Proceed CDP - Manual (Page 10)

10
Special Design Features
Congratulations on your purchase of the CDP Compact Disc Processor. The Mad-
rigal design team is confident you will enjoy the outstanding performance of the
CDP for many years. In case you are interested in technical details, what follows
is a brief outline of some of the key technologies in your new CD player.
Transport Design The first portion of any CD player it its transport: the mechanism by which infor-
mation is recovered from the disc itself and made ready for conversion to analog.
The characteristics of an outstanding CD transport are simple to define: it must
recover the correct data from the disc, and deliver it to the digital processor por-
tion of the CD player without any timing errors (sometimes called “jitter”). As
simple as this sounds, achieving it in reality has been extremely difficult—as evi-
denced by the significant sonic differences between various CD transports.
Conventional CD transport design depends on the quality of the oscillator used
to control the rate at which the disc itself spins. This oscillator exists in an ex-
tremely “noisy” electrical environment close to the motor that spins the disc. The
electrical noise introduces timing errors in the delivery of the digital signal that
have come to be known as “jitter.” Subsequent handling of the digital audio sig-
nal in traditional transport designs cannot improve upon this “jittery” signal, lack-
ing a better reference. To the contrary, the various stages of signal processing be-
tween the laser pickup and the final output can only contribute additional jitter of
their own.
The Proceed CDP leaps beyond conventional digital audio technology by em-
ploying a proprietary, closed-loop jitter-reduction system in conjunction with a
double speed
CD - ROM drive. Using a custom-made crystal oscillator with better
than five part-per-million accuracy, the digital signal is reclocked immediately be-
fore being sent to the digital to analog converters, eliminating transport-related
jitter from the digital audio signal. This same crystal oscillator controls the all-digi-
tal servo used to control the rate at which the disc spins, and the digital to analog
conversion process.
In effect, the design of the CDP turns the accepted status quo on its head. By
placing the all-important reference clock immediately prior to digital to analog
conversion, and slaving both the mechanical subassemblies and the digital to ana-
log converters to it rather than the other way around, the signal presented to the
outputs of the CDP is virtually uncontaminated by jitter. The sonic advantages of
this design are immediately apparent in the clarity, warmth and stunning dynamic
contrasts exhibited by the CDP.
Digital Servo Control The laser mechanism used in the CDP uses all digital servo controls of its opera-
tions. Critical functions such as focus and tracking are handled completely in the
digital domain with mathematical precision. Whereas conventional, analog servos
require periodic realignments for optimum performance (to compensate for the
aging of various analog components), a digital servo remains stable over time,
never needing readjustment under normal conditions.
Input/Output Versatility The CDP incorporates two digital inputs, allowing two external digital sources
such as a laserdisc player and a digital recorder to benefit from the excellent digi-