A customer requested that I ship a Synchro-Mesh re-clocker to the measurement worshippers at audiosciencereview, so I did. Here are some measurements that they performed on it. They have their conclusions and I have mine. It's all about how you interpret the data. I never did like using a particular DAC to measure jitter of a source, because the DAC factors into it. I much prefer direct measurement. I believe that there is still very poor correlation of jitter measurements to listening tests, so we cannot say with any certainty whether one device will sound better than another based solely on measurements. It's a macro characterization at best IMO, so at high levels of granularity it is useful. I would like it to be more useful. I really appreciate them doing this however. It is always a learning experience, hopefully for them as well.
Here is the link:
https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-empirical-audio-synchro-mesh.7062/The main plot:
This compares the Gustard internal clocker with the external Synchro-Mesh reclocker. SM is the pink and the other two colors are the Gustard DAC with and without the internal PLL clocking turned on.
One observation that I will make here is that the jitter around the tone is much less with the Synchro-Mesh. You can see "skirts" on either side of the spike in the middle when the Synchro-Mesh is removed. The baseline noise level is a little higher, but this is still in the noise and I would argue not audible. The difference in the hot pink plot and both the blue and flesh-colored plots that concerns me about the Gustard is the widening of the tone spike at the bottom. I have correlated this shape to degradation in audio quality in the past. The Synchro-Mesh plot has virtually no widening at the base, no visible "skirts".
If you believe my premise that it's the correlated jitter that is more audible than random jitter, then the widening of the base of the fundamental in this plot is precisely that, jitter that is frequency modulation close to the the frequency of the fundamental. The Synchro-Mesh plot contains zero of this.
I believe the interpretation of the measurements are as important as the measurements themselves. It's important to understand what relative importance each of these factors have when correlating to human hearing. After all, this hobby is about listening to music that inspires us, not making measurements for the sake of measurements, and it is a hobby, not national security.
