Implications of Esoteric G-0Rb atomic clock

WARNING: There is a lot of marketing going on here. Please consider the fact that frequency stability is not the issue of Jitter! The issue of Jitter and how that distorts audio at the A/D process is a problem of each sample coming at slightly the wrong time. Frequency stability has nothing to do with this. A small example:

The numbers 3,3,3,3,3,3,3,3 average out as the number 3.

The numbers 2,4,2,4,2,4,2,4 average out as the number 3. (This is as simple as 24 / 8 = 3).

The numbers 1,5,1,5,1,5,1,5 also average out as the number. (This is as simple as 24 / 8 = 3).

However, were these Jitter deviations from perfect timing (fluctuations from the ideal value, which was in this example, 3) you would have had worse and worse audio going down the line.

The marketers of all three pieces of equipment in the above example could easily all have said the same thing without lying: "Our Clock is so stable that you can play it for 3 million years and it will never be off by more than a fraction of a second".

Please notice the significance of this. Be aware of the logical trap that this "frequency stability" terminology is putting people into!

Liudas

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

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

Audiofeil: "I think the manufacturer in this discussion is suffering from what Freud called 'Product Envy'"

I choose to dissemintate what I hold to be knowledge at opporunities when my conscience is troubled, for I have a general disposition to side with defending any truth when I suspect disinformation being spread. This reflects a type of world view which I attempt to consciously carry. You may choose to examine further any subconscience aspects of this behavior, but please be aware that in the human science of psychology, it is by now generally known that one tends to notice upfront those aspects of others which are in truth deeply embedded in our own subconscious selves.

Liudas

Lapaix, having worked for several years trying to get the ultimate jitter-free sound from a computer source, I can say that it remains better, audibly better, to play files from USB RAM rather than from hard drives. Yes, hard drives are read in packets, and yes, they are buffered extensively throughout a computer system's busses and operating system and playback software and hardware drivers, but the sound remains better from a USB RAM. And this remains worse than the sound achieved when slaving a CD player to a master dac synchronously. The ultimate point in buffering is not the size of the buffer, but the quality of the clock signal. And the quality of the clock signal depends ultimately on all of the surrounding factors including: its own power supply, the radiating ambient high frequency EM signals from other quartzes and other busses, vibrations (hard disks vibrate), and many other things knowns and possibly unknown. THere are several forums on the internet where people have been discussing computer audio for years and some have reached a very high end sound this way. However, once you put all the solutions up to the line and really compare, it remains improbable that merely enlarging a buffer will take away all the digital nasties. Another way of looking at it is that a CD already is a buffer. It is the buffer that is holding the DATA which was recorded at the finite moments of A/D sampling (during the recording). Whether CD, DVD, hard disk, ram, or anything else, the playback depends on the quality of clocking it.