Abbingdon Music Research Compact Disk Processor CD-77 - Manual (Page 29)

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The following section describes and where relevant, provides instructions to access the CD-77’s advanced
features.
3a. OptiSample®
The CD-77 Compact Disk Processor offers 6 user-selectable methods of Sampling that can be ‘cycled through’
during playback by pressing the OptiSample® button (RC10) on the RC-77. The sampling options are:
1. 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.
2. 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.
3. 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
discarded 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.
4. Oversampling 4x – this mode engages the Digital Filter with an oversampling factor of 4, performing quite
Section 3 - Advanced Features
Digital Master II
is the benchmark
for playback