Studio Technologies Gen II - Manual (Page 13)

Generation II User Guide Issue 3, July 1991
Studio Technologies, Inc. Page 15
listener the illusion of space, i.e., stereo!
Both op amp sections add gain according to
the position of the 3-position output level
switch.
The mono-compatibility of the Generation
II’s simulated stereo can be easily under-
stood by a careful study of how the stereo is
actually made. The output of network mod-
ule is really the “stereo information.” The left
channel is created by adding some of the
stereo information to the incoming mono
signal; the right channel is created by sub-
tracting the same amount. The amount
added and subtracted is directly related to
the setting of the front panel or trim stereo
intensity controls. When listening to the
simulated left and right output signals in
stereo, a feel of “space” is perceived. When
listening in mono, the left and right signals
are summed (added together), dropping out
the stereo information and giving the origi-
nal signal. The Generation II’s stereo infor-
mation exactly cancels out! What is added
to the left channel is subtracted from the
right.
This process holds true in the music and
music & voice modes. In the music mode,
full bandwidth delayed input audio is added
and subtracted. In the music & voice mode,
band-passed delayed input audio is added
and subtracted. In either case, perfect
mono compatibility is maintained.
Line Output Sections
The output stages use sophisticated, bal-
anced line driver integrated circuits. These
ICs are optimized for audio applications
such as the Generation II. Unbalanced
signal enters the ICs via the summing/gain
section for the left channel, and difference/
gain section for the right channel. The
nominal level fed to the ICs is
–
6,
–
2, or
+2dBu, depending on where the output
level switch is set. The line driver IC adds
6dB of gain, giving final nominal output
levels of 0, +4, or +8dBu. The line driver ICs
are capable of driving high signal levels into
600 ohm or greater loads, remaining stable
even when driving unbalanced loads. This
means that if one side of a line output is
grounded, the IC is not harmed and the
other side of the line output still functions
correctly. The output signals are direct
coupled to the XLR-type line output
connectors.
Troubleshooting
The following procedures must be
performed by a qualified technician.
Operating the Generation II with
the top and/or bottom cover removed ex-
poses the technician to points in the power
input section with hazardous voltages.
Equipment Required
• Low Distortion Audio (Sine Wave)
Generator, must have tone burst
capability
• Qty 2, AC Voltmeter, high input
impedance type
• Frequency Counter (200kHz minimum
measuring ability)
• Audio Distortion Analyzer, Sound
Technology 1710A or equal
• DC Voltmeter, high input impedance type
• Oscilloscope, Tek 465 or equal
• Test Probes for above
• Audio Cables as required