using a broadcast-
standard 4-pin XLR connector.
The Model 348 allows connection of broad-
cast- or intercom-style headsets that use
a dynamic or electret (DC powered) micro-
phone. The unit provides both 5-pin female
XLR and 3.5 mm TRRS connectors which
allow both traditional “pro” and contemporary
gaming headsets to be utilized. In addition,
the Studio Technologies’ GME-3-12 electret
gooseneck microphone can be directly con-
nected using the ¼-inch jack located on the
top of the unit’s enclosure. A pushbutton
switch allows users to directly select headset
or gooseneck microphone operation. A low-
noise microphone preamplifier and associated
voltage-controlled-amplifier (VCA) dynamics
controller (compressor) ensures excellent
microphone audio quality while minimizing the
chance of signal overload.
Figure 1. Model 348 Intercom Station front and back views

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MODEL 348
INTERCOM STATION
All Model 348 operating features are config-
ured using the STcontroller software applica-
tion. The extensive set of parameters allows
the unit’s functions to be tailored to meet the
needs of many applications. STcontroller,
compatible with version 7 and later of the
Windows® operating system, is available,
free of charge, from the Studio Technologies’
website. It’s a fast and simple means of con-
figuring, 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, each control is illuminated and
can display if signal is present on the associ-
ated audio channel or if the channel is muted.
The user can monitor the Dante audio inputs
by means of either the headset or a built-in
speaker. A modern class-D amplifier integrated
circuit drives the speaker efficiently while
preserving audio fidelity. Two additional rotary
encoders are used to control the master audio
level and mute (on/off) status of the signals be-
ing sent to the headset and speaker outputs.
Extensive configuration choices allow the
operation of the eight pushbutton switches
and associated output channels to be opti-
mized to meet the needs of specific applica-
tions. They can be independently configured
for talk (intercom), IFB (talent cueing), call
signal (20 kHz tone), and other related actions.
The buttons can also be configured to provide
“all-call” functions associated with talk and IFB
functions.
The Model 348’s pushbutton switches are
illuminated to display their operating status as
well as having the ability to indicate the pres-
ence of in-band (20 kHz tone) call signals. An
audible alert, using the internal speaker, can
also be generated in response to a call signal.
For performance confirmation an integrated
sidetone function allows audio coming from
the headset’s microphone to be returned to the
headset output.
The Model 348’s compact enclosure has over-
all dimensions of 6.5 inches wide (16.5 cm),
2.5 inches high (6.4 cm), and 4.6 inches deep
(11.7 cm). Weighing 1.8 pounds (0.8 kg), the
enclosure is made of steel to provide some
“heft” to minimize the chance of inadvertent
movement. The Model 348’s main application
firmware can be updated using the USB port
on the back of the unit; the Dante firmware 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 Gigabit
(“GigE”) twisted-pair Ethernet interfaces. The
1000BASE-T interconnections are made by
way of Neutrik® etherCON RJ45 connectors.
While compatible with standard RJ45 plugs,
etherCON allows a ruggedized and locking
interconnection for harsh or high-reliability
environments. The two Ethernet interfaces
can be configured, using the Dante Controller
software applications, to serve in a switched
or redundant mode.
The Model 348’s operating power can be pro-
vided by way of the Primary Ethernet interface
using the 802.3af Power-over-Ethernet (PoE)
standard. PoE allows fast and efficient inter-
connection 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-Ether-
net media networking technology. As a Dante-
compliant device, the Model 348’s 11 Dante
transmitter (audio output) channels and 16

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MODEL 348
INTERCOM STATION
Dante receiver (audio input) channels can
be assigned (routed or “subscribed”) using
the Dante Controller software application.
The Dante transmitter and receiver channels
support 32 Dante flows, 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, provide status indi-
cations of the Ethernet network and Dante
interface performance.
The Model 348 is compliant with the AES67
interoperability 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 com-
pletely “pro.” A low-noise, wide dynamic-range
microphone preamplifier and associated
voltage-controlled-amplifier (VCA) dynamics
controller (compressor) ensure that headset
and gooseneck microphone audio quality is
preserved and minimizes the chance of sig-
nal 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. The
audio signal, now in the digital domain, routes
through a 32-bit microprocessor and on to the
Dante interface section where it is packetized
and prepared for transport over Ethernet. A
total of 11 Dante transmitter (output) chan-
nels 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 re-
ceiver channels and pass into the Model
348’s 32-bit microprocessor. Eight channels
are associated with the monitor section while
the other eight are used as program sources
for the IFB (talent cue) functions. All channel
routing, headphone and monitor level con-
trol, IFB creation, and sidetone functions are
performed within the digital domain. This pro-
vides flexibility, allows precise level control,
eliminating the need for analog audio signals
from having to pass through the level controls.
The audio signals destined for the headphone
outputs are sent to a high-performance digi-
tal-to-analog converter 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 firmware (embedded software)
to be updated using a USB flash drive. The
Model 348 uses the Broadway™ integrated
circuit from Audinate to implement the Dante
interface. The firmware in this integrated
circuit can be updated via an Ethernet con-
nection, 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 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 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

