Studio Technologies 74 - Manual (Page 17)

Issue 2, January 2006 Model 74/75 User Guide
Page 18 Studio Technologies, Inc.
for Surround
Our apologies to those of you who fi nd the
confi gure button a pain to use, but it’s sup-
posed to be that way! Seriously, the top
of the button is slightly recessed from the
back panel, making it harder to accidental-
ly activate. We didn’t want normal opera-
tion to cease because someone pushed
the Model 75 into a “rats nest” of music
scores or track sheets!
There is no problem frequently “tweak-
ing” the Model 75’s operating parameters
to achieve the desired performance. The
confi guration data is stored in nonvolatile
memory, which is rated for thousands of
read and write cycles and a retention time
in tens of years.
Input Channels Active
This confi guration is a bit tricky to un-
derstand, but is really quite simple. The
confi guration parameter for the number of
channels active for each input is provided
for those special cases where a source
has less channels than its usual, e.g., less
than six for Surround A or B.
Let’s look at an example. Surround A
is connected to a 6-channel source, so
its default confi guration is fi ne. But the
source for Surround B is special, having
only three channels: left, center, and right.
This makes it not so “cool” for the opera-
tor to select Surround B for monitoring, as
the unconnected left surround, right sur-
round, and LFE channels will get routed to
their respective monitor outputs. Will the
unused input channels pick up signifi cant
noise or hum? Unlikely, but why take a
chance at having a problem. Simply use
the input channels active confi guration
function to disable the three unused chan-
nels. Now when Surround B is selected,
only the appropriate channels are selected
for monitoring.
Note that when a channel associated with
an input is disabled the input routing cir-
cuitry, under software control, no longer
selects it, but the corresponding monitor
output channel does not mute. With our
example, when selecting Surround B, our
mythical L/C/R source, all selected monitor
output channels will remain active, but the
input routing circuitry won’t enable the LS,
RS, and LFE inputs. While to some people
this might seem confusing and possibly a
design fault, it was implemented this way
because the StudioComm system allows
multiple inputs to be simultaneously select-
ed for monitoring; a surround source might
be selected at the same time as a stereo
source. Muting the outputs in response to
a single input channel being selected sim-
ply would not do!
A special mode has been included to
disable an input from being accessed by
the operator. This might be useful, for
example, when Stereo B is not connected
to a source, and has no valid reason to
be selected. This might also be useful
when connecting a special source, such
as a house “tie line” or router output, that
shouldn’t normally be accessible. Disabling
an input is simple to perform, just disable
all channels associated with it; six for Sur-
round A and B, two for Stereo A and B. To
confi rm that an input has been disabled, all
LEDs associated with that input will fl ash
on and off. Once the Model 75 is returned
to the normal operating mode the disabled
input cannot be selected.
Speaker Systems/Monitor Outputs
The confi guration parameters associated
with the speaker system selection button
and monitor output channels offer an ex-
tremely powerful resource. With just a few
button presses a wide range of monitor
system implementations can be easily