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Implications of Esoteric G-0Rb atomic clock

The latest TAS (March 2008) has an excellent piece by Robert Harley: a review of the Esoteric G-0Rb Master Clock Generator, with sidebars on the history and significance of jitter. This Esoteric unit employs an atomic clock (using rubidium) to take timing precision to a new level, at least for consumer gear. It's a good read, I recommend it.

If I am reading all of this correctly, I reach the following conclusions:

(1) Jitter is more important sonically than we might have thought

(2) Better jitter reduction at the A-D side of things will yield significant benefits, which means we can look forward to another of round remasters (of analog tapes) once atomic clock solutions make it into mastering labs

(3) All of the Superclocks, claims of vanishingly low jitter, reclocking DACs -- all of this stuff that's out there now, while probably heading in the right direction, still falls fall short of what's possible and needed if we are to get the best out of digital and fully realize its promise.

(4) We can expect to see atomic clocks in our future DACs and CDPs. Really?

Am I drawing the right conclusions?
Ag insider logo xs@2xdrubin
seandtaylor99
1,262 posts
 
Ehider ... you don't need USB, you just need a buffering and reclocking DAC, like the Lavry 924. A relatively small RAM buffer will allow for any drift between the transport clock and the DAC master clock.

Of course, the more stable the DAC master clock the better. This may be where a rubidium type clock is useful .... I don't know.

I'm not sure where current technology is with respect to the relative influence of clock imperfections versus DAC non-linearity (both are probably an order of magnitude better than current speaker technology).

One last thought ... it's true that ADC clocks are equally important, and therefore a better ADC clock will lead to a better remaster. However, the implication is that all early digital recordings (ADAT) are forever unrecoverably distorted by the relatively poor clocks used at the time.
dazzdax
599 posts
 
Sean, is it possible once jitter is introduced into a specific recording to remaster this recording in such a way that the jitter could be eliminated? If this is not possible, why not? Are those early digital recordings sounding bad because of the high jitter content? There are also oldskool digital recordings (from 1980/1981/1982) that sound great, how could you explain that? Pure luck?

Chris
ehider
286 posts
 
Perhaps a re-iteration of my explanation is in order. All SPDIF digital connections (read "traditional") cannot sonically compete with a properly designed USB Dac (being driven by a hardrive). Even if the traditional digital connection is being "buffered" or "re-clocking" the data, etc. The traditional digital connection scheme was seriously flawed from the get-go. UBER designed "re-clockers" or "buffering" schemes are only band-aids. They work to a point, but still don't quite give us the true analog purity we were all hoping to achieve. Closer yes. Perfection, not by a country mile! Too many of these "band-aids" are damn expensive at that. Of course the proof is in the pudding. The recent USB Dac I heard comes so close to sounding like analog that I was shocked that ANY digital could sound this good. No other digital scheme I've heard comes nearly as close (and I've heard way too many to count).
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drubin OP
3,275 posts
 
Ehider, I'm reluctant to open this can of worms, but have you heard the Nova Physics Memory Player? If so, how does it compare to the USB DAC you heard?
seandtaylor99
1,262 posts
 
Ehider ... USB DACs are RAM buffered because USB does not stream the data at the bit rate required by the DAC.

Since it's possible to buffer for USB then it's possible to do the exact same for SPDIF.

A more likely explanation is that the USB DAC you heard happened to be a better designed DAC (or more to your taste) than any other SPDIF DAC you'd previously heard.
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