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MODEL 348
INTERCOM STATION
addition, it’s possible that a gooseneck
microphone will be attached via the ¼-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 RJ45 connector is compatible
with Power-over-Ethernet (PoE). If desired,
an Ethernet connection made to the second-
ary Ethernet connector can provide access
to a redundant Dante network. Or it can be
utilized as an active “loop through” connection
associated with the primary Ethernet connec-
tion. 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 ¼-inch plug can be connected.
One or Two Ethernet Connections
One 1000BASE-T (“GigE”) Ethernet connec-
tion is required for Model 348 operation. If
available and connected to the primary RJ45
connector, this connection can provide both
the Ethernet data interface and power for the
Model 348’s circuitry. A 10BASE-T connection
is not sufficient. A 100BASE-TX connection
may be adequate but not optimal.
A second 1000BASE-T (“GigE”) connection
can be made if redundant Dante is desired.
The Model 348’s network configuration must
be set for redundant for this functionality to be
active. PoE is not supported on the secondary
Ethernet connection. The secondary Ethernet
port can also be used as a “loop through” port
such as would be provided by an Ethernet
switch. This requires that the Model 348’s
network configuration is set for switched.
Switched mode is the default setting but using
the secondary port in this mode for applica-
tions other than troubleshooting is not rec-
ommended. It will function reliably but “daisy
chaining” Ethernet signals can limit flexibility
and present a failure point.
The Ethernet connections are made by way
of two Neutrik etherCON protected RJ45
connectors that are located on the back of
the Model 348’s enclosure. These allow con-
nection by way of cable-mounted etherCON
connectors or standard RJ45 plugs. The
Model 348’s Ethernet interface supports auto
MDI/MDI-X so that a crossover cable is not
required. The Model 348’s primary Ethernet
connection does not enumerate itself as a
specific PoE class. As such, a PoE power-
sourcing-equipment (PSE) port will consider
the device as a class 0 device which could
use 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 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 volt
range. The Model 348 requires a maximum
of 600 milliamperes (0.6 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 op-
tion from Studio Technologies, is directly com-
patible 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.

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MODEL 348
INTERCOM STATION
As previously discussed in this guide, an
Ethernet connection that provides power-
over-Ethernet (PoE) can serve as the Model
348’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 348’s power. No interruption
in operation will occur during a power source
transition.
Headset Connections
The Model 348 allows two different types of
headsets to be connected. A 5-pin female
XLR connector, located on the Model 348’s
back panel, allows connection of a standard
broadcast- or intercom-style communica-
tions headset. A 3.5 mm 4-conductor TRRS
jack, also located on the back panel, allows a
computer gaming headset to be directly con-
nected. The Model 348’s two headset connec-
tors 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
connector that interfaces with the microphone
and headphone 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 mi-
crophone 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 phan-
tom power.
To allow users of stereo (dual-earpiece or
“double-muff”) 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 headphone channel to
pin 5. Software-based configuration choices,
discussed later in this guide, can be used to
create the desired monaural output. It’s impor-
tant 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-muff”)
headset should be wired such that its head-
phone is wired only to pin 4; pin 5 should
be remain unused. Configuration choices,
discussed later in this guide, can be used
to create a monaural output.
It’s possible that some Beyerdynamic headset
interconnecting cable assemblies terminate
the earpiece’s left and right connections op-
posite 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 ear-
piece to pin 4. If this condition is present it will
require reversing or “flipping” the two wires in
a headset’s connector such that the left ear-
piece connects to pin 4 and the right earpiece
to pin 5.
Figure 2. Headset A connection pinout chart

