Studio Technologies 210 2012 - Manual (Page 11)

Model 210 User Guide Issue 5, September 2012
Studio Technologies, Inc. Page 11
Connecting devices with a nominal imped-
ance of 100 ohms or greater is preferred.
This shouldn’t prove to be an issue as es-
sentially all contemporary devices already
meet this condition.
Devices are connected to the headphone
output by way of a ¼-inch 3-conductor
phone jack located on the Model 210’s
back panel. As is standard for stereo
headphones, the left channel is connected
to the “tip” lead of the ¼-inch headphone
jack. The right channel is connected to
the “ring” lead of the jack. Common
for both channels is connected to the
“sleeve” lead.
Devices with ¼-inch 2-conductor “mono”
plugs can also be used with the Model
210’s headphone output. In this arrange-
ment only the tip lead (left channel) will
be active. The 2-conductor plug will physi-
cally connect (“short”) the ring lead
(right channel) to the sleeve lead (com-
mon). Technically this won’t damage
the circuitry associated with the right-
channel headphone output. (51 ohm
protection resistors are electrically in
series with the headphone output circuits.)
However energy will be wasted if an
audio signal coming out of the right chan-
nel goes into a “dead short.” There is a
simple solution to this issue. No audio
source should be assigned to the right-
channel headphone output. Refer to the
Configuration section of this user guide
for details.
Main Output
The main output is intended to be the
“on-air” signal that connects to the input
of an audio console. The output is trans-
former balanced with a nominal signal lev-
el of –2 dBu. The actual level will depend
on the gain setting of the microphone
preamplifier, sensitivity of the microphone,
and how loudly the talent speaks into the
microphone. The transformer used in the
main output is intended for professional
broadcast applications. It has a low source
impedance and can drive lengthy cable
runs with no difficulty. It is capable of driv-
ing 600 ohm loads but performs best with
loads of 2 k ohms or greater. (This should
not prove to be an issue as virtually all con-
temporary audio equipment has a relatively
high input impedance.) As the secondary
winding of the output transformer con-
nects directly to the main output connector,
care should be taken so that DC voltage is
never present on the interconnecting cable.
The main output is interfaced by means
of a 3-pin male XLR connector located on
the Model 210’s back panel. The intercon-
necting cable’s mating connector (female)
should be wired so that signal high (+ or
hot) is on pin 2 and signal low (– or cold) is
on pin 3. The cable’s shield can be con-
nected to pin 1, but it will have no function.
To limit the chance of grounding interaction
between the Model 210 and connected
equipment, pin 1 on the main output’s
connector is isolated from any point in the
Model 210. The fact that pin 1 “floats” will
minimize the chance of hums, noises, or
buzzes being present on the equipment
connected to the main output.
Talkback Output
The talkback output is intended for connec-
tion to control rooms, production trailers,
or other locations where talent- originated
voice cues are required. The talkback out-
put is transformer balanced with a nominal
level of +4 dBu. To enhance talkback
audio quality, the compressor circuit
controls the dynamic range of the signal
coming from the microphone preamplifier.