Mirage Digital Evolution
AEV Broadcast Srl via della Tecnica 33, 40050 Argelato Bologna ITALY
www.aev.eu [email protected]
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3
AUDIO Input & Output
3.1 Connection cables
For input / output connections it is recommended to always use a good quality soft cable with good
shielding.
It is also necessary to check the correct functioning of the earthing system and that in the audio
connections between the GROUND and CHASSIS GROUND devices they are separated to avoid annoying
buzzing.
3.2 Analog Input/Output
The analog XLR input are electronically balanced with input 10 KΩ impedance.
The male XLR analog outputs are active with 47 Ω impedance.
The output range varies from -12 dBm to +12 dBm with a 1 dB step.
The level control of the analog inputs and outputs is implemented via software on the ANALOG INPUT and
ANALOG OUTPUT menus.
3.3 Digital Input AES/EBU
The AES / EBU digital input on female XLR can vary from -12 dBm to +12 dBm in 1 dB steps.
The input level control is implemented via software on the DIGITAL AES / EBU INPUT and DIGITAL
OUTPUT menus.
3.4 Digital Optical Input
The optical digital input is connected to the dedicated fiber optic connector
The input signal range varies from -12 dBm to +12 dBm in 1 dB steps.
The input level control is implemented via software on the DIGITAL OPTICAL INPUT menus.
3.5 Digital Outputs
The AES/EBU digital output is supplied on a male XLR connector, the optical digital input is connected to
the dedicated fiber optic connector.
The output range varies from -12 dBm to +12 dBm with a 1 dB step.
The level control of the digital outputs is implemented via software on the DIGITAL OUTPUT menus.
The selection of the sample rate of the digital signal is realized via software on the DIGITAL OUTPUT menus.
The value of the output level and of the digital signal network sample is unique for the AES/EBU signal and
for the optical signal.
4 Operation
4.1
Introduction to processing
In any sound source it is possible to define the mean value and the peak value.
In the mean value it contains much of the power and is therefore the most significant part of the
signal compared to the peak value that has contributions in terms of extremely low power.
Unfortunately, however, in the FM transmission, the maximum deviation of 75 KHz is determined by
the peak value; So you are forced to work with a low level level producing a non-incisive sound level.
To increase the sound level, reduce the peak-to-medium ratio; If the peaks are reduced, the average
level can be increased within the permissible modulation limits.
These operations can be achieved with signal limitation and expansion processes.
Mirage Dig Evo performs this processing on 4 different bands using adjustable threshold compression
circuits.
Clipping is a more decisive control applied to that part of the signal that can not be compressed; This
operation is always necessary to ensure maximum deviation of 75 KHz. Cutting does not produce
audible side effects if it is carried out in moderation, in reverse, if it is used excessively, it may give
rise to more or less annoying distortion.
A compression level that exceeds -16 dB (eg -18, - 20 etc.) continuously indicates a probable error
setting of control parameters
