Studio Technologies 40 - Manual (Page 22)

Model 40 User Guide Issue 1, July 1994
Studio Technologies, Inc. Page 23
integrated circuit operational amplifier via
resistors and a switch which performs the
mono function. In the mono position the
switch connects the left channel signal to
the right channel amplifier, and drops the
level by 6dB. The op amp is configured as
a summing amp, allowing the signal from
the cue mix pot to be summed (mixed)
with the signal from the talent preamplifier.
The op amp, along with two transistors
and supporting components form the left
channel output stage. A low pass filter in
the feedback loop is included for stability.
The amplifier’s output is capacitor coupled
via a series resistor to the output connec-
tor. The capacitor changes the audio
output signal from being biased by the
+9.5V reference voltage to being biased at
signal common. The series resistor limits
the output current in the event of a shorted
output load.
Specifications
Model 40 Central Controller
Mounting
One space in a standard 19-inch (48.3cm) rack
AC Mains Requirement
100, 120, or 220/240V, ±10%, factory configured,
50/60Hz, 100-120V 0.4A maximum, 220/240V
0.2A maximum
Fusing
Qty: 1
Type: 5 x 20mm time lag (Littelfuse 218-series or
equivalent)
Rating: 0.400A for 100 and 120V mains power,
0.200A for 220/240V mains power
Connectors
Audio Inputs: dual, ¼-inch, 3-conductor phone
jacks, gold-plated contacts. (Manufactured
by Neutrik.) Mates with all plugs specified by
EIA RS-453.
Talent Amplifier Output Groups: 3-pin XLR-type,
male (Neutrik)
AC Mains: standard 3-blade plug, meets IEC 320
specifications
Audio Inputs
Qty: 2, stereo (separate left and right input
connectors)
Type: electronically balanced, direct coupled,
compatible with balanced or unbalanced signals
Impedance: 50k ohms
Nominal Input Level: –10dBV to +10dBu
Input Level Control: allows calibration over –10dBV
to +10dBu input range
Maximum Input Level: +27dBu balanced, +21dBu
unbalanced
Common Mode Rejection: 100dB @ DC and 60Hz,
70dB @ 20kHz, 62dB @ 40kHz (typical)
Talent Amplifier Outputs
Application: provides power and audio signals for
two groups of up to 4 Model 35 or Model 38 Talent
Amplifiers (total 8 talent amplifiers). The output
connectors (3-pin XLR-type, male) have common
on pin 1, +23Vdc modulated with left channel
audio at –10dBu on pin 2, and right channel audio
at –10dBu on pin 3. Maximum output current
200mA (nominal)
Frequency Response, Distortion (THD+N),
S/N Ratio: refer to Model 35 and Model 38
specifications
LED Indicators
Qty: 7, power present, signal present (4), over
current (2)
Dimensions (Overall)
19.00 inches wide (48.3cm)
1.72 inches high (4.4cm)
8.75 inches deep (22.2cm)
(1 standard rack space)
Weight
8.8 pounds (4.0kg)