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INTERCOM STATION
If a separate microphone and pair of stereo or
monaural headphones need to be connected
an adapter cable assembly must be fabri-
cated. It would consist of a 5-pin male XLR
connector wired to both a 3-pin female XLR
connector for the microphone and a ¼-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” microphones are dynamic and should
function correctly.
Headset B
The Model 348 also allows direct connec-
tion 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 configuration
standard which has the headphone left chan-
nel 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 head-
sets are readily available, typically described
as personal computer or gaming headsets.
The microphones used in these headsets are
electret 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 person-
al computer software application be selected.
Refer to Figure 3 for a detailed description of
the compatible TRRS plug.
Gooseneck Microphone
A threaded combination bushing/3-conductor
1/4-inch jack is incorporated into the top panel
of the unit. This allows direct connection of the
Studio Technologies’ GME-3-12 Gooseneck
Microphone. This unidirectional, electret micro-
phone was designed specifically to maximize
performance in intercom and related applica-
tions. 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 ¼-inch 3-conductor plug with inte-
grated threads that have a pitch 7/16-20 UNF.
The 3-conductor ¼-inch jack associated with
the Model 348’s 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. 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 micro-
phone may need to be removed and stored
for transit. In this case the set screw should
be removed and stored.
Figure 3. Headset B (TRRS) connection pinout chart

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MODEL 348
INTERCOM STATION
Dante Configuration
For audio to correctly pass to and from the
Model 348 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 348’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
Controller are available to support Windows
and OS X® operating systems. The Model 348
uses the Broadway integrated circuit to imple-
ment 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 (Tx)
channels must be assigned to the desired
receiver 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 transmitter flow
(a group of output channels) to a receiver
flow (a group of input channels).
The number of transmitter flows associated
with a Broadway integrated circuit and, as
such the Model 348, is 16 so no limitation can
exist. These flows can either be unicast, mul-
ticast, 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 16 receiver
(Rx) channels associated with the Model 348’s
Dante audio inputs. The exact number utilized
will depend on the specific application. The
first eight receiver channels are automatically
assigned to the level encoders and can be
used for listening to the associated intercom
channels or as general-purpose audio channel
monitoring. The second set of eight receiver
channels are associated with the IFB (talent
cueing) functions. They will be utilized only with
channels that have their IFB function enabled.
Unit and Channel Names
The Model 348 has a default Dante device
name of ST-M348- along with a unique suf-
fix. The suffix identifies the specific Model 348
that is being configured. The suffix’s actual
alpha and/or numeric characters relate to the
MAC address of the unit’s Broadway integrated
circuit. The 16 Dante receiver (Rx) audio input
channels have default names of Ch 1 – Ch 8
and IFB Pgm 1 – IFB Pgm 8. The 11 Dante
transmitter (Tx) audio output channels have
default names of Ch 1 – Ch 8, Mon A, Mon B,
and Hot Mic. Using Dante Controller the de-
fault device name and channel names can
be revised as appropriate for the specific
application.
Device Configuration
The Model 348 only supports an audio sample
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 appro-
priate. Clocking and Device Latency can be
adjusted if required but the default values are
typically correct.
Network Configuration – Dante Redundancy
The Model 348 allows connection of two Ether-
net 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.

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INTERCOM STATION
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 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 348’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 348’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 re-
dundant networking implementation will be
enabled. In this case, separate network con-
nections should be made to the Primary-PoE
and Secondary RJ45 connectors. A personal
computer that’s running STcontroller will typi-
cally 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 ad-
dress will be associated with the network con-
nection that is made to either the Primary-PoE
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 348’s Dante IP address
and related network parameters will be deter-
mined 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 ca-
pability 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 specific static IP ad-
dress. 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 configura-
tion has been set for Redundant then the Pri-
mary and Secondary Dante IP addresses and
related parameters can be independently con-
figured. This allows both to be automatic, both
to be manually configured, or one to be auto-
matic and the other to be manually configured.
AES67 Configuration – AES67 Mode
The Model 348 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 348 Clocking Source
While technically the Model 348 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
348 would not be enabled.
Model 348 Configuration
The STcontroller software application is used
to configure the way in which the Model 348
functions. No DIP switch settings or other lo-
cal actions are used to configure the unit. This
makes it imperative that STcontroller be avail-
able for convenient use on a personal computer
that’s connected to the related LAN.

