DCS Vivaldi

[opus111]

AES probably wants you to pay for their standard to get that answer! One website I saw selling a master clock for studio use claimed Class 1 and mentioned their figures were 0.7ppm over 12 months.

 

[DonH50]

Too true.

Man that's impressive, but I have to keep reminding myself these are MHz clocks, not GHz...

 

[Phelonious Ponk]

It's fun to hang out with the engineers when they're making fun of marketing copy, but soon, they go back to speaking in tongues.

Tim

 

[DonH50]

Last time I went to the DMV they had me take a number. It was sqrt(-1).

 

[opus111]

When they speak in strange tongues that's when you, as marketing bod have to insist they translate into simpleton speak. It can always be done but many engineers will just go back to their oscilloscope coz communication isn't what drives them.

What I've figured about marketing, as an gamekeeper-turned-poacher is that customers really want stories. Intensely hyperbolic trumpet blasts like dCS is using don't satisfy, its junk marketing with no nutritional value. Some gossip about how a product came to be the way it is, with snippets of engineering personality thrown in works much better.

<edit> Having said that though, given that this product isn't based on sound engineering, and given that the potential customers will probably be gullible enough to swallow all the guff, perhaps dCS has gauged their target market perfectly.

 

[DonH50]

many engineers will just go back to their oscilloscope coz communication isn't what drives them.

Intensely hyperbolic trumpet blasts... don't satisfy.

Oooh, pretty pictures!

And, I resemble and deny that remark! Which reminds me, need to go practice offertory for next week.

Anybody on WBF in line to hear the DCS Vivaldi?

 

[opus111]

Last time I went to the DMV they had me take a number. It was sqrt(-1).

What's the DMV?

I reckon they'd have to ask you a question first - 'Engineer or mathematician?' so as to know whether you would receive 'i' or 'j'.

 

[Bruce B]

I'm curious Bruce - which (if any) DACs have you heard where it does improve the sound?

Nothing in the last 4-5yr.... there were 2 that sounded better IMHO... A Genex 9048 and a dCS 905/955 combo... both long since discontinued.

 

[LL21]

Google found me this result in Google books (after I'd filtered out all the hits to dCS marketing materials) : http://books.google.com/books?id=y0...onepage&q=aes-11 grade 1 master clock&f=false

The short answer is its about long term stability, which is so not an issue in audio as crystals are all way better than mains frequency stability over the short term. Grade 1 is 1ppm.

@Tim - now you're just getting greedy

Opus, Don and Bruce - Thanks to all of you! Good reading!!!

 

[LL21]

What's the DMV?

I reckon they'd have to ask you a question first - 'Engineer or mathematician?' so as to know whether you would receive 'i' or 'j'.

DMV is Department of Motor Vehicles...local government agency where people have to stand in line to register their car and/or renew their driver's license.

 

[opus111]

Ah, thanks Lloyd, I figured it was one of those places where you press a button for a numbered ticket when you arrive and then eventually your number comes up on an LED display telling you which booth to head for. They do that in the bank here where I go to pay my bills every two months - listening to repeated announcements helps my listening skills in Chinese

 

[AudioExplorations]

Opus, your technical opinion is much appreciated, it is triggering some great discussion !

Any thoughts on the external upsampler?

 

[Phelonious Ponk]

'it improves on an already spectacular sound and takes it into an entirely new domain.' - pass me the sick bag please.?

Like I said... if it improves the sound, then the DAC is poorly designed.

I'm curious Bruce - which (if any) DACs have you heard where it does improve the sound?

Engineering translation please? The master clock is not supposed to affect the sound of the DAC? So what does improve the sound of a DAC?

Tim

 

[opus111]

Opus, your technical opinion is much appreciated, it is triggering some great discussion !

Thanks for the encouragement.

Any thoughts on the external upsampler?

From reading the blurb it seems it performs two main functions - a media 'hub' and sample rate/format conversion. The former seems to me to be valuable, the latter not.

I'm of the view that the data in the recording is to be tinkered with as little as possible, because all math operations on digital data increase the word length and require eventual rounding. Meaning there's always going to be some loss of information, even though that loss can be kept small with long enough digital words. Upsampling as a general process isn't necessary and can only in the limit be neutral,l never beneficial.

Where upsampling's losses can be outweighed by gains is if the particular DAC chipset being used has inherent drawbacks when operating at the lower frequency which are ameliorated by running at a faster rate. Here I don't believe that to be the case or else the upsampling function would be put inside the DAC to ensure the DAC is always operating at its optimal performance. In general running a DAC faster degrades its performance because with more clock edges per unit time the DAC is spending a larger proportion of its time slewing between samples. I doubt here that dCS change the clock rate of the DAC significantly though when it deals with different input rates because its already oversampled by a large degree - more likely they just adjust the oversampling ratio.

 

[opus111]

The master clock is not supposed to affect the sound of the DAC? So what does improve the sound of a DAC?

