Specifications

2.12
Applications Manual
© 2003-2005 Prism Media Products Ltd
Revision 1.11Prism Sound dScope Series III
3.2.3.4 Input for full-scale amplitude
Applies to:
EUTs with analogue inputs.
Aim:
To determine the maximum input amplitude before digital clipping with normal device settings.
Method
The input gain controls are set to the reference position supplied by manufacturer or to the normal
operating position if no reference position is specified. Other controls should be adjusted to minimise
the potential for overload in the output circuitry.
The measurement is made using a 997Hz sinusoidal stimulus.
If the measurement is to be made at the digital output of the
EUT
, and if digital
full-scale amplitude
can be reached, then the measurement is made by adjusting the amplitude of the test signal until
digital full-scale is just achieved at the output.
If the measurement is to be made at the analogue output of the EUT, or if the digital output is used
but digital full-scale amplitude cannot be achieved, then the measurement is made by adjusting the
amplitude of the test signal until 1% THD+N or 0.3dB compression occurs. The result is defined to be
0.5dB below this amplitude.
The result is displayed for both channels in dBu and V (RMS).
See also:
Level Search Routines
for fault finding with this test.
3.2.3.5 Maximum input amplitude
Applies to:
EUTs with analogue inputs.
Aim:
To determine the maximum input amplitude for correct operation.
Method
The input gain controls are set so as to allow the maximum possible input amplitude to be
accommodated. Other controls should be adjusted to minimise the potential for overload in the output
circuitry.
The measurement is made using a 997Hz sinusoidal stimulus.
If the measurement is to be made at the digital output of the
EUT
, and if digital
full-scale amplitude
can be reached, then the measurement is made by adjusting the amplitude of the test signal until
digital full-scale is just achieved at the output.
If the measurement is to be made at the analogue output of the EUT, or if the digital output is used
but digital full-scale amplitude cannot be achieved, then the measurement is made by adjusting the
amplitude of the test signal until 1% THD+N or 0.3dB compression occurs.
The result is displayed for both channels in dBu and V (RMS).
See also:
Level Search Routines
for fault finding with this test.