Audio Developments AD114 - Manual (Page 19)

18
ADJUSTMENTS AND CALIBRATIONS
Line-up-tone oscillator - the preset (VR3) that adjusts its level at the output of the
mixer is mounted on the output module printed circuit board.
Meter Calibration
The meter has only one calibration preset potentiometer per indicator bar; which
controls the adjustment of the level of the reading in relationship to the signal being
measured. All other aspects of the meter specification are taken care of within the
software and fixed values in the circuitry.
To gain access to the meter module the top panel holding the meter must be
detached from the main chassis. (Refer to Disassemble and Assemble Instuctions).
When the top panel has been detached from the chassis access can be gained to
the meter module by extending the ribbon cable connecting the meter module to the
main circuit board.
To adjust the meter calibration level apply a signal to an input and obtain the desired
calibration signal level from both outputs. Measurement can be made by applying a
millivolt meter or similar measuring device across pins 2 & 3 of the XLR associated
with the output under test. Adjust the associated preset potentiometer corresponding
to the output being measured to obtain the desired meter reading. (See diagram
below). Factory setting is a '0' reading on a PPM scale corresponds to 0dBu at the
output and to +4dBu at the output on a VU scale unless prior instuctions were
received at the time of ordering.
Left
Right
IC 1 N/A
PPM/VU ON=VU
ILL