Studio Technologies 68A 2005 - Manual (Page 16)

Issue 2, January 2005 Model 68A/69A User Guide
Page 16 Studio Technologies, Inc.
for Surround
To leave the confi guration mode and
return the Model 69A to normal operation,
once again press and hold the confi gure
button for two seconds. Note that confi gu-
ration changes are stored only after the
confi guration mode has been exited.
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 69A into a “rats nest” of music
scores or track sheets!
There is no problem frequently “tweaking”
the Model 69A’s operating parameters
to achieve the desired performance. The
confi guration data is stored in non-volatile
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
to disable the three unused channels.
Now when Surround B is selected, only
the relevant channels are selected for
monitoring.
Note that when a channel associated
with an input is disabled, the input routing
circuitry, 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 monitor output
channels will remain active, but the input
routing circuitry won’t select 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 simply would
not do!
A special mode has been included to
allow an input to be disabled 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.
To disable an input is simple, just disable
all channels associated with it; six for
Surround A and B, two for Stereo A and B.
To confi rm that an input has been dis-
abled, all LEDs associated with that input
will fl ash on and off. Once the Model 69A
is returned to the normal operating mode,
the disabled input cannot be selected.