Issue 6, September 2004
Model 50/51 User Guide
Page 18
Studio Technologies, Inc.
Switchcraft No. 297, Neutrik NP3C, or
equivalent will work correctly. Use a mo-
mentary, single-pole, single-throw switch
for each remote function. The respective
function is activated when the tip or ring
get shorted to the sleeve.
While the Model 51’s talk to studio and
talk to phones buttons can be configured
to latch, the remote control inputs are
always push to activate. This is provided
as a safety feature preventing an external
user from “latching” one of the functions
to the on state.
Mic Module Input
The Model 51 Control Console contains
a microphone which provides the audio
source for the Model 50’s communica-
tions functions. In special applications the
Model 51 may not be used, and a sepa-
rate source of communications audio will
be necessary. The Mic Module input on
the back panel of the Model 50 allows this
to be easily accomplished.
Even if you are using the Model 51 Con-
trol Console you may want to provide an
alternate source of communications audio.
To use your own microphone and preamp,
directly connect it using the Mic Module
input jack. The Mic Module input is a
¼
-inch 3-conductor phone jack with
+12Vdc on tip, audio input on ring, and
ground on sleeve. The audio input re-
quires a nominal –10dBu signal (–10dBu,
not –10dBV!). The +12Vdc on the tip is
from the same source that powers the
Model 51, and is provided to power an
external preamp. If you feel the urge to
use this power source, be aware that it
only provides 110 milliamps of current of
which the Model 51 needs about 100mA.
So go ahead and use all the current you
need, as long as it doesn’t exceed 10mA!
Note:
Communications audio from the
Model 51 is routed into the Model 50’s
circuitry through the normal connection
on the ring contact of the Mic Module
input jack. When a phone plug is inserted
into the Mic Module input, the audio path
from the Model 51 to the Model 50 is bro-
ken. This means you can’t use the Model
51’s microphone and the Mic Module
input at the same time.
Model 70 Interface
In most cases Model 35 and/or Model 38
Talents Amplifiers will be used to drive
headphones associated with a Studio-
Comm installation. In special cases a line
level signal may be required to interface
the Model 50 Central Controller’s talent
amplifier output with other audio equip-
ment. An example would be to use the
Model 50 with an existing headphone
system. The Model 70 Interface is used
to convert the talent amplifier signal to
a stereo, balanced line level signal.
Installation is very simple. Connect the
Model 70 to the Model 50 Central Con-
troller’s talent amplifier output using a
standard 3-conductor microphone-type
cable. For best performance, use low-
capacitance shielded cable.
Tip: +12Vdc
Sleeve: Ground
Mic Module Input
Ring: Communications
Audio Input
(Switchcraft No. 297, Neutrik NP3C, or equivalent)
