Implications of Esoteric G-0Rb atomic clock

Jitter occurs all over the place. It is of no significance except at the real-time A/D process or the real-time D/A process, which is when the distortion takes place.

Drubin: The point that Serus and I are both making is that frequency accuracy means nothing regarding audio quality. It is used by some marketers of digital audio technologies to introduce new numbers with flying colors (they look really good on the ads). However, the point in Jitter is not whether the frequency is accurate, it is however the point whether the SAMPLES are accurate. And that's what I am trying to show in my example: samples can be way off and cause massive distortion at the D/A or A/D process but the frequency can be right on target. Frequency is a total amount of oscillations per unit time. Jitter is how much each sample is off time target each and every time. And with clocks, this can be 33 million times a second. So potentially, a clock can make 33 million little mistakes a second and still be accurate to a fraction of a second within years and years of running.

These two things must be differentiated. And it is important to understand that Bach sounds great, whether the music is tuned to A=440 Hz or A=440.2 Hz. Nobody, not even Bach himself, would ever notice the difference. But I think it's safe to say he wouldn't have liked Jitter.

Liudas

JH's point regarding frequency is that a crystal clock is subject to transient fluctuations in output frequency caused by power supply variations & ripple, whereas the output frequency of a rubidium clock is inherently stable. He states that a transient variation in clock output frequency is "the very definition of jitter." Timing errors in the clock translate directly into a misshapen waveform and amplitude errors in the reconstructed analog signal, as well as introduction of spurious sideband frequencies unrelated harmonically to the original signal.

While I accept the benefits of ultra low-jitter clocks, I wonder whether some jitter in clock frequency is reintroduced in the clock-link cables that connect the G-ORb to the transport & DAC.

Do you really think jitter is the only reason for awful digital sound? The P-01 transport has very low jitter but still benefits from the Rubidium clock. There are other transport that have more jitter but sound as musical and with the same detail resolution as the P-01.

Chris

The P-01 transport has very low jitter but still benefits from the Rubidium clock.

I wonder whether some jitter in clock frequency is reintroduced in the clock-link cables that connect the G-ORb to the transport & DAC.

In digital, distance is very important. If a P-01 transport sounds better using an outboard clock, it speaks volumes about the low quality of the internal clock of that unit. The best scenario is when the low jitter clock is running the whole show at the very DAC chip. This way, data reclocking can be done right before conversion. If ever there is a better sound from using an external clock vs. an internal clock, it proves that the internal clock is of poor quality. Think about all the RCA and BNC connectors on the market. Think about all the digital cables. Why do they exist? Think about Eichmann, WBT, small metal contacts, 75 Ohm impedance plugs, balanced AES/EBU format, etc. etc. All of these differences are audible because Jitter is the result of a pulsating high frequency clock signal interacting with reflections as well as intermodulation with other induced ambient electromagnetic fields.

The aether is a chaotic sea of electromagnetic fluctuations going in every possible direction and at all possible frequencies. Just try to introduce a single frequency through this electromagnetic chaos without it even touching another airborne frequency -- and you will see that this is nearly impossible due to inductance and intermodulation. Therefore, shielding is of utmost importance.

Liudas