@audioengr
You are talking about measuring the picoseconds worth of jitter (which does need to be in the MHz region). I am talking about doing a J-Test and finding out how the jitter will affect the passband after being reduced with a DAC, which would show up as any added noise to the waveform. It’s the same test Stereophile uses. I do not know the psec equivalent, but it is stated as worst case scenario, and when paired with even a cheap-ish DAC like the Topping D50, any jitter with using the CCA via optical was reduced to below -130dBFS, much lower than any residential noise floor.