Manual

Issue 2, October 2018 Model 204 User Guide
Page 12 Studio Technologies, Inc.
MODEL 204
ANNOUNCER’S CONSOLE
the output is identical to the signal that’s
connected to the microphone input but with
a solid-state muting circuit in series with
the interconnection. When the Model 204’s
Dante main output channel is active the
microphone signal will also pass through to
the Model 204’s microphone output connec-
tor. Whenever the Dante main output chan-
nel is muted the microphone signal does
not pass through to the microphone output
connector; it is muted in an essentially
click-free manner. Refer to Appendix A for a
block diagram of the microphone input and
microphone output circuitry.
The microphone output can be connected
to balanced (differential) analog micro-
phone-level inputs on a variety of devices.
This includes microphone input connec-
tions on remote I/O interfaces associated
with a networked audio console. An ex-
ample of such an interface would be the
Calrec® Hydra2®. The mic inputs on these
devices typically offer microphone power,
high-quality amplification, and conversion
to the digital domain. The output signals of
the interface’s pre-amp channels are trans-
ported to the main electronics or console
surface using a fiber optic interface. In this
type of application the Model 204’s Dante
main output channel would not be used or
would only be used as a backup path.
No preamplifier or other active circuitry
impacts the path from the Model 204’s
microphone input connector to the Model
204’s microphone output connector. But the
signal does pass through a 200 ohm resis-
tor in each “leg” (pin 2 and pin 3) along with
connecting to a solid-state relay contact.
The result is that the source impedance of
a connected microphone will be 400 ohms
greater when presented to the microphone
output connector. This will slightly raise the
theoretical noise floor of the microphone
signal vis-à-vis a directly connected mi-
crophone signal but shouldn’t impact any
real-world applications.
Remote Control Inputs
Provision has been made to allow external
switches or contact closures to mimic
operation of the main and talkback push-
button switches. The exact functioning
of the two remote control inputs is deter-
mined by configuration settings, details
of which are discussed later in this guide.
A 3.5 mm 3-conductor jack is located on
the Model 204’s back panel and provides
access to the two remote control inputs.
The input circuitry is “active low,” with
3.4 k ohm resistors connected to +3.3 volts
DC to act as input “pull ups.” (In addition,
a combination of resistors and capacitors
provide ESD protection, minimizing the
chance of damage due to static discharge
or other extraneous signals.) A current flow
of less than one milliampere is required for
a remote control input to be recognized as
active.
Prepare the interconnecting cable and
associated 3.5 mm 3-conductor plug to
reflect that the tip lead is used by remote
control input 1, the ring lead by remote
control input 2, and the sleeve lead is the
connection to common.
Dante Configuration
For audio to pass to and from the Model
204 requires that several Dante-related
parameters be configured. These configu-
ration settings will be stored in non-volatile
memory within the Model 204’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.