Disc Players

Thirty-five years ago when CD was in its infancy, and key components were very costly, it was not unusual for manufacturers of budget players to use a 'ceramic resonator' instead of a crystal oscillator in its master clock. Nowadays crystal oscillators are very affordable, offering a precise frequency – typically ±50ppm – by which, in particular, data is clocked into the DAC chip. Common native frequencies include 16.9344MHz and 24.576MHz which are integer multiples of audio's 44.1kHz, 88.2kHz... and 48kHz, 96kHz... base sample rates.

However, Stéphane Even, Neodino's head honcho, believes the possibility of a crystal's susceptibility to microphony renders it less suitable for the role than a tuned LC resonator circuit. Tuned to 25MHz here, the absolute frequency accuracy of this clock is still off by +616ppm. The Red Book CD standard is ±200ppm, although a fixed frequency error is less important than stability, because it's the latter that can bring jitter to the D/A conversion process. PM