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Installing STcontroller
STcontroller is available free of charge on the
Studio Technologies’ website (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
348. If required, download and install STcon-
troller 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 configured. Im-
mediately after starting STcontroller the appli-
cation will locate all the Studio Technologies’
devices that it can control. The one or more
Model 348 units to be configured will appear
in the device list. Use the Identify command
to allow easy recognition of a specific Model
348 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.
Parameters
The configurable functions include:
General menu page:
• Microphone Input – Headset Mic Power
• Microphone Input – Headset Mic Gain
• Microphone Input – Gooseneck Mic Gain
• Headset – Sidetone Level
• Headset – Dim
• Speaker – Source
• Speaker – Dim
• Dante Monitor Outputs – Mode
• Dante Monitor Outputs – Dim
• System – Level Control Position Display
• System – Signal Present Display
• System – LED Intensity
• System – Headset and Monitor Outputs
Follow Mic Source
• System – Hot Mic
• System – Monitor A Call Tone Level
• System – Monitor B Call Tone Level
Channel Specific menu page (independent
configuration settings for channels 1-8):
• Button Mode
• Button Function
• IFB Program Dim
• Headset Routing
• Monitor Routing
• Call Indication
Changes made using STcontroller will be
immediately reflected in the unit’s operation;
no Model 348 reboot is required. Each time
a change is made the eight buttons on the
Model 348’s front panel will flash orange in a
distinctive pattern to indicate that a command
from STcontroller has been received.
General Menu Page
The following configuration selections are
available in the General menu selections tab:
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 Head-
set A, or a 3.5 mm 4-conductor TRRS jack,
labeled Headset B. Enable the headset mi-
crophone power check box if the connected
headset has an electret microphone which
requires a source of low-voltage DC for opera-
tion. In virtually all cases gaming or computer
headsets that use a 3.5 mm TRRS plug will
require microphone power. Most broadcast

Issue 1, January 2020 Model 348 User Guide
Page 14 Studio Technologies, Inc.
MODEL 348
INTERCOM STATION
headsets that terminate on a 5-pin male XLR
connector will incorporate a dynamic (non-
powered) microphone. In this case do not en-
able headset microphone power. The on/off
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
associated with a headset, the gain of the
microphone preamplifier can be selected from
among five choices. The selected gain is ap-
plied no matter if the headset is connected
using the Headset A or the Headset B connec-
tor. The compressor active LED, located below
the Headset A connector, can act as a guide
when setting the microphone preamplifier gain.
When a voice signal at a normal level is pres-
ent on the connected headset’s microphone
the compressor active LED should light inter-
mittently. 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
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 otherwise 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 active microphone input
source the gain of the microphone preampli-
fier will operate from among five configurable
choices. The compressor active LED, located
adjacent to the Headset A connector, can act
as a guide when setting the gooseneck pre-
amp gain. When a voice signal at a normal
level is presented to the gooseneck micro-
phone 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 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.
Headset – Sidetone Level
Choices are Off, Low, Medium Low, Medium,
Medium High, and High.
As a user confidence signal, audio from the
selected microphone source can be routed
to the left and right headphone channels of
the headset interface. Sidetone audio can be
present whenever an applicable button func-
tion is active on any or all of the unit’s eight
channels. An applicable function is one that
uses either the headset or the gooseneck
microphone. These include Talk, Talk with
18 kHz Tone, and IFB. There is no definitive
sidetone level setting. One that provides the
user with a sufficient amount of their own talk
audio such that they are comfortable should
be sufficient.
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

Model 348 User Guide Issue 1, January 2020
Studio Technologies, Inc. Page 15
MODEL 348
INTERCOM STATION
“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 amplifier or set
of amplified speakers. Normally when a talk
function is active on one or a combination
of the eight channels the level of the head-
set’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 head-
phone output channels 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 se-
lecting a dim configuration of 6, 12, or 18 dB
might be desirable.
Speaker – Source
Choices are Off, Monitor A, and Monitor B.
The Model 348 includes an internal loud-
speaker of which an audio source can be se-
lected from the two audio “mix” buses that are
named Monitor A or Monitor B. These buses
contain audio content that is specified in the
individual configuration 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
loudspeaker 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. In-
terference 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 pro-
vides more reduction. In almost all cases a
selection of other than 0 dB (no dim) would
be appropriate.
Dante Monitor Outputs – Mode
Choices are Off, Pre-Fader, and Post-Fader.
The Model 348 provides two Dante transmit-
ter (output) channels, Monitor A and Monitor
B, that are intended for use by other pieces
of equipment such as amplified speakers,
audio consoles, and matrix intercom systems.
These two channels can be configured 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 in-
dicate 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/off status of Dante monitor output channels
will not be impacted by the Model 348’s moni-
tor output rotary encoder. To clarify, neither
level adjustment or on/off 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/off status of Dante output channels Moni-
tor A and Monitor B will follow the action of
the Model 348’s monitor output rotary en-
coder. 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.

