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MICROPHONE PREAMPLIFIER
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Instruction Manual
4. FUNCTIONS IN DETAIL
Local Control
The LOCAL button allows front panel control. Press it once, you’re in local. Press it again,
you’re back in remote. The LOCAL button is lighted when the 1788A is in the local state
and dark in the remote state.
NOTE:
None of the front panel buttons will be lighted while the 1788A is in the remote
control state.
While in local control state, all remote control is rejected. Because the 1788A was created
to be used primarily in remote controlled applications, the local control state is deemed to
be temporary, for emergency or infrequent control. To prevent permanent remote control
lockout,
the local control state will time out automatically five minutes after the
last front panel operation was detected.
When in the remote control state, every front panel control is locked out except
for the LOCAL and MONITOR SELECT buttons.
Depress the LOCAL button once to
regain control of the front panel.
Store Upon Release of Local Control
Whether the control state is set back to remote manually with the Local button or through
the automatic time-out feature, all the settings on the Model 1788A will be stored upon
entering the remote control state. This insures that the locally made changes will not revert
to the prior state and will become the new default condition upon power-up.
Remote Activity LED
Flashes when the Model 1788 is receiving remote control data.
4.3 DIGITAL BLOCK
NOTE:
This block is only active with the optional digital module
inserted into the rear panel of the Model 1788A.
Clock
The CLOCK button selects either the internal (Int.) or an external (Ext.) digital clock as a
synchronization reference and the corresponding LED will illuminate depending on which
one is selected.
When the Int. mode is selected, the 1788A locks to an internal clock generator that can
be set at one of three sample rates (32k, 44.1k and 48k) using the SAMPLE RATE button.
The chosen sample rate is displayed in the Global Status Readout.
In the Ext. mode, external clock is taken from one of two sources (BNC Word Clock In or
the DB-25 TDIF) on a
priority
basis. The highest priority input is the
Word Clock
. If no
Word Clock is detected, the 1788A then tries to lock to the
TDIF
.
NOTE:
In Ext. mode, the incoming sample rate is displayed in the Global Status
Readout. The indication will be of the nearest standard rate of 32, 44.1, 48, or 96KHz,
and not a precise frequency measurement.