If the engineering's been done well, nothing. If you want to improve the sound of a DAC, buy a better DAC or mod the one you have. Bruce is pointing out that if a DAC's clocking performance is improved by connecting to an external clock its a sign that something's seriously wrong with its internal clock in terms of jitter. This is because an externally fed-in clock isn't going to have the best jitter because of its physical distance. When a DAC receives an external clock signal it uses that one and disregards its internal one (something of a simplification for non-engineering types ).

 

[AudioExplorations]

Opus, very interesting stuff. I share the same theoretical engineering beliefs RE the clock being physically next to the DAC chip and upsampling. To use a simple analogy you cannot zoom into a 1 megapixel image and extract information that is not there like you see done in the movies : ).

I wonder what type of oscillators are used within the Vivaldi DAC, have you seen any information on this?

What are your thoughts on the MSB IV DAC with it's Femtosecond Galaxy Clock? This is arguably the most advanced 'on-board' clock today.

 

[opus111]

Opus, very interesting stuff. I share the same theoretical engineering beliefs RE the clock being physically next to the DAC chip and upsampling. To use a simple analogy you cannot zoom into a 1 megapixel image and extract information that is not there like you see done in the movies : ).

Yes - fair analogy.

I wonder what type of oscillators are used within the Vivaldi DAC, have you seen any information on this?

I am not at all up to speed on different kinds of clocks. That's largely because in my ongoing DAC developments there's been plenty of 'low hanging fruit' other than paying attention to jitter.

What are your thoughts on the MSB IV DAC with it's Femtosecond Galaxy Clock? This is arguably the most advanced 'on-board' clock today.

My gut tells me its pure marketing. But then as I just said, I'm not someone who's (yet) been won over to the wonders of lower jitter. So its a provisional conclusion. The whole subject of jitter in digital seems to me the area in the high-end where the most smoke is being blown.

 

[FrantzM]

If the engineering's been done well, nothing. If you want to improve the sound of a DAC, buy a better DAC or mod the one you have. Bruce is pointing out that if a DAC's clocking performance is improved by connecting to an external clock its a sign that something's seriously wrong with its internal clock in terms of jitter. This is because an externally fed-in clock isn't going to have the best jitter because of its physical distance. When a DAC receives an external clock signal it uses that one and disregards its internal one (something of a simplification for non-engineering types ).

That is also my point of view, the physical distance and the cabling associated with the clock/DAC interfaces is bound to reduce performance. This blatant marketing and, sadly, it will bear its fruits. It's a stack after all and you will have the whole cabling make a "huge" difference issue, by using different cables you can bring more "synergy" to the system , etc..

Call it by any name you please , naive will come to mind, this saddens when there is real progress to be made in there and at more than reasonable prices and this won't stop the manufacturers from offering more smoke and ever higher priced digital gear .. It will help if the company has some real engineering and professional music background. It is no surprise then that Weiss and DcS are at the top of the digital high price heap... Oh Well !!

 

[Phelonious Ponk]

(something of a simplification for non-engineering types

I'll take all the simplification I can get, thanks. Even at that, my lips are moving as I read your posts, so allow me to leap to a grossly over-simplified conclusion for you to debunk: You seem to be of the belief (and there is admittedly much assumption going on here), that simpler is better -- no external re-clocking, no oversampling (unless it is integrated into the DAC chip itself to compensate for performance), no nonsense. A fair assessment? So would the theoretical ideal would be?.... an SOTA DAC chip + ? In other words...

If you want to improve the sound of a DAC, buy a better DAC

In your view, what constitutes "a better DAC?"

in my ongoing DAC developments there's been plenty of 'low hanging fruit' other than paying attention to jitter.

I'm not someone who's (yet) been won over to the wonders of lower jitter. So its a provisional conclusion. The whole subject of jitter in digital seems to me the area in the high-end where the most smoke is being blown.

So...what does all of this mean? You think common jitter levels are low enough and don't really need further reduction? You don't think jitter is a particularly audible distortion? Clearly it is not a priority for you, while it seems to be a huge issue, maybe the biggest issue, for high-end jitter designers. What's your position?

Oh and if not "high-end," what kind of DACs do you design? Under what brands?

Tim

 

[asiufy]

First of all, I don't subscribe to the theory that "if XXX improves the sound, equipment YYY was bad to begin with".
Besides, the dCS gear is supposed to be used as "stacks". So, even though the DAC unit has an internal clock, it is supposed to be used with the external clock. The improvement by using the external clock is there by design.
Second, it's been my experience that separating each function, with dedicated power supplies, has a very positive effect on the sound quality. The gap between the Puccini+clock (2 boxes) and the Paganini (4 boxes) is monstruous. And the gap between the Paganini and any other digital gear is just as wide, IMHO.
Then, there's the fact that, by putting the clock inside the DAC, you'd still have to plug it in the other 2 pieces (transport/upsampler) if you wanted to keep them in sync. So, perhaps in dCS' view, the damage you'd do by adding more circuitry to the DAC would be worse than using the master clock in a separate box...

And one thing about volume control... Do you really think they mean you have 2v and 6v as the only options for "volume control"?


alexandre