Audio Developments AD114 - Manual (Page 18)

17
This module controls the level of main and monitor output signals and metering of
the output signals. Calibration is achieved when the stereo output level control (9) is
at maximum.
(1) Meter reads left output, right output and PFL level.
Battery status is read on the meter and the meters may be illuminated by ILL (11) -
overuse of this function will rapidly drain the batteries. When the internal voltage
drops below a safe operating level the battery status reading is at the lower limit of
the BATT mark.
The main output signal is metered and monitored after the output level control and
limiters.
A pair of limiters may be switched in to the main output - LIM (7) - and linked for
stereo operation - LINK (6). LEDs (8) indicate when limiting is taking place. The
factory setting for onset of limiting is +8dBu at the main outputs. Refer to
Adjustments and Calibrations section of this manual, if a different setting is required.
Line-up tone, when selected (5), replaces the normal signals on the main output.
Line-up tone is calibrated on the (BBC-scaled) meters to PPM4, giving a line output
level of 0dBu with the output faders set to maximum. On a VU scaled meter the
calibration is OVU giving a line output level of +4dBu.
The remaining controls are associated with headphone-monitoring of signals from
the mixer - internal signals (DIR) or tape-return (RET) maybe selected (14): these
signals may be either in the L-R domain or the M-S domain. When switches (14),
(15), and (16) remain unselected the main-output signal from the mixer appears on
the headphones. If SW (15) is selected, the left-output signal appears on both
earpieces; if SW (16) is selected, the right-output signal appears on both earpieces.
If switched (15) + (16) are selected, a matrix amplifier is inserted across the monitor
output: when the main output is in the L-R domain, the matrix will enable mono
compatibility to be assessed on the left earpiece and out of phase components to be
checked on the right earpiece. When working entirely in the M-S domain, the matrix
will transform the mixer output into the L-R domain for monitoring purposes.
Selection of RET (14) will allow these functions to be performed on a tape-return
signal. The level of the monitor signal is controlled by potentiometer (17). The level of
the return signal is controlled by a present potentiometer (13). This allows for
calibration of the return signal. For an OdBu signal, the system is calibrated when the
preset is fully counter-clockwise. From that point 20dB gain is available for lower
level signals.
The signal from the internal microphone (4) allows the mixer operator to add a voice
signal to the main output by operating the switch marked SLATE (3). The level is
controlled and set by preset potentiometer (12).