18
FUNCTIONAL DESCRIPTION
After switching the power on, the
digital dynamics processor
d02
automatically chooses the settings used before the power
was turned off.
All parameters used, e.g. input, preset, gain, compressor,
expander and display, are stored and re-applied.
The only
exception is the limiter which, as a safety function, is always activated
when the power is switched on.
4
Power-on Setting
The device is capable of processing digital audio signals as well
as analog audio signals. The unit accepts an AES/EBU format
digital audio signal. In the case of a digital audio input signal
being processed the internal sampling frequency of the unit is
automatically synchronised to that of the digital input signal.
The sampling frequency may be any frequency in the range
30KHz to 50KHz. The d02 directly measures the actual
sampling frequency of the AES/EBU input signal with a
frequency counter. It does not rely on the indicated sampling
frequency of the AES/EBU input signal, which is contained in
the signals "channel status" data, being correct.
Digital input signals
If the measured input signal sampling frequency is one of the
standard frequencies (32kHz, 44.1kHz or 48kHz) then a
corrresponding LED will light yellow in the input section on the
units front panel. Continuous lighting yellow of an LED also
indicates that the digital input signal is a valid AES/EBU
digital audio signal which the d02 can synchronise to properly.
Digital input signals
- sample frequency
If AES digital input is selected but the d02 can not
synchronise properly to a supplied AES/EBU input signal (for
example because there is no valid input signal or because the
input signal has a sampling frequency outside the
admissable tolerance range) then all three "sampling
frequency" LED's in the input section of the d02 front panel will
flash red. Digital audio input signals in the standard AES/EBU
format pass from the AES/EBU input connector through a
transformer (as specified by the AES/EBU standard) to the
AES/EBU interface circuitry. The AES/EBU input circuitry
derives the d02's internal sampling frequency from the
AES/EBU input signal and seperates the audio data in the
AES/EBU bit stream from additional control bits, such as
channel status data bits (C-bit) and user bits (U-bit). The audio
sample data is converted from AES/EBU format into the
Digital input signals
- AES/EBU
