Studio Technologies 5130 2013 - Manual (Page 7)

Model 5130 User Guide Issue 5, July 2013
Studio Technologies, Inc. Page 7
Model 5130
Party-Line Interface Module
of party-line conditions. Unlike telephone-
line (“POTS”) oriented DSP-based hybrid
circuits, the Model 5130’s analog circuitry
maintains extended frequency response.
With this wide audio bandwidth, natural-
sounding voice signals can be sent to, and
received from, the connected party-line
user devices. This bandwidth also allows
high-frequency “call light” and “mic kill” sig-
nals to pass through to connected 4-wire
equipment.
The Model 5130’s sophisticated auto null-
ing function uses analog circuitry under
microprocessor control to achieve sig-
nificant trans-hybrid loss. This return-loss
“null” is achieved by making a series of
software-directed adjustments to account
for the resistive, inductive, and capacitive
conditions that are present on the con-
nected party-line user devices and associ-
ated cabling. Whenever a user presses the
Model 5130’s auto null button digital cir-
cuitry adjusts the 2-wire-to-4-wire hybrids
to achieve their maximum return-loss for
both interface channels. The nulling pro-
cess is automatic, lasting less than
15 seconds, and only takes place upon
user request. The resulting null parameters
are stored in non-volatile memory.
Audio Inputs and Outputs
Two analog line-level inputs and two out-
puts are associated with the 4-wire portion
of the Model 5130’s circuitry. These are
intended to interconnect with a variety of
devices, including matrix intercom sys-
tems, audio-over-fiber transport systems,
and specialized audio equipment. The
audio input and output circuitry is elec-
tronically balanced and capacitor coupled
to minimize the chance that hum, noise,
or interfacing issues will occur. The two
Model 5130 versions allow compatibility
with equipment that supports SMPTE (+4
dBu) and EBU (0 dBu) analog audio level
standards.
Indicators
The Model 5130 contains four 5-segment
LED level meters. Two meters display the
level of the signals being received from the
party-line channels and two display the
level being sent to the party-line channels.
At the time of installation and setup the
meters are invaluable in helping to confirm
correct operation. During normal operation
the meters offer rapid confirmation of the
audio signals flowing into and out of the
module. Three additional LED indicators
are also provided, offering status indica-
tions of the party-line DC power supply,
auto null, and remote control data func-
tions.
Pro Audio Quality
The Model 5130’s audio circuitry was
designed in the spirit of professional audio
equipment rather than that found in typical
party-line intercom gear. High-performance
components are used throughout, provid-
ing low-distortion, low-noise, and high
headroom. The party-line DC power source
offers a unique level of performance—its
ability to deliver power while maintaining
audio quality is simply unmatched.
Installation
Integration of the Model 5130 into the
selected application is quite simple, only
requiring connecting analog audio inputs
and outputs along with DC power. Some
applications will also require connection
to the RS-485 data bus. The audio signals