Studio Technologies 68A 2005 - Manual (Page 14)

Issue 2, January 2005 Model 68A/69A User Guide
Page 14 Studio Technologies, Inc.
for Surround
panel (adjacent to the power entry con-
nector) for the factory-confi gured voltage.
Note that an incorrect confi guration could
prevent operation, or cause damage to
the unit. Should it be necessary to change
the unit’s operating voltage it must be per-
formed only at the factory or by an autho-
rized service technician.
The Model 68A uses an IEC-standard
connector to mate with the AC mains
cord. The wire colors in the AC mains
cord should conform to the internationally
recognized CEE color code and must
be wired accordingly:
Connection Wire Color
Neutral (N) Light Blue
Line (L) Brown
Protective Earth (E) Green/Yellow
Safety Warning: The Model 68A does
not contain an AC mains disconnect
switch. As such, the AC mains cord
plug serves as the disconnection de-
vice. Safety considerations require that
the plug and associated outlet be easily
accessible to allow rapid disconnec-
tion of AC mains power should it prove
necessary.
As soon as AC mains power is applied,
the Model 68A’s power present LED will
light. The Model 69A will go through a
power-up sequence, lighting each LED
in secession. The data active LED on
the Model 68A will briefl y light upon
completion of the Model 69A’s power-up
sequence.
Confi guration
After the physical installation has been
completed, several confi guration issues
must be addressed. On the Model 68A
the surround and stereo inputs must be
calibrated using the trim potentiometers.
The operating parameters of the system
should be set using the Model 69A Control
Console’s confi guration mode.
Level Calibration
Sixteen 15-turn trim potentiometers are
located on the front panel of the Model
68A Central Controller. Taking time to
carefully adjust the trim pots will ensure
that accurate monitoring can take place.
Each trim pot allows input signals with a
nominal level of –12 dBV to +6 dBu to be
utilized. With care, it’s easy to calibrate the
surround and stereo inputs to within one-
quarter of a dB of the desired value.
The monitor outputs are used as the
measuring point when adjusting the trim
pots. A laboratory-grade audio level me-
ter, or equivalent, is required for accurate
calibration. In addition, the audio sources
connected to the inputs must be able to
generate continuous audio signals at their
nominal operating level.
Procedure
This procedure will calibrate the surround
and stereo input channels. The trim pots
will be adjusted in groups corresponding
to their associated input sources.
1. Begin by turning the audio amplifi ers
or amplifi ed speakers to their off state.
This will protect the loudspeakers
and the operator’s ears from possible
damage.