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Highlights
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Excellent audio quality
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Configuration flexibility
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Simple user interface
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Advanced intercom interface
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Next-generation performance
Overview
The
Model 230 Announcer’s Console is designed to serve as the audio control
“hub” for announcers, commentators, and production personnel. The
tabletop unit is suited for numerous applications including on-air
television and radio broadcasting. The Model 230 is compatible with
essentially all broadcast and production audio system environments.
Standard connectors are used to interface microphone, headphone, on-air,
talkback, IFB, and intercom signals.
Whether it’s the mic
preamplifier, audio switching, talkback signals, intercom interfacing,
or headphone cue feed, superior audio quality is maintained throughout.
A microprocessor provides the Model 230’s logic power, allowing precise
control of the unit’s operation. With extensive flexibility built in,
creating the desired operating configuration is a simple matter. While
the operating features of the unit can be extensively configured, the
user is presented with an easy-to-use set of controls and indicators. A
wide range of resources, great performance, and simplicity during
use—these are the hallmarks of the Model 230.
A truly next-generation
product, extensive research into the needs and desires of field
production personnel was integral to the Model 230’s creation. Providing
a veritable “tool kit” of features, the unit supports a wide variety of
applications that include on-air television and radio broadcasting,
stadium announcement, and simultaneous interpretation. In addition, with
the unit’s broad range of capabilities many other specialized
“behind-the-scenes” applications can also be implemented.
Microphone
Input
A high-performance microphone
preamplifier circuit provides low-noise/low-distortion amplification
over a 20 to 60 dB gain range. The gain is adjustable in 10 dB steps. The
input is compatible with balanced dynamic and condenser microphones. The
microphone power source is 48 volts nominal and meets the worldwide P48
phantom standard. An LED indicator serves as an aid for optimizing the
preamplifier’s gain setting. The output of the microphone preamplifier
is used by the main output as well as being routed to the compressor
circuit that supports the talkback functions.
Main
Output
The Model 230 provides a main output
that is designed to serve as the on-air, stadium announcement, or other
primary audio feed. Nominally –2 dBu, it is designed as a fully
professional interface with high output capability, low distortion, and
low noise. The output circuitry features a high-performance output
transformer expressly designed for professional audio applications.
For specialized applications an optional
direct microphone output card is available. This allows an external
microphone preamplifier to be used. Of course this output also provides
“click-free” microphone on/off (“muting”) control.
Talkback Functions
The talkback functions are intended to
provide personnel associated with production trucks, control rooms,
live-performance, and sports venues with talent-originated cue signals.
The Model 230 contains two pushbutton switches that control the talkback
functions. Each button can be configured to allow talkback audio to be
routed to one of three locations: intercom channel 1, intercom channel
2, or a line-level talkback output. The line-level talkback output is
transformer-coupled with a +4 dBu nominal signal level. It contains
resistors in series with the output connector, allowing line-level
talkback outputs from multiple units to be directly “summed.”
For non-on-air
applications, special Model 230 features can be enabled by placing the
unit in one of two production modes. Using these configurations the unit
can be even more powerful when used in live-event applications. With all
the available talkback flexibility, the exact needs of many specific
applications can easily be met. And, of course, whatever configuration
is implemented, the talkback audio quality will be excellent.
Dynamic
Range Control
To enhance the Model 230’s talkback
functions, a studio-quality compressor circuit is provided to control
the dynamic range of the signal coming from the microphone preamplifier.
Far from a simple “clipper,” the circuit utilizes a sophisticated
laser-trimmed voltage-controlled-amplifier (VCA) integrated circuit for
quiet, low-distortion level control. The signal from the compressor is
used by the talkback functions. This ensures that talkback audio signals
remain clear and intelligible under all real-world conditions. In
addition, dynamic range control is especially important when talkback
signals are being routed to intercom channels.
User
Controls and Status Indicators
Three pushbutton switches, four LED
indicators, and two rotary controls provide the user with a clear,
easy-to-use interface. One pushbutton switch controls the status of the
main output. This is the audio output intended for on-air, announcement,
or other primary uses. Two LEDs display the on/off status of the main
output. Two additional pushbutton switches control the status of the
talkback functions. These are the audio cue signals used to communicate
with producers, directors, “spotters,” or other behind-the-scenes
production personnel. A status LED is associated with each talkback
button. Two rotary controls allow the user to adjust the level of the
headphone output.
