Studio Technologies 50 2000 - Manual (Page 35)

Model 50/51 User Guide Issue 4, July 2000
Studio Technologies, Inc. Page 35
in the talent amplifiers, optimal perfor-
mance still requires an input close
to nominal.
The Model 38 Talent Amplifier can also
exhibit reduced performance if the level
of the headphone source is significantly
“hotter” than nominal. The entire system
has plenty of headroom, but maintaining
proper signal levels, as usual, is impor-
tant. If the source selected for head-
phones has an average level that is exces-
sive, a small amount of bleed-through can
be heard with the Model 38’s cue mix level
control set fully counterclockwise. Instead
of having no sound in the phones, a bit of
sound can be heard. This is not a design
problem; the Model 38 has a sensitive
preamplifier section which doesn’t like
excessive excursions in the left channel
modulation of the +23Vdc signal. The
Model 38’s power supply can reject the
left channel modulation within the design
parameters, creating a clean reference
voltage for the stereo preamplifier. Modu-
lation levels outside the design parame-
ters show up in the reference voltage!
Communication Switch Noise
During field trials of the StudioComm
components one item came up for discus-
sion concerning “thumps” in the commu-
nications functions. A brief discussion
may be useful. Electrically the Model 50
and Model 51 electronics that support the
communications functions are quite quiet,
not adding appreciable “clicks, pops, or
thumps.” Software time delays are even
added to minimize noise when the buttons
are pushed. Mechanical noise being
picked up by the Model 51’s microphone
can be an issue. If the talk to studio, talk
to phones, or slate buttons are pushed
using a relatively light touch no objection-
able noise will be generated; pressing the
switches with “gusto” will cause mechani-
cal noise to be transferred into the micro-
phone. While the Model 51’s microphone
is of good quality, shock mounting it was
not possible using a cost-effective method.
The fact that the Model 51 is physically
small and the buttons must be relatively
close to the microphone adds to the diffi-
culty. (Note that most all recording con-
soles, both small and large, share this
condition.)
What are the options if the operator(s)
of your Model 51 choose to use a “heavy”
hand on the switches? Two are readily
available: external communications
switches and an external source of com-
munications audio. A connector on the
back of the Model 51 allows the connec-
tion of external talk to studio and talk to
phones switches. Using external switches
can eliminate the transfer of noise into the
Model 51’s microphone. The Mic Module
connector on the back of the Model 50
allows an external source of communica-
tions audio to be substituted for the signal
provided by the Model 51’s microphone.
Using a microphone and simple preampli-
fier (or microphones and an inexpensive
mixer) you can optimize the sound quality
and location of the communications
mic(s). With the Model 51’s microphone
no longer in use, the switches can be
“beaten on” with no impact on communi-
cations audio. For details on how to imple-
ment external communication switches or
to use the Mic Module input refer to other
sections in the Advanced Installation Topis
section of the manual.