Studio Technologies 760-02, 77 Data Sheet

Model 760-02 Central Controller / Model 77 Control Console

Overview

As creating and distributing multi-channel surround (5.1) and stereo audio material
has become a day-to-day reality, the ability to simply and effectively monitor these
sources is imperative for recording, post-production, and broadcast facilities. And
with audio-with-picture applications becoming so prevalent, additional monitoring
challenges have arisen. Studio Technologies has addressed these needs with the
StudioComm for Surround Model 760-02 Central Controller and the Model 77 and
Model 71 Control Consoles. With digital audio inputs, analog monitor outputs,
support for multiple user control surfaces, and an extensive set of operating
resources it’s a simple task to integrate a monitoring system into virtually any
facility. The carefully selected group of features, which includes surround and
stereo inputs and output, configurable input-signal time delay, configurable
downmix and mute/solo functions, and bass management, along with a multi­format sync input, make the system powerful yet simple to operate. And by
using the best of contemporary technology, as well as following rigorous design
practices, the system’s audio quality is excellent.

A StudioComm for Surround system starts with the Model 77 Control Console.
It’s the system’s “command center” and is designed to reside at a user’s location,
allowing fingertip selection of all monitoring functions. Numerous LED indica
tors provide complete status information. A 4-digit numeric display indicates the
monitor output level in real time. A major strength of the Model 77 is its ability
to configure, under software control, many important operating parameters.
Intended for secondary monitoring locations, the Model 71 Control Console is
a compact user control surface. It provides three of the most basic functions: a
rotary level control, dim on/off button, and reference level on/off button.

Key Features:

audio inputs

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Model 77 Control Console

• 5.1 surround and stereo balanced digital

5.1 surround and stereo analog outputs

• Balanced digital audio capability

• Allows use of multiple control consoles

• Superior audio quality

Most installations will use only one Model 77 Control Console. However, up to three additional Model 77 or Model 71 Control
Consoles can also be connected. This provides multiple users with full control over a facility’s monitor system. And to make instal
lation simple, the Model 760-02 provides power for all connected Model 77 or Model 71 units.

The core of this StudioComm for Surround system is the Model 760-02 Central Controller. The one-rack-space unit contains circuitry
that supports balanced digital audio inputs, balanced analog monitor outputs, digital processing of audio and control signals, and
interfacing for the user control surface(s). The Model 760-02 provides two surround (5.1) and three stereo digital audio inputs.
These balanced digital inputs are AES3-compliant; sources of this type are ubiquitous in many post-production and audio facility
environments. The inputs allow a sample rate of up to 192 kHz and a bit depth of up to 24 to be directly supported. Circuitry associ
ated with one of the stereo inputs provides sample rate conversion (SRC) capability, allowing a wide range of digital audio sources
to be monitored. Up to 340 milliseconds of input delay can be selected to compensate for processing delays in an associated video
path. For flexibility, two delay values can be configured, allowing real-time selection as desired. A number of different signals can
serve as the Model 760-02’s digital audio timing reference. For synchronization with a master timing reference a dedicated source
of word clock, DARS (AES11), bi-level video, or tri-level video can be connected. Alternately, the L/R connection of the actively
selected surround or stereo input source can serve as the timing reference.

Model 760-02 Central Controller Front Panel

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50250-0115, Issue 1

Model 760-02 Central Controller Back Panel

A surround (5.1) and a stereo analog monitor output are provided. They are intended for connection to monitor loudspeaker systems.
Electrically balanced, the monitor output signals provide low-noise, low-distortion, and high-headroom performance.

A sophisticated bass management function is integral to the Model 760-02’s design and can be enabled if desired. Note however that
the bass management function is only supported at sample rates of 44.1, 48, 88.2, and 96 kHz. The overall goal of bass management
is very simple: ensure that the entire audio bandwidth of all channels can be accurately monitored. Many loudspeaker systems
have inherent low-frequency limitations, preventing a true picture of the source material from being presented. To overcome this,
the low-frequency energy from the five channels associated with the surround inputs and the two channels associated with the
stereo inputs can be separated and routed to the subwoofer (SUB) channel of the monitor output. Several of the bass management
functions can be configured to match the requirements of specific installations.

Great care was taken in designing the system’s architecture, ensuring that the character of the audio input signals is preserved.
All audio processing, including bass management, is performed in 32-bit logic using a high-speed field-programmable gate array
(FPGA) integrated circuit.

The Model 760-02 occupies one space (1U) in a standard 19-inch rack. Digital audio sources
are interfaced with the Model 760-02 using one 25-pin female D-subminiature connector
and one 3-pin female XLR connector. A BNC connector is used to interface with an external
sync source. Analog monitor output signal connections are made using a 25-pin female
D-subminiature connector. One 9-pin female D-subminiature connector is used to connect
the Model 760-02 with a maximum of four Model 77 or Model 71 Control Consoles. A
second 9-pin “D-sub” connector is used to interface with remote control signals. AC mains
power is connected directly to the Model 760-02, with an acceptable range of 100 to 240
V, 50/60 Hz.

Additional Details

Model 71 Control Console

The Model 77 provides five buttons and associated LEDs for selection of the surround and stereo input sources to be monitored.
While in most cases only one input source will be monitored at a time, stereo input C can be selected for simultaneous monitoring
with one of the two surround or other two stereo inputs. This allows the two selected inputs to be combined (“summed”).

It’s interesting to note that while each of the two surround inputs has an LFE channel associated with it, the “.1” channel of the
surround monitor output is designated as SUB (subwoofer), rather than LFE. This terminology was carefully selected to highlight
the fact that this output channel may include more than just LFE content. The bass management function, if enabled, will redirect
low-frequency energy from the main input channels, combining it with the LFE content before routing the sum to the subwoofer
output.

The level of the surround and stereo monitor output channels can be controlled by way of a large, easy-to-use rotary control. The
control, actually a digital encoder, allows level selection in precise 0.5-dB steps. The auto mute all function causes the monitor
outputs to automatically mute whenever the output level control reaches maximum attenuation. Using the reference level function,
the monitor output levels can be set to a pre-configured value. This is provided for audio-with-picture applications that require
a specific monitor output level. The reference level is easily configured by taking an electronic “snapshot” of the desired monitor
output level. For user confirmation a 4-digit LED readout can display the level of the active monitor output. To match the needs of
a facility, it can be configured to display either the attenuation level or the sound pressure level (SPL).

The dim function allows the monitor output level to be reduced by a fixed dB amount. The dim level is configured from among
four available values. A mute all function allows the monitor output to be fully muted. The channel mute/solo section provides
individual channel monitoring control, allowing a single channel to be muted or monitored. Multiple channels can also be simul

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taneously selected for muting or “soloing.”

Studio Technologies, Inc. StudioComm 760-02/77, Issue 1, Page 2