Studio Technologies 58 1998 - Manual (Page 41)

Model 58/59 User Guide Issue 2, April 1998
Studio Technologies, Inc. Page 41
for Surround
impedance. This takes into account
today’s audio scene where signals have a
low source impedance, and a high input
impedance. The dBu designation is be-
coming the standard for the professional
audio industry.
“Hot” Disconnection of the Model 59
Control Console
Should you need to relocate the Model 59
while your StudioComm for Surround
system is operating, there is no reason
why you can’t disconnect the cable, move
the unit, and then connect it again. If the
Model 59 is disconnected while it is oper-
ating, the current operating parameters
are saved in nonvolatile memory and the
Model 58 Central Controllers will continue
to operate as they were when the link was
broken. No clicks, pops, or other noises
will occur when the Model 59 is again
connected. The Model 59 will go through
its standard power-up sequence, send a
message to reset power-up defaults, then
send the operating parameters as stored
in its memory. You may notice a brief
interval of silence while the Model 58s
respond to the reset defaults and operat-
ing parameter messages.
Power Amplifier Input Sensitivity
Optimum StudioComm for Surround per-
formance is obtained when the input
sensitivity of the associated audio power
amplifiers are adjusted to match the Model
58s monitor output level. With normal, but
loud, listening levels you should find the
level potentiometer on the Model 59 set to
about the “2-’clock” position. If you find
that you don’t have to turn up the Model
59’s control that high, reduce the input
sensitivity of the power amplifiers until you
get to the 2-o’clock position. Most power
amplifiers have controls on their inputs
to allow easy adjustment of the input
sensitivity.
Monitor Output Transient Protection
The Model 58 Central Controller contains
a power up/power down transient protec-
tion feature. This limits the chance of
damage to the monitor loudspeakers
during the time when AC mains voltage
is connected, disconnected, or has signifi-
cantly changed from nominal. A combina-
tion of hardware and software is used to
monitor one of the power supply “rails.”
Until the power supply exceeds 81% of its
nominal voltage, electromechanical relays
maintain a short circuit condition on the
A and B outputs. After a short delay the
relays are allowed to function normally.
Whenever the power supply drops below
79% of its nominal voltage, the relays
immediately go to their mute state. During
testing it was found that upon power up
the outputs remained very quiet; during
power down a moderate “tick” was the
worst that was heard.