Antex Electronics SX-5e - Manual (Page 62)

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Digital-to-analog conversion (used in playback) is the exact oppo-
site of the analog-to digital conversion process and is illustrated in
Figure 21.
In digital-to-analog conversion, the PCM bitstream is converted at
the sampling frequency to a continuously changing series of
quantization levels which are individual "steps" of discrete voltage
equal to the quantization levels in the analog-to-digital process.
The shape of this continuously changing stream of quantization
levels approximates the shape of the original wave. This is shown
in the top half of Figure 21. This signal is then passed through a
low-pass filter, which removes the digital "switching noise." The
end result, shown in the bottom half of Figure 21 is an analog out-
put signal whose waveshape is a very close approximation of the
original analog input signal.
Figure 21. Digital-to-Analog