8-28
10 July 1998
numbers between 16 and 24 bits, inclusive. The bit level of the dither
signal should be set to the bit resolution of the destination for the
data. The resulting dither signal will have an amplitude equal to ±1.0
quantization level (peak-to-peak) at the selected Bit Level.
Using the examples, the bit level for the dither signal should be set to
20 bits when the data are destined for the 20-bit D/A converters, and
to 16 bits when the data are destined for the DAT recorder.
Dither Signal Characteristics
The dither signal used in the ISP-100 has a highpass spectral shape
for reduced audibility. It is characterized by approximately a +6 dB/
octave slope in the audio band.
The dither signal used in the ISP-100 has a triangular probability
density function (TPDF) for the minimization of noise modulation
effects.
Bypass
Bypassing dither results in no dither whatsoever being added to the
signal. This is different than setting the dither to the 24th bit level.
Dither Bit Level
To change settings, click on the arrow next to the number in the text
box. A selection list will appear. The list may or may not be
scrollable. To make a selection click on the desired entry.
Bypass Control (master)
This button determines if the component is in the processing chain. If
the LED on the button is gray, then the component is inserted into
the signal processing chain. If the LED is red, then the component is
bypassed in the signal processing chain. A bypassed component will
be colored red in the QuickMAP.