Studio Technologies 76B 2012 - Manual (Page 16)

Issue 3, August 2012 Model 76B/77B User Guide
Page 16 Studio Technologies, Inc.
for Surround
77B into a “rats nest” of schedules, memos
from management, and empty coffee cups!
But a firm press with the fleshy part of an
index finger should do the trick.
There is no problem frequently “tweaking”
the system’s operating parameters to achieve
the desired performance. The configuration
data is stored in nonvolatile memory, which
is rated for thousands of read and write
cycles and a retention time in tens of years.
Note that memory integrated circuits are
located in both the Model 76B Central Con-
troller and the Model 77B Control Consoles.
Only the individual device address is stored
in each Model 77B. All other configuration
parameters are stored in the Model 76B.
Model 77B Device Address
A unique device address must be assigned
to each Model 77B that is connected to a
Model 76B. The choices are A1, A2, A3, or
A4, with the default address being A1. As
most installations will find only one Model
77B utilized, its default setting is appropriate.
For installations that use a second, third, or
fourth Model 77B each unit must be config-
ured with a unique device address. Problems
will occur if more than one unit has the same
address! It’s important to highlight the fact
that the device address is the only setting
that must be done on each individual Model
77B unit. All other settings can be made on
any one of the connected Model 77B units.
Auxiliary Monitor Output
Nominal Level
The nominal level of the stereo (2-channel)
auxiliary monitor output can be configured
to match the requirements of a specific in-
stallation. Devices connected to the auxiliary
monitor output could include an amplifier
associated with a loudspeaker system or
inputs on self-contained amplified loudspeak-
ers. (These types of devices must include a
means of adjusting their output level.) This
configuration setting defines the analog out-
put level when a digital input source, at its
reference level, is connected and the auxil-
iary monitor output is enabled. The choices
are +4.0, 0.0, –6.0, or –12 dBu. When con-
necting to the input of a device that’s not
associated with a loudspeaker system most
applications will find the +4.0 dBu setting
correct as it meets the dominant worldwide
audio standards. For broadcast applications
that follow the PAL standards the 0.0 dBu
setting may be appropriate. Devices such as
amplified speakers will often perform better
when receiving signals with a lower nominal
level. In the latter case the ability to comfort-
ably use a level potentiometer may be greatly
enhanced using the –6.0 or –12.0 dBu set-
tings. The latter setting would be appropriate
when connecting the auxiliary monitor output
to the popular series of amplified loudspeak-
ers from Fostex®.
While sometimes not fully understood, using
the term dBu is more in line with contem-
porary audio applications than the outdated
dBm and the “semi-pro” dBV references; dBu
refers to audio levels without regard to their
load impedance, typical of situations where
an output has a low source impedance and
is connected to a high-impedance input. An
analog audio signal with a level of +4 dBu
has an RMS level of 1.228 volts. A 0 dBu
signal has an RMS level of 0.775 volts.
Digital Input Reference Level
Configuring the digital input reference level
to match the sources associated with a
specific installation is an important step
toward achieving optimal audio performance.
This ensures that the Model 76B’s digital au-
dio receiver integrated circuits are configured