How critical is the clock frequency

The stability of the clock is very important in audio applications. Instability can lead to increased distortion and noise.

You can quantify clock stability essentially measured using two metrics:

Fequency drift - In other words, how close is the mean frequency of the clock to the desired rate and how much does it drift from the ideal? If the actual frequency of the clock is 1% different than the desired rate, then the result is a frequency shift on the actual audio signal. For music, this would be audible as a shift in pitch. If the frequency drifts back and forth quickly, then you essentially end up with a vibrato effect. The audibility of this of course is subjective, but in any event it's frequency distortion.

Jitter - In other words, how much does the clock edge vary from the ideal timing? If jitter is large, a significant amount of distortion is added to the signal. This degrades the effective noise floor of the DSP or converter. Even small amounts of jitter in the tens of nanoseconds can be audible.

This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

Thank you,
EZ Admin