Flexibility
A large part of the Model 230’s unique
power is the ability to configure the operation of the main output and
talkback functions. To meet the needs of the many specific broadcast and
production applications, a variety of button operating modes is
available. The main output button can be selected to operate from among
four modes. In the “push-to-mute” mode the button performs a momentary
mute of the main output. In this way a “cough” button function is
created, something typically required for television sports
broadcasting. In the “push-to-talk” mode the button provides a momentary
active function for the main output. This mode would be appropriate for
applications such as stadium announcement. An alternate action
“latching” configuration allows the button to enable or disable the main
output as desired. This is useful in radio broadcasting, announce-booth,
or voice-over applications. The fourth mode provides a hybrid function,
supporting both push-to-talk and tap-to-enable/tap-to-disable operation.
This operation is similar to that found in many broadcast intercom
system user stations.
The two buttons associated with the
talkback functions can be configured to operate from either of two
modes. One of the modes supports a “push-to-talk” function. This is
typically used for on-air broadcast applications. The other mode
provides a hybrid function, the operation of which is discussed in the
previous paragraph. The hybrid mode is especially useful when the Model
230 is used in a production-support application.
The main button mode configures how the
main output, when it is in the “latched” on state, responds to talkback
activity. One choice momentarily turns off the main output when talkback
is active, returning the main output to the on state when the talkback
function has ended. The other choice “unlatches” the main output in
response to a talkback function.
IFB
Input
A broadcast-standard
“wet” (DC with audio) IFB circuit can be directly connected to the Model
230’s IFB input. Originated by sources such as the
Telex®/RTS® 4000-series IFB
system or IFB interface devices from Studio Technologies, the connected
IFB circuit can provide DC power to operate the Model 230 as well as two
channels of cue audio.
Cue
Sources
The
Model 230 supports the connection of up to six audio sources, each of
which can be selected for routing to the stereo headphone output. The
sources are IFB channel 1, IFB channel 2, line input 1, line input 2,
intercom channel 1, and intercom channel 2. Each source can be
individually assigned to the left channel, right channel, or both left
and right. This allows a wide variety of stereo and mono headphone mixes
to be created.
The two audio signals associated with
the Model 230’s IFB input can be assigned to the headphone output.
Originating in production trailers or control rooms, the IFB circuits
typically provide DC power and program-with-interrupt audio on one
channel and program-only audio on the other.
For application flexibility, two
line-level audio sources can be connected to the Model 230. Possible
signal sources include off-air receivers, wireless IFB systems, and
audio consoles. The connected signals can be from two independent
sources, or could be from a stereo audio feed such as would be
associated with a broadcast music event. Two level trim potentiometers,
located on the bottom of the unit, allow signals with wide nominal audio
levels to be cleanly interfaced.
Audio signals associated with a single-
or dual-channel intercom system can be routed to the headphone output.
The Model 230’s intercom interface is compatible with standard
party-line intercom systems from manufacturers such as Telex/RTS and
Clear-Com®.
Headphone
Output
Two rotary controls are
provided for user adjustment of the headphone output levels. For
application flexibility the actual function of the two “pots” is
configurable. For traditional on-air sports applications they can be
selected to the dual level control mode which provides independent
control of the left and right channel volume. For use with stereo cue
signals, or to support user preference, the level/balance mode can be
selected. In this mode one control adjusts the overall level of both the
left and right channels, while the other allows adjustment of the
left/right level balance. To help minimize the chance of broadcast cues
being missed, both level control modes can be configured so that a
minimum headphone output level is maintained. Alternately, the headphone
output can be set to fully mute when the controls are at their minimum
position.
A headphone control
reverse mode is provided specifically for on-air television applications
where a headset with boom microphone is used. The reverse mode ensures
that no matter which headset orientation is used by the talent, the
controls will always work intuitively. This results in a comfortable
work environment, allowing the left control to impact the level to the
talent’s left ear while the right control impacts the right.
Provision has been made
to support applications where a monaural cue feed is desired. A
configuration switch allows the summing (combining) of the selected left
and right headphone sources. In addition to creating a dual-channel mono
output it also allows the level controls to be configured as a simple
2-channel mixer. For applications where a single “muff” headset or IFB-type
earpiece is connected, another configuration switch can be used to
disable the headphone output’s right channel.
The headphone output
was designed to meet the needs of contemporary headphones and headsets.
Specifically, the output circuits act as voltage, rather than power,
drivers. In this configuration they can provide high output levels with
very low distortion and noise, along with minimal current consumption.
The output circuits are configured to safely drive stereo or mono loads.
This ensures that all types of headphones, headsets, and earpieces can
be directly connected.
Intercom Interface
Of special note is the Model 230’s
sophisticated intercom interface. It’s designed to work correctly with
industry-standard single- and dual-channel party-line intercom systems,
including those from Telex/RTS and Clear-Com. An intercom line connected to
the Model 230 can serve three functions: providing cue audio signals to
the headphone output, allowing talkback audio to be sent to intercom
users, and as a Model 230 power source. Audio signals present on the
single- or dual-channel intercom line can be flexibly routed to the
headphone output. Talkback audio can be sent to either or both intercom
channels. Trim potentiometers, located on the bottom of the unit, allow
adjustment of the talkback-to-intercom “sidetone” level.
