Studio Technologies 34 - Manual (Page 6)

Issue 1, August 2005 Model 34 User Guide
Page 6 Studio Technologies, Inc.
Model 34
Talent Amplifier
There may be cases where only one
audio source is provided by an IFB circuit.
Depending on the type of IFB equipment
supplying the circuit, the signal will either
be on pin 2 or pin 3 of the associated
XLR-type connector. In general, when
a single audio source is present a monau-
ral headset or earpiece will be connected.
These user devices will typically employ a
monaural (2-conductor) ¼-inch or 3.5 mm
plug. These plugs provide only tip and
sleeve leads which will only connect to the
Model 34’s left output. If the audio source
is arriving on pin 2 of the IFB circuit, the
mode switch should be placed in the
stereo position. The channel 1/left control
will be used to adjust the output level. If
the audio source is arriving on pin 3, the
mode switch must be placed in the mono
position. This creates a mono signal by
combining the two post-level-control sig-
nals, in this specific case sending the pin
3 audio source to both the left and right
outputs. Then the channel 2/right control
will be used to adjust the output level.
Connecting Multiple Headsets
or Earpieces
As previously discussed, the Model 34’s
output circuitry is protected from overload
and short-circuits. This makes it possible
to connect more than one earpiece or
headset to the Mode 34’s output connec-
tors. However, there are two limitations
when connecting multiple devices. The
first is that all of the connected devices
will “share” the one set of level controls.
Users will not be able to independently
set their listening levels. The second limi-
tation is that the load impedance placed
on the output circuitry will be significantly
less than any individual device. This
may cause the maximum output level
to be reduced because of the lower total
impedance.
DC Power Draw/Maximum
Number of Connected
Devices
Unlike previous-generation listen-only
devices, the Model 34 is quite efficient
in its use of operating power. During
normal operation the current draw is
nominally 20 milliamperes. This will allow,
conservatively, up to six units to be con-
nected to a typical broadcast IFB circuit.
Party-line intercom circuits often have
greater current support capability. In this
case connection of ten or more Model 34
units shouldn’t prove to be an issue.