Alpine F#1 Status CDA 7990R User Manual page 4

Noise from various points of the circuit is restricted to the
ultimate level to reproduce unprecedented "quietude"
Black-finish DP/ST mechanism & copper-plated black-finish chassis for less noise
effects, electric distortion, and data reading deterioration.
Reflections of the laser from the CD surface can bounce into the laser reading head, causing transition
errors when the digital bits change between 0 and 1 ("jitter"). These transition errors decode as low
level noise and distortion. To eliminate such possibilities, the DP/ST mechanisms are all painted
black, including the inner faces and circuit boards. This reduces the optical noise and achieves an
improved S/N ratio that can be easily recognized in the reproduced sounds.
Reducing noise by lowering impedance of power supply system: four-layer PCB with
STAR Circuit
A copper through-hole four-layered PCB allows ideal patterning and part layout for minimal pickup of
radiated electromagnetic noise. Furthermore, by doubling the thickness of the copper foil to 70mm, a
reduction of noise is achieved, along with lower impedance of the power supply system. One layer out
of four is the ground and Alpine's unique STAR (Signal Transit for Accurate Response) Circuit is
mounted in order to reduce interference . By inserting the ground layer, a reduction in interference and
ideal part layout were targeted.
Shield FPC shuts out noise
Flexible Printed Circuit+j
The FPC, sandwiched between two shield layers, rejects noise effects from the power line and master
clock line.
Plenty of carefully selected "high-quality parts" supporting the high performance of
DAC
Includes non-metal carbon film resistors (for high-quality audio) with no magnetostriction, high-
quality sound custom slave-less electrolytic capacitors preventing electricity charge on the capacitor
coating that may affect capacitor characteristics adversely, hand-picked high-performance op amps,
etc. The unrestricted use of these noise/signal distortion-resistant devices achieves a three-times-
higher S/N ratio.
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