Other announcer console products can
exhibit talkback-to-intercom-related audio oscillations (“squeals”) that
end up in the headphone output. A special Model 230 feature ensures that
this will never occur. This is accomplished by means of a special
“auto-terminate” circuit that becomes active whenever an intercom line
is not connected to the Model 230.
Active Sidetone Function
The Model 230 includes
a unique active sidetone function that’s available whenever the unit is
configured for one of the production modes. By routing audio from the
microphone input to the headphone output a user confidence (“sidetone”)
signal is provided. This allows a user to always hear what they are
saying, a critical requirement for effective communications. The word
“active” is part of the function’s name because it involves active
circuitry, under software control, to achieve excellent audio
performance. The sidetone level is dynamically configurable, allowing
the user to adjust the level as required.
Audio
Quality and Protection
The Model 230’s
circuitry is carefully tailored to provide excellent audio performance.
Professional-quality components are featured throughout. For reliability
all audio routing is performed using solid-state devices under
microcontroller direction. In all critical audio paths, “clickless”
electronic switches provide noise-free control. All audio inputs and
outputs make extensive use of protection components. This limits the
chance of damage from ESD and other undesirable, yet real-world, hazards.
Power
Sources
The Model 230 can
derive its operating power from the IFB input, intercom interface, or an
external 24 volt DC source. For redundancy, all three power sources can
be connected simultaneously. An internal switch-mode power supply
ensures that all Model 230 features are available, including phantom
power, when the unit is powered by any of the three sources.
The Model 230 is
compatible with IFB circuits provided by most standard broadcast
systems. However, maximum performance can often be obtained by using the
IFB interface devices available from Studio Technologies. Single-channel
and four-channel units are available, each providing high-quality audio
along with an excellent source of DC power. They’re directly compatible
with most matrix intercom systems, as well as standard line-level audio
signals.
Auxiliary Relay
Model 230 resources include a
general-purpose relay, allowing specialized configurations to be
created. Under software control, the relay can be configured to follow
the state of the main output, talkback 1, or talkback 2 buttons. Taking
advantage of the back-panel locations provided for additional XLR-type
connectors, a technician may easily implement a variety of functions
such as an “on-air” indicator or performing loudspeaker muting during
talkback. Special configuration modes are even included to allow direct
control of the relay using the talkback 1 or talkback 2 buttons without
impacting any of the unit’s audio signals. The auxiliary relay is also
used by the optional direct microphone output card.
Configuration
Model 230
configurations are made using a number of DIP-type switches and four
trim potentiometers. One 8-position switch array is used to set the gain
of the microphone preamplifier, the on/off status of phantom power, and
control of the headphone output modes. A 12-position switch array
configures which of the six cue audio sources are routed to the
headphone outputs. Two 8-position switch arrays communicate the desired
operating modes to the microprocessor. Two rotary trim pots
are used to adjust the input sensitivity of the line inputs. Two
additional rotary trim pots are provided to adjust the “sidetone” level
for the intercom interface’s talkback functions. All switches and trim
pots are accessible via the bottom of the Model 230’s enclosure; the
unit does not have to be disassembled. Changes made to any of the
configuration parameters become active immediately. To prevent access to
the configuration controls a security panel, included with each unit, is
attached to the bottom of the enclosure.
Connectors
The Model 230 uses standard connectors throughout. The microphone input,
line inputs, IFB input, and intercom interface functions use 3-pin
female XLR-type connectors. The main output and line-level talkback
output functions use 3-pin male XLRs. The headphone output utilizes a
¼-inch 3-conductor jack. The external source of 24 volt DC power is
connected by way of a 2.1 x 5.5 mm “locking” coaxial power jack.
In the world of broadcast and production
audio it’s fair to say that applications vary widely. To this end, up to
three additional XLR-type connectors can be easily mounted into the
Model 230’s back panel. Multiple 3-position “headers” located on the
Model 230’s circuit board provide technician-access to literally every
input and output connection. Using a factory-available interface cable
kit, these allow a Model 230 to be optimized to meet the exact needs of
specific applications. For example, some applications may prefer to use
a multi-pin XLR-type connector to interface with a headset. This could
be easily accomplished by adding the appropriate 5-, 6-, or 7-pin XLR-type
connector and making a few simple connections. Other applications may
benefit from having “mult” or “loop-through” connections, something
easily incorporated into a Model 230.
Options
In most cases the Model 230’s standard
resources are more than sufficient to support the desired application.
