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EXTERNAL INPUT/NR SWITCHING CARD:
MOD5X349
This card handles several functions related to external mag-
netic and digital signal sources, NR switching, and magnet-
ic modes. Source selection of digital or magnetic signals is
provided by electronic switching I.C’s. These determine
which signals appear on the main signal busses of the MOD
V. This is dependent on which format is selected. The Left
and Right NR cards are switched between optical and mag
sources, again dependent on the selected format.
This card also has 2 toggle switches to select various mag-
netic sound modes. The bottom switch selects MAG NR
ON or OFF. Since most mag prints use NR encoding
(Dolby 70), this switch is normally ON (up position). The
top switch selects mag mono surrounds or split surrounds.
Because most mag prints do not have split surrounds, this
switch should normally be left in MONO (down position).
DUAL PROJECTOR PREAMP CARD:
MOD4X300
There are 2 stereo solar cell preamplifiers in the MOD V:
each preamplifier channel is equipped with slit-loss correc-
tion. The Stereo-optical preamplifiers on this card increase
the incoming level from the stereo solar cells. Electronic
changeover circuitry between stereo pairs is built on the
card to allow use in dual projector booths. If the MOD V is
installed in a single projector booth, leave the second pro-
jector inputs unconnected.
The Dual Projector Preamp Card has two solar cell pream-
plifier gain controls and two slit-loss correction circuits for
each projector. There is sufficient gain built into the pre-
amps for narrow slit optical sound lenses when the exciter
lamp is run at 80% of its rated value. The card is silk
screened to make it easier to see the location of each pre-
amplifier gain and slit-loss correction control pot.
MONO/BACKUP CARD:
MOD2X305
The MONO card provides the necessary frequency response
shaping and level shifting to provide a quality mono signal
from mono prints. In addition, a special open ended noise
reduction circuit called Dynamic Noise Reduction is used to
eliminate much of the “hiss” and film scratch noise often
present on film. This card also provides the necessary drive
signal for the optional stereo synthesizer portions of the
MOD V.
The MONO card contains the necessary circuitry for the
emergency backup system in the event of loss of sound
within the MOD V processor. The multi-turn pot on this
card is for setting the emergency backup level.
