Manual

Model 381 User Guide Issue 2, March 2020
Studio Technologies, Inc. Page 9
MODEL 381
ON-AIR BELTPACK
or P48 phantom powered microphones. A
microphone should be connected such that
its common is on connector pin 1, its signal
high (+) is on connector pin 2, and its sign
low (–) is on connector pin 3. An STcon-
troller configuration setting allows the P48
microphone power sources to be enabled or
disabled as desired. Details on configuring
the unit will be described later in this guide.
Headphone Output
The Model 381 provides a 2-channel
(“stereo”) headphone output by way of a
3-conductor ¼-inch phone jack. Devices
such as stereo headphones or “dual-ear”
broadcast-style headsets can be directly
connected using a 3-conductor ¼-inch
plug. Following the usual convention the
left channel should be terminated on the
tip lead, the right channel on the ring lead,
and common on the sleeve lead.
It’s also possible to use a monaural (“single-
ear”) headset or broadcast-type single
earbud as long as sufficient care is taken.
If a 3-conductor ¼-inch plug is used by the
device it should be wired such that the tip
lead is connected to the positive terminal
of the transducer and the sleeve lead is
connected to the negative or common lead
of the transducer; the plug’s ring should
be left unconnected. But it’s also likely that
the monaural device will be terminated on
a 2-conductor (tip and sleeve) ¼-inch plug.
When a plug of this type is inserted into the
Model 381’s headphone output connector
(jack) the Model 381’s right headphone out-
put channel will be shorted. (This will occur
since the ring lead will be directly shorted to
the sleeve lead.) This can lead to stress on
the Model 381’s right channel headphone
output circuitry as well as drawing extra cur-
rent from the output stage. To prevent this
condition the Headphone Output – Controls
(A/B) mode configuration choice should be
set for Single-Channel Mono. This disables
the right headphone output channel and
sends the listen audio source or sources
only to the left headphone output channel.
Refer to a later section in this guide for de-
tails on configuring the headphone output.
Dante Configuration
For audio to pass to and from the Model
381 requires configuration of several
Dante-related parameters. These configu-
ration settings will be stored in non-volatile
memory within the Model 381’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 Con-
troller are available to support Windows and
OS X® operating systems. The Model 381
uses the Ultimo 2-input/2-output integrated
circuit to implement the Dante architecture.
The two Dante transmitter (Tx) channels
associated with the Model 381’s Dante
interface must be assigned to the desired
receiver (Rx) channels. This achieves rout-
ing the Model 381’s two output audio chan-
nels to the device (or 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 chan-
nels) to a receiver flow (a group of input
channels). The number of transmitter flows
associated with an Ultimo integrated circuit
is limited to two. These can either be uni-
cast, multicast, or a combination of the two.
If the Model 381’s Dante transmitter chan-
nels need to be subscribed (routed) to more
than two flows it’s possible that an interme-
diary device, such as the Studio Technolo-
gies’ Model 5422 Dante Intercom Audio
Engine, can be used to “repeat” the signals.
The two Dante receiver (Rx) channels as-
sociated with the Model 381’s audio inputs