9
INSTALLATION & OPERATION
the processor to any desired format, including music.
When the MODIIB is in music mode and any one of
the film formats are pulsed, the film sound will appear
at the main outputs, and the music will slowly fade
out. While the processor is in one of the film formats
and the music terminal is pulsed, the MODIIB will
fade from the film mode to music.
Note: The MODIIB powers up in Music mode.
DIGITAL INPUTS:
The MODIIB system has six inputs (Left, Center,
Right, Left Surround, Right Surround and Sub) via a
DB25 input connector marked DIGITAL INPUTS that
can be used to process the outputs from an external
digital decoder (i.e. DTS, Dolby Digital). The DIGITAL
INPUTS accept any high level multi-channel source.
The audio signals are processed through the individ-
ual equalizers, Output Card and Master VCA circuit
before they appear at the Main Outputs. These signals
do not pass through the Matrix or Time Delay circuits.
See the REAR CHASSIS DB25 SECTION for specific
pinout designation.
Another application of the Digital Input terminals is
for external sync sources. Sound-Interlock from a 35
mm reproducer or a single 16 mm projector may be
fed into the DIGITAL INPUTS and selected with the
front panel DIGITAL program switch on the MODIIB
Format Card.
REAR CHASSIS DB25 CONNECTOR:
The computer-type DB25 connector marked DIGITAL
INPUTS on the back of the processor is for an external
digital decoder. SMART provides the proper cables
for the different digital decoders available on the mar-
ket. See below for specific pinout configuration.
The DIGITAL DB25 inputs
Pin 1
Left
Pin 3
Center
Pin 5
Right
Pin 6
Left Surr.
Pin 7
Right Surr.
Pin 8
Sub
Pin 12 Digital Select
Pin 13 Stereo A / Stereo SR Default*
Pin 14-25 Ground
*see Default Optical Selection below
DEFAULT OPTICAL SELECTION:
External digital decoders available on the market have
a function that instructs the processor to switch to an
optical format in the event that the digital decoder
fails or loses time code. When this happens, the digital
decoder will pulse a special terminal to ground to alert
the processor to switch to the optical format.
On the MODIIB Digital DB25 input connector, this ter-
minal is the Stereo A / Stereo SR pin (see above). The
MODIIB will switch to either Stereo A or Stereo SR
depending on the location of a jumper (H3) located on
the Format Card.
The MODIIB is shipped to default to Stereo A in the
event of a digital decoder problem. In this default
mode, jumper H3 on the Format Card jumpers the
center pin to the “A” pin. For a default setting of
Stereo SR, you must move the H3 jumper to jump the
center pin to the “SR” pin. The factory default setting
of Stereo A should be adequate for most theatres.
However, if Stereo SR default is desired, then the
Format Card must be removed to access the H3
jumper. Make sure power is removed from the system
before removing any card or plugging one in.
OUTPUTS:
The MAIN OUTPUTS are labeled LEFT, CENTER,
RIGHT, LEFT SURROUND, RIGHT SURROUND,
SUB+ and SUB-. Shielded cable should be run
between these terminals and the next piece of equip-
ment in the sound system (equalizer, amplifier, etc.).
