HP N31.5 manual Special Design Features

A New Generation

Digital Servo Control

Output Versatility

Special Design Features

Congratulations on your purchase of the Nº31.5 Reference CD Transport. The Madrigal design team is confident you will enjoy the outstanding performance of the Nº31.5 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 transport.

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 with- out any timing errors (sometimes called “jitter”). As simple as this sounds, achiev- ing it in reality has been extremely difficult—as evidenced 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 Mark Levinson Nº31.5 leaps beyond conventional digital audio technology by employing a proprietary, closed-loop jitter-reduction system in conjunction with a double speed CD-ROMdrive. Using a custom-made, mechanically and electrically isolated crystal oscillator as a reference, the digital signal is reclocked immediately before the output, eliminating transport-related jitter from the digital audio signal. This same five part-per-million crystal oscillator controls the all-digital servo used to control the rate at which the disc spins.

In effect, the design of the Nº31.5 turns the accepted status quo on its head. By placing the all-important reference clock in the final stage of the transport’s out- put section, and slaving the mechanical subassemblies to it rather than the other way around, the signal presented to the outputs of the Nº31.5 is uncontaminated by electrically- or mechanically-induced jitter. The sonic advantages of this design are immediately apparent in the clarity, warmth and stunning dynamic contrasts exhibited by the Nº31.5.

The laser mechanism used in the Nº31.5 uses all an digital servo control. Critical functions such as focus and tracking are handled completely in the digital do- main, with mathematical precision. Whereas conventional, analog servos may re- quire periodic realignment for optimum performance (to compensate for the ag- ing of various analog components), a digital servo remains stable over time, never needing readjustment under normal conditions.

The Nº31.5 supports a wide variety of digital output configurations to ensure op- timal performance with a wide range of digital audio processors. A new comple- mentary driver for the balanced AES/EBU electrical output delivers outstanding performance to the high quality XLR connector. Single-ended S/PDIF electrical output is provided via an RCA connector, and the ST optical output uses a high-

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