How do you read the measurements?
Contents
Jitter is a complex matter. In fact, there are several types of jitter. And each form has a different “origin”. It is very nicely explained here. Hans Beekhuyzen has also explained jitter and its effects excellently on his Youtube channel.
We can divide jitter – or Total Jitter in jargon – into Derterministic or ‘Bound’ Jitter (DJ) and Unbound Jitter (RMS). Deterministic jitter (also called peak/peak) is again broken down into other forms. Consider Periodic (PJ) and data dependend (DDJ) jitter, where data dependend is again split into Duty Cycle Distortion and Intersymbol Interference.
Hi Jaap,
really interesting test!
What surprises me is that there is no clear correlation between phase noise and jitter – since they are just two sides of the same coin.
I believe that the Pura the AMMONITE switches perform well because they have better phase noise in the Ethernet signal by using the OXCO clocks. That would at least be a coherent explanation that would also agree with John Swenson’s thesis. Then we would have two things affecting the sound: common mode noise and phase noise.
Have you found a dependency regarding the frequency range of the common mode noise to worsen the streamer clock – I would be interested. I could not clearly assign this in the measurements.
Best regards,
Eric
Hi Jaap,
really interesting test!
What surprises me is that there is no clear correlation between phase noise and jitter – since they are just two sides of the same coin.
I believe that the Pura the AMMONITE switches perform well because they have better phase noise in the Ethernet signal by using the OXCO clocks. That would at least be a coherent explanation that would also agree with John Swenson’s thesis. Then we would have two things affecting the sound: common mode noise and phase noise.
Have you found a dependency regarding the frequency range of the common mode noise to worsen the streamer clock – I would be interested. I could not clearly assign this in the measurements.
Best regards,
Eric
When you compared switches, does noise peaks appeared the same frequency points on each switches and how big was the general noise floor levels on them? It would be nice to see spectrum analyzer screen shots from each switches how then behaved.
If you login via Patreon, you can see all the measurements.
When you compared switches, does noise peaks appeared the same frequency points on each switches and how big was the general noise floor levels on them? It would be nice to see spectrum analyzer screen shots from each switches how then behaved.
If you login via Patreon, you can see all the measurements.