Studio Technologies 68A 2001 - Manual (Page 16)

Issue 1, March 2001 Model 68A/69A User Guide
Page 16 Studio Technologies, Inc.
for Surround
To leave the configuration mode and
return the Model 69A to normal operation,
once again press and hold the configure
button for two seconds. Note that configu-
ration changes are stored only after the
configuration mode has been exited.
Our apologies to those of you who find the
configure button a pain to use, but it’s
supposed to be that way! Seriously, the
top of the button is slightly recessed from
the back panel, making it harder to acci-
dentally activate. We didn’t want normal
operation 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
configuration 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 configuration is a bit tricky to under-
stand, but is really quite simple. The con-
figuration 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 configuration is fine. But the source
for Surround B is special, having only
three channels: left, center, and right. This
makes it not so “cool” for the operator to
select Surround B for monitoring, as the
unconnected left surround, right surround,
and LFE channels will get routed to their
respective monitor outputs. Will the un-
used input channels pick up significant
noise or hum? Unlikely, but why take a
chance at having a problem. Simply use
the input channels active configuration
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 se-
lected 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 Sur-
round A and B, two for Stereo A and B.
To confirm that an input has been dis-
abled, all LEDs associated with that input
will flash on and off. Once the Model 69A
is returned to the normal operating mode,
the disabled input cannot be selected.