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MODEL 348
INTERCOM STATION
Dante Monitor Outputs – Dim
Choices are 0 dB, 6 dB, 12 dB, and 18 dB.
When a talk or IFB function is active the Mod-
el 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 Off and On.
For user assistance the orange LEDs con-
tained within the eight pushbutton switches
can be utilized in a “bar graph” format to give
a general indication of the settings of the ten
rotary encoders. If enabled, whenever the set-
ting 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 Off and On.
The top surface of the ten rotary encoders
can light as an indication of the level of the
audio associated with a specific encoder and
related function. This is accomplished by the
incorporation of red, green, and blue LEDs
located within each 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 sig-
nal level is at risk of degrading audio perfor-
mance. Note that even if the Signal Present
Display function is disabled (Off) 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 en-
coders, and mic source selection function have
LED indicators associated with them. The
LED intensity configuration choice allows the
overall intensity of theses 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 Off 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 and the gooseneck microphone.
When the function is enabled, whenever the
microphone source selection changes from
gooseneck to headset the Dante monitor
output channels (only when configured for
post-fader) and the speaker will mute. And
whenever the microphone source selection
changes from headset to gooseneck the head-
set’s headphone outputs will mute. This helps
to ensure that unwanted audio isn’t present as
a specific microphone source is selected.
System – Hot Mic
Choices are Off and On.
A Dante transmitter (output) channel is avail-
able which provides a hot mic (always active)
function. This can be very useful but has the
potential for abuse. This configuration choice
ensures that a hot mic signal is only available
when an application warrants it.

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MODEL 348
INTERCOM STATION
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 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 associated
function will be active. It will stay active until
the button is released. If the button is momen-
tarily “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, and Disabled.
Talk: In this mode whenever the function is
active microphone audio will be sent out the
associated Dante audio output (transmitter)
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 (summed) with the micro-
phone audio. It is intended for use in REMI/
At-Home applications where a “pilot tone”
needs to be sent along with talk audio. This
is specifically provided for use with the tone-
activated (“TOX”) IFB function in the Studio
Technologies’ Model 5422 Dante Intercom
Audio Engine product. The sidetone function
Note that even if the hot mic output is disabled
the channel will appear in the Dante Controller.
But in this case no signal would be present on
the channel.
System – Monitor A Call Tone Level
Choices are Off, 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 off (muted).
System – Monitor B Call Tone Level
Choices are Off, 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 off (muted).
Channel Specific Menu Page
The following configuration selections apply
individually to Channels 1-8. They are available
in each Channel Specific menu tab:
Button Mode
Choices are Momentary, Latching, and Hybrid.
The manner in which a button functions can be
configured from among three choices.
Momentary: If this mode is selected a button’s
function will normally be inactive and the LEDs
associated with the button will not be lit. When-
ever a button is pressed the associated function
will become active and its green LED will light.

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MODEL 348
INTERCOM STATION
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
configured 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 configured 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 inter-
rupted foldback (IFB) or talent cue source.
When the function is not active audio from the
corresponding Dante IFB program audio input
channel will be routed to the corresponding
Dante output channel. When the function is
active the microphone (interrupt) audio will be
combined with the IFB program audio source.
The IFB program audio source will be attenu-
ated, fully muted, or not changed, following
the IFB Program Dim Level configuration. The
sidetone function will be active whenever the
IFB function is active
All IFB: In this mode pressing the associated
button will cause all the channels configured
for IFB to become active. Note that an audio
source routed to the associated IFB pro-
gram input will be continually routed to the
channel’s associated audio output. 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 output (transmitter) channel. This func-
tion can be useful for triggering other func-
tions associated with devices such as the
Model 5422 Dante Intercom Audio Engine.
20 kHz Tone: In this mode a 20 kHz sine
wave tone will be sent out the associated
Dante output (transmitter) channel. This func-
tion can be useful for triggering other func-
tions associated with devices such as the
Model 5422 Dante Intercom Audio Engine.
Disabled: In this mode the button will not
perform a function. Pressing it will cause the
button’s red LED to flash, indicating that it has
been disabled.
IFB Program Dim
Choices are 0 dB, 5 dB, 10 dB, 15 dB, 20 dB,
and Full Mute.
This value determines the amount of attenua-
tion that will be applied to the Dante program
audio input (receive) source when the IFB
function is active for this channel. 0 dB will
configure the channel to have no change in
program audio level. The talk audio will simply
be added (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 Off, Left, Right, and Left and
Right.
The Dante input (receiver) audio associated
with a Model 348 channel can be monitored
using the headset’s headphone outputs. The
destination channel(s) can be configured as
desired.
Off: In this mode the input audio will not be
sent to either the left or right headphone out-
put 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.

