Studio Technologies 80 M80-00273, Руководство пользователя

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Model 80 User Guide Issue 4, March 1997
Studio Technologies, Inc. Page 11
Connection Wire Color
Neutral (N) Light Blue
Line (L) Brown
Protective Earth (E) Green/Yellow
Safety Warning: The Model 80 does
not contain an AC mains disconnect
switch. As such the mains cord plug
serves as the disconnection device.
Safety consideration requires that
the plug and associated outlet be
easily accessible to allow rapid discon-
nection of mains power should it prove
necessary.
As soon as mains power is connected, the
Model 80’s power present LED will light.
The unit is now ready for years of trusty
service!
Configuration
Input Level Calibration
With the ExactCal calibration section it’s
simple to match the nominal level of the
input signal with the Model 80’s internal
circuitry. Two controls, level and right trim,
along with four LEDs are the ExactCal
operator controls. The level control is a
stereo device, adjusting the input sensitiv-
ity for both the left and right inputs. The
right trim control allows the input sensitiv-
ity for the right channel to be adjusted
over a 3dB range. This allows compensa-
tion to be made for small differences in
the left and right input levels. Two LEDs,
labeled Lo and Hi, are associated with
each input. They are provided as an aid
to calibration, as well as serving as “signal
present” indicators.
The following is a step-by-step procedure
for using the ExactCal section to match an
input signal with the Model 80:
• Set the level control fully counterclock-
wise (all the way to the left end of the
travel).
• Supply a 1kHz sine wave to both the
left and right line inputs. Set the level
of the source to be precisely the nomi-
nal operating level. If, for example, the
output of a console is connected to the
input of the Model 80, the console
output should be adjusted so that the
meters read 0dB or 100%. If the output
of the console is a “+4-type,” then
setting the console’s left and right
output levels to nominal should find
the console output levels to be exactly
+4dBu.
• Slowly turn the level control clockwise.
As you increase the level, watch the
LEDs associated with the left channel.
The LED labeled Lo will light first, then
both LEDs will light, then only the LED
labeled Hi will light. The correct setting
is where both LEDs light. Careful
adjustment is required as the “window”
where both LEDs light is somewhat
less than 1dB.
• Observe the LEDs associated with the
right channel. If they are both lit no
adjustment of the right trim control is
required. If only one is lit adjust the
right trim control, using a small flat
blade screwdriver, so that both LEDs
light. (We like the Xcelite R3324 screw-
driver—it has the clear green handle
and is commonly used to calibrate
audio equipment.)