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More Rob Wattisms

Purité Audio

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#1
I need someone cleverer than me ( almost everyone ) to decode this for me, to me it sounds like more BS, and an admittance that his most expensive dac isn’t immune to power supply vagaries,
Quote,
‘Yes all sources create RF noise. We have two ways of coupling RF noise - via the cables, or electromagnetically. This mode is stopped with Dave being made from a solid block of aluminium - it is extremely well screened. The mains, and the outputs are RF filtered too. On the USB, we have galvanic isolation, but that will not completely isolate Dave from the source, as it has 2pF of coupling capacitance on the galvanic isolation (all isolators have some level of coupling capacitance).

Now this coupling capacitance is important, as RF noise voltages from the source will inject a small current into Dave's ground plane - and due to the ground plane having a 0.5 ohms per square and about 1 nH inductance per square will create small internal RF voltages that is picked up by the analogue electronics which will then induce a tiny amount of IM distortion, and so noise floor modulation will increase - even though Dave has immeasurably small amounts of RF noise modulation, the small extra amount is audible.

But if you run the source from batteries, and have no ground connected to the lap-top, then there are no net currents flowing into Dave, as the isolation capacitance of the lap top to ground is much smaller than the 2 pF from the isolators; in effect you are now completely isolating the source from Dave via the direct USB connection and so no RF currents from the source can be injected into Dave's ground plane. That's why this mode sounds a bit smoother and warmer than mains powering the lap-top.

Having said all that, we are talking about very minor stuff here; it's not the icing on the cake but making sure the icing is flat to 1 micron rather than 0.1 mm...Before the galvanic isolation I used to get huge differences from sources if they were mains powered - now we are talking about a small change that is only audible on AB tests. When I listen to music I don't bother disconnecting the lap-top - only when doing serious testing.

I wait with baited breath,
Keith
 

Blumlein 88

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#2
Depends upon the audibility of 1 micron of icing. :)

I'd be more convinced if he gave me millivolts or db. We already know he claims effects 200 db down are audible.
 

amirm

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#4
now we are talking about a small change that is only audible on AB tests. When I listen to music I don't bother disconnecting the lap-top - only when doing serious testing.
Nonsense. He would flunk any such test blind. He has the same analyzer as I do. He is talking about real, measureable stuff. Measure it for heaven's sake and post that. He won't be able to do of course because he has a theory for a problem, not a real one.
 
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#5
Yes, straight out the snake oil salesman hand book, invent a problem that doesn't exist then claim your product solves this problem.
 
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#7
C’mon Keith, stop shaking the hornets nest, you know there’s not a problem present that a £1,500 pair of ferrite ladenend cables can’t fix.
 

Music1969

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#9
to me it sounds like more BS
If he was producing gear that measured averagely I'd call BS.

But he designs state of the art gear, with the measurements to boot. So maybe he knows what he's talking about?

Emphasis on maybe - I don't know because most of this stuff goes over my head. But if I constantly read about state of the art measurements with his gear, it has to count for something?


https://www.stereophile.com/content/chord-electronics-dave-da-processor-measurements

https://www.stereophile.com/content/chord-electronics-qutest-da-processor-measurements

https://www.audiosciencereview.com/...ew-and-measurements-of-chord-qutest-dac.5981/
 

amirm

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#10
But he designs state of the art gear, with the measurements to boot. So maybe he knows what he's talking about?
No, because the part about hearing differences is not engineering. It is audio science. And there, he told me direct that he doesn't believe in blind tests. You can't be more counter to everything we know about proper evaluation of audio.
 

March Audio

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#11
Imo it's not entirely bollocks, the technical bits are mostly real. The bit that's bollocks is the assertion that the immeasurable is audible, that he conflates that technical commentary into a real world audible effect. As Amir says his non scientific audibility testing methods can't justify his claims. Its just Rob Watts saying its audible. That's not evidence, that's marketing.
 

Music1969

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#12
You can't be more counter to everything we know about proper evaluation of audio.
Noted. It's a paradox because, against the backdrop of apparently poor evaluation of audio, is the state of the art measurements of his DACs...
 

amirm

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#13
Noted. It's a paradox because, against the backdrop of apparently poor evaluation of audio, is the state of the art measurements of his DACs...
It is the wash your dishes 100 times principle with him. So no harm comes out of doing more other than huge increase in cost/retail price of gear.
 

