Studio Technologies 40 - Manual (Page 12)

Model 40 User Guide Issue 1, July 1994
Studio Technologies, Inc. Page 13
The bottom surface of the Model 38 Talent
Amplifier contains two threaded inserts that
will accept English-standard ¼-20 screws.
Using two,
5 /
8
-inch long, round-head ma-
chine screws, the 25 Series clamp assem-
bly can be directly attached. The cover of
the Model 38 does not have to be removed.
Configuration
Input Level Calibration
Optimal performance of the Model 40 and
associated talent amplifiers depend on the
correct setting of the input level controls.
Each of the two stereo input sections con-
tain an input level potentiometer and two
Signal Present LEDs. The level control is a
stereo device, adjusting the input sensitivity
for both the left and right inputs. The Signal
Present LEDs are provided for assistance
during adjustment of the pot, as well as for
general signal present indication.
The following is a step-by-step procedure
for using an input control to match an input
signal to the Model 40:
• Set the input 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
nominal operating level. If, for
example, the output of a console is
connected to the input of the Model 40,
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
Signal Present LEDs. The correct
setting is just at the point where both
LEDs light.
• For future reference it may be helpful
to mark the correct input level and
right trim adjustment points. Use a
grease pencil or a piece of adhesive
tape so as not to damage the front
panel.
• Disconnect the 1kHz signal and
connect the normal audio source.
Operation
Now that you’ve installed and set the input
level controls, you’re ready to go. You
should find system operation very easy, as
there is almost nothing to do on a day-to-
day basis except adjust the output levels
on the talent amplifiers. For peace of mind,
the Signal Present LEDs will give you a
visual indication whenever audio signals
are present on the Model 40’s inputs.
In most cases the input level controls
shouldn’t be changed, as they will effect
the input calibration. If you change the
input source you can use the input level
control and the Signal Present LEDs to
recalibrate the input.
Model 40 Central Controller
The Model 40’s front panel contains seven
LEDs, two controls, and two switches.
The power present LED should be lit
whenever AC mains power is connected
to the Model 40. During normal operation
the two Over Current LEDs will not be lit.
They will flash only if there is a problem
with a talent amplifier or associated wiring.