But special needs always seem to arise. To that end, several optional
cards are available. Each card contains an integral 3-pin XLR-type
connector, allowing simple installation into a spare connector position
on the Model 230’s back panel. The direct microphone output card
provides access to the dynamic or condenser microphone that is connected
to the Model 230. Passive components, along with the auxiliary relay
contact, create a “click-free” audio signal. The line output card allows
the Model 230 to provide a second line-level talkback output. The card
uses passive components, including an audio transformer, for reliable
signal interfacing.
200-Series Announcer's
Console Products
The Model 230 is just one in a series of
announcer console products available from Studio Technologies. The Model
230 was designed to support a variety of applications where a wide range
of features and flexibility is required. For applications whose
requirements are more limited in scope, the other products in the
200-series should be reviewed.
Model 230 Specifications
General
Audio:
Frequency Response: 20 Hz-20 kHZ, ±0.1 dB, mic in/main out
Distortion (THD+N): 0.008%, measured at 1 kHz, mic in/main out
S/N Ratio: 80 dB, referenced to –46 dBu mic in/–2 dBu main out
Connectors:
Mic In, Line In 1 & 2, IFB In, Intercom Interface: 3-pin female XLR-type
Main Out, Talkback Out: 3-pin male XLR-type
Headphone Out: ¼-inch 3-conductor phone jack
24 Vdc Power In: 2.1 x 5.5 mm coaxial power jack with locking bushing,
compatible with Switchcraft S760K plug
Spare
Connector Locations: 3
Allows up to three Neutrik NC*D-L-1 connectors to be installed (*=3F, 3M,
5F, 5M, 6F, 6FS, etc.)
Microphone
Input/Preamplifier:
Type: electronically balanced
Input Impedance: 2 k ohms
Gain Range: 20 to 60 dB, adjustable in 10 dB steps
Compatibility: dynamic or phantom-powered mics
Phantom Power: 48 Vdc, nominal, meets IEC 61938
Compressor:
Threshold: 2 dB above nominal level
Attack/Release Time: 2 mSec/100 mSec
Slope: 5:1
Status LED: compressor active
Line
Inputs: 2
Type: balanced, transformer-coupled
Impedance: 10 k ohms
Nominal Level: –12 dBV to +6 dBu, adjustable
IFB Input:
Type: 2-channel, unbalanced (pin 1 common; pin 2 DC with channel 1
audio; pin 3 channel 2 audio)
Impedance: 10 k ohms
Nominal Level: –10 dBu
Intercom Interface:
Type: 2-channel, unbalanced (pin 1 common; pin 2 DC with channel 1
audio; pin 3 channel 2 audio)
Compatibility: single- and dual-channel intercom systems such as from
Telex®/RTS® and Clear-Com®
Impedance: 10 k ohms
Nominal Receive Level: –10 dBu
Nominal Talkback Level: –10 dBu
Sidetone: 0 to –18 dB, adjustable
Main
Output:
Type: balanced, transformer-coupled
Nominal Level: –2 dBu
Maximum Level: +20 dBu into 2 k ohms
Impedance: 100 ohms
Talkback
Output:
Type: transformer-coupled with series capacitors and isolation resistors
Impedance: 600 ohms
Nominal Level: +4 dBu
Maximum Level: +11 dBu (compressor restricts maximum)
Headphone
Output: 1, stereo
Compatibility: intended for connection to mono or stereo headphones or
headsets with nominal impedance of 100 ohms or greater
Type: voltage driver
Maximum Output Voltage: 8 Vpp, 150 ohm load
Auxiliary
Relay:
Function: software configurable
Contacts: 2, form C (Common, Normally Closed, Normally Open)
Rating: 1 A, 30 W (resistive)
Access: requires user-implemented connector scheme
Power Sources:
IFB Input: 24-32 Vdc, 125 mA
Intercom Interface: 24-32 Vdc, 125 mA
External: 24 Vdc, 90 mA @ 24 Vdc; acceptable range 20-30 Vdc. Units shipped
to North America and Japan include a 120 V input/24 Vdc output power
supply. Units shipped to all other locations include a universal
input/24 Vdc output power supply.
Options: direct microphone output card, line-level output card
Dimensions
(Overall):
8.1 inches wide (20.6 cm)
3.3 inches high (8.4 cm)
8.5 inches deep (22.4 cm)
Weight:
4.5 pounds (2.1 kg)
Specifications
subject to change without notice.
Model 200-Series Announcer's Consoles
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Which
Announcer's Console is right for your application? Review the
Model 200-Series
Announcer's Consoles Feature-by-Feature Comparison Chart.
•
A
host of optional accessories can be added on to the
Model 200-Series Announcer's Consoles. For more information review the
Model 200-Series
Announcer's Consoles Accessories List.
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