Junger Audio d02 - Digital Dynamics Processor - Manual (Page 15)

2. INSTALLATION
2.4.
Setting the Digital
Reference Level
The static characteristics of the processor d 02 are related to the digital
reference level.
This internal digital reference level is the maximum output level for the
limiter and the reference level for the static compressor characteristics.
The rotation point for the compressor characteristics with zero gain is
allways situated at the internal digital reference level.
In order to adjust the digital reference level it is necessary to
change the operating mode of the unit as follows. Hold down the
display button continuously for a few seconds and the unit will enter
digital reference level adjustment mode. Pressing the INC or DEC
buttons on can change the digital reference level in the range of 0 dBFS
till -15 dBFS.
It is possible to store two different digital reference levels, one for
use when the analog signal input is selected and another different
setting for use when the digital input signal is selected. When
changing the input selection between analog and digital the required
reference level setting is automatically selected. So it is very easy to
optimize levelling and headroom of the model d02 for different
applications in analogue or digital mode.
For a digital mastering and transmission the output level should be the
maximum, i.e. the digital reference level should be 0dBFS.
When working with analog inputs it is very important not to overload the A/D
convertor (ADC), in order to ensure that the ADC always provides accurate
linear conversion of the analogue input signal to the digital audio signal which
is used for internal processing.
The analog input gain of the d02 should be set so that the maximum possible
studio output level which will occur in practice must not overload the A/D
converter.
When using the analogue output the analogue output gain following the digital
to analogue converter must also be adjusted so that the internal digital
reference level (maximum digital level which can be output by the digital limiter)
corresponds to the maximum analogue level desired for the recorder or
transmission line. Input a continuous signal such as a tone which is large
enough for the limiter to start to operate and for the maximum output level to be
output. The level on the d02 output level meter should correspond to the
internal digital reference level which was set. Then adjust the analogue output
gain to get the desired maximum analogue output level.
The calibration of the reference level should meet the maximum level of the
transmission line or the transmitter. The internal reference level (limiter
maximum output level) is always the absolute maximum level which the d02 will
output.
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