Abbingdon Music Research CD-77 Reference Class - Manual (Page 17)

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3.12 kHz/OptiSample® (RC-77 only)
The CD-77 Compact Disk Processor offers 6 user-selectable methods of Sampling that can be cycled through
during playback by pressing the kHz/OptiSample® button (RC10) on the RC-77. The sampling options are:
a. Digital Master I – this mode directly takes the data extracted from the CD and re-clocked to generate the music
signal. Due to the complete lack of digital or analogue filtering, the treble frequencies are slightly rolled off, making
the sound somewhat soft and laid-back. For the same reason, the mid-range and below is very natural and realistic.
The reproduction of impulses is undistorted. This mode often helps to ‘tame’ overly-bright recordings.
b. Digital Master II (default) – this mode is identical to Digital Master I but complements this with a special
analogue filter which corrects the roll-off in the treble frequencies. As a result, the tonality is more accurate in the
treble. We therefore recommend this mode as the benchmark with which to enjoy music.
c. Oversampling 2x – this mode engages the Digital Filter with an oversampling factor of 2, thus performing the
least digital processing possible (except for no digital processing). The original data from the CD is in effect discard-
ed and re-placed with a re-computed version. This new version of the music is mainly linearly scaled up using a
whole number as scaling factor and resolution/edge enhanced. The sonic result of oversampling mirrors those of
resolution enhancement in digital photographs: more apparent detail is noticeable. However, impulse reproduction is
slightly distorted, leading often to a slight perception of an edginess or graininess.
d. Oversampling 4x – this mode engages the Digital Filter with an oversampling factor of 4, performing quite a
large degree of digital manipulation. The original data from the CD is in effect discarded and re-placed with a re-
calculated version. This new version of the music is mainly linearly scaled up using a whole number as scaling factor
and resolution/edge enhanced. The sonic result of Oversampling 4x is similar to that of Oversampling 2x; except
more accentuated.
Digital Master II is
the benchmark for
playback