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MODEL 348
INTERCOM STATION
associated pushbutton will flash on and off.
In addition, sequences of audio tones will be
output by the monitor loudspeaker. The audio
tones will also be sent to the Monitor A and/or
Monitor B Dante output if the channel’s audio
input has been so configured.
Operation
At this point all connections and configuration
steps should have been completed and every-
thing should be ready for Model 348 opera-
tion to commence. 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 monau-
ral headset will typically be interfaced using
either the Headset A or Headset B connec-
tor. A 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 operat-
ing configuration should have been selected
to meet the needs of the specific application.
An extensive range of configurable param-
eters are available, making the way in which a
specific Model 348 operates be quite unique.
Using the Dante Controller software applica-
tion the Model 348’s network interface and
audio channel configuration should have been
made. In this way, the operational charac-
teristics of the unit’s two Ethernet interfaces
will have been selected. In addition, some or
all of the eleven Dante audio output chan-
nels (Dante transmitter channels) and sixteen
Dante audio input channels (Dante receiver
channels) will have been routed, by way of
Dante “subscriptions,” to the receiver and
transmitter channels on associated Dante-
enabled equipment.
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 Off, Monitor A, Monitor B, and
Monitor A and B.
The Dante input (receiver) audio associated
with a Model 348 channel can be monitored
using the Dante monitor output channels. The
destination channel(s) can be configured as
desired.
Off: 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.
Call Indication
Choices are Off, Visual Only, and Visual and
Audible.
A visual and audible indication can be provid-
ed whenever a call signal has been detected
on a Model 348 channel. The visual indication
is provided by way of the pushbutton’s LED in-
dicators. The audible indication is provided by
way of the Model 348’s internal loudspeaker
and, if configured appropriately, Dante monitor
outputs.
Off: 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 the orange LED in the associated
pushbutton will flash on and off.
Visual and Audible: In this mode when a
call signal is detected the orange LED in the

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MODEL 348
INTERCOM STATION
Ethernet Status LEDs
A total of four Ethernet status LEDs are locat-
ed below the two etherCON RJ45 connectors
on the Model 348’s back panel. A LINK ACT
LED will light green whenever an active con-
nection to an Ethernet network has been es-
tablished. It will flash 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 interface 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
interface is not ready. After a short interval it
will light green to indicate that it is ready to
pass data with another Dante device. The
SYNC LED will 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 flash green when
this specific Model 348 is part of a Dante net-
work and is serving as the clock master. It’s
possible that up to 30 or 40 seconds may be
required for the SYNC LED to reach its final
state.
How to Identify a Specific
Model 348
Functions within the Dante Controller and
STcontroller software applications allow spe-
cific Model 348 units to be identified. Each
application provides an “eyeball” icon that
when clicked will activate the Identify function.
When Identify is selected it will send a com-
mand to a specific Model 348 unit. On that
unit the red LEDs associated with the eight
Eight of the Dante audio output channels are
associated with the functioning of the eight
pushbutton switches. Two additional Dante
audio output channels are specified as moni-
tor outputs. And the final Dante output chan-
nel provides a Hot Mic output function. Eight
of the Dante audio input channels are as-
signed to the monitor section. Each of these
inputs has an associated rotary encoder to
adjust its signal level. Eight more of the Dante
audio input channels serve as IFB program
inputs. These are used in conjunction with
the eight pushbutton switches when they are
configured 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 op-
eration to commence. Upon initial power
up the various status LEDs, located on the
back panel, and the mic source, rotary en-
coder, 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 as-
sociated functions.
Power Status LEDs
An LED labeled PoE is located below the pri-
mary Ethernet connector on the Model 348’s
back panel. It will light green if an Ethernet
signal that is providing PoE power is con-
nected. An LED labeled DC is located 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 con-
nected. 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.