Blumlein 88

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#14
It is the wash your dishes 100 times principle with him. So no harm comes out of doing more other than huge increase in cost/retail price of gear.
This is my father's approach to things. If he designed a car to his criteria, it would never break down, be easy to fix (which was a waste because it will never break down), and that all sounds great. But it would be quadruple redundancy on everything and all of that would be overbuilt. It would weigh 42,000 pounds (19,000 kg), cost $10 million, and get 10 gallons to the mile ( 23.7 liters to the kilometer) on fuel usage. He could patiently explain scenarios where the first three overbuilt systems could fail and only with the fourth redundancy could you be assured of a good result.
 

Music1969

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#15
It is the wash your dishes 100 times principle with him. So no harm comes out of doing more other than huge increase in cost/retail price of gear.
I agree with this if we're talking Dave. But luckily Chord have something like Qutest in their lineup - not inexpensive but something more affordable and still with state of the art measurements.
 
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#16
If he was producing gear that measured averagely I'd call BS.

But he designs state of the art gear, with the measurements to boot. So maybe he knows what he's talking about?

Emphasis on maybe - I don't know because most of this stuff goes over my head. But if I constantly read about state of the art measurements with his gear, it has to count for something?


https://www.stereophile.com/content/chord-electronics-dave-da-processor-measurements

https://www.stereophile.com/content/chord-electronics-qutest-da-processor-measurements

https://www.audiosciencereview.com/...ew-and-measurements-of-chord-qutest-dac.5981/
His also trying to dishonestly sell his £8000 gear by claiming that noise/distortion thats well past audible for our ears is actually audible.
His "state of the art gear" would sound neutral/transparent to our ears just like nearly all of the dacs measured on this site costing 10x less.
The difference in measurements with the top of the line £8000 DAVE is also tiny like the difference between distortion in the 0.000x range, the £190 smsl su8 measures 0.0002% the £8000 dave 0.0001%.
 

Music1969

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#17
His also trying to dishonestly sell his £8000 gear by claiming that noise/distortion thats well past audible for our ears is actually audible.
His "state of the art gear" would sound neutral/transparent to our ears just like nearly all of the dacs measured on this site costing 10x less.
The difference in measurements with the top of the line £8000 DAVE is also tiny like the difference between distortion in the 0.000x range, the £190 smsl su8 measures 0.0002% the £8000 dave 0.0001%.
Yes, just above I wrote:

"I agree with this if we're talking Dave. But luckily Chord have something like Qutest in their lineup - not inexpensive but something more affordable and still with state of the art measurements."
 

solderdude

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#18
the £190 smsl su8 measures 0.0002% the £8000 dave 0.0001%.
What ? This means the Dave performs 2x better than the SMSL SU8 which equates to a 100% improvement over the SU8.
Surely a 100% improvement must be audible :eek: :p
 
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#19
Yes, just above I wrote:

"I agree with this if we're talking Dave. But luckily Chord have something like Qutest in their lineup - not inexpensive but something more affordable and still with state of the art measurements."
The Qutest still costs £1,100, its not really "state of the art", for a £900 less the smsl su8 gets very close to its measured performance the differences between them wouldn't even be close to audible and you could save £900 to spend on music maybe.
 

Frank Dernie

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#20
Just my personal POV but I believe Rob Watts designs good kit and his public utterances are because it seems that the vast majority of people prepared to pay serious dosh for Hi-Fi have fallen hook line and sinker for this sort of bollox and if they want to sell stuff profitably he has to pander to them.
The Chord stuff is beautifully made. I bought a used Chord Blu CD transport which is a joy to own and use. Yes I could probably have found something sounding the same but it is in my room and it isn’t a crap bent tin box with printed on logo.
On the basis that I have known for 40 years at least that the most expensive part of a Hi-Fi component is the enclosure (power transformer in amplifiers) I know a component as beautifully made as the Chord stuff will be pricey.
I accept that the Dave won’t sound better than the Qutest but to be “credible” to the people who are spending money on Hi-Fi they have to say it does, obviously.
Shame but the reality of the business, as Serge has said a business which is honest about how little one needs to spend on electronics to get top performance and the futility of upgrading electronics (usually) is not going to be in business long...
 

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