The Absolute Sound "review" of USB cable reads suspiciously like a press releaste

Don't you people buy these, as such you should expect your advertising dollar (purchases) being spent in this way!  Why the objections?

Again, the fact that the input sequence is not perfectly timed is not relevant providing the data recovery circuitry/algorithms are able to cope with the imperfections. The use of data corrections (CRCs etc) can ensure bit perfect output sequence results. The use of quality retiming can ensure extremely low jitter prior to the conversion (or indeed during the conversion) to analog.

For high rate data recovery PLLs with jitter in the 100fs region or lower are de rigeur. For audio the best PLLs/DLLs used are sub ps. The theory concerning the eventual SINAD of the data at the output and the resulting impairments is quite clear. There's a reason that digital recording/playback of audio has improved by so much in the last three decades.

One other thing that needs clarification- the concepts of bit perfect and low jitter are NOT homomorphic.
Bit perfect simply means that the recovered output data sequence is the same as the original input sequence- which in turn means that the recovered output changes in state are within the correct timing windows.
It tells you nothing about the stochastic and deterministic components of the jitter other than the combination of both in any given timing window does not cause the data to fall outside the recovery region.

“There’s plenty of room for the introduction of timing errors/jitter in that process even if the result is ultimately bit perfect.

“Ideally the DAC will retime the input data to restore a pristine, low jitter, bit perfect, data sequence for conversion to analog.”

>>>In my view the damage is done immediately and irrevocably as soon as the laser reads the data. The primary reasons why the CD playback process is imperfect is due to scattered laser light getting into the detector and vibration of the CD player and CD itself. The nanoscale geometry involved - laser beam width, pit depth distance from laser to the CD metal layer - makes the job of the servo mechanism, especially with all the vibration that is occurring, impossible. You get what you get.

The USB cable argument is probably more similar to the digital cable argument. Or so it would appear.

Incidentally, the same kinds of circuits/techniques are used to recover data for high speed data links such as is used on the backbone of the internet. The jitter requirements for those applications are orders of magnitude lower than the needs of audio and although the noise bandwidths are different the issues remain the same, particularly as modulation of the phase and/or modulation of the amplitude is used to increase the data capacity.

Perhaps you view it that way. I do not. CD readback is imperfect because there are mechanical and optical imperfections in the recording and playback processes that result in timing issues and there also is stochastic jitter. These processes are intrinsically more complex than the rather simple USB interface impairments.
The attached CD data recovery circuitry is tasked with the restoration of the near ideal bit sequence that then is applied to the DAC. 
There's plenty of room for the introduction of timing errors/jitter in that process even if the result is ultimately bit perfect.
Ideally the DAC will retime the input data to restore a pristine, low jitter, bit perfect,  data sequence for conversion to analog.

Actually it’s the same argument. The CD argument is that digital data encoded on the CD cannot be changed and that laser servo mechanism + error correction together ensure that the 1s and 0s maintain their integrity all the way to the DAC. It’s called the 1s and 0s argument. It’s the same argument used to “prove” that there’s no difference among digital cables, that 1s and 0s are being transmitted by the cable so aren’t affected by rf or vibration like analog signals are.

The arguments are dissimilar.
This is not about whether a digital format produces a perfect reproduction of an analog source or otherwise.
This is about whether the USB data transfer protocol is bit perfect as long as the interface is spec compliant- including the transmitter and receiver.
The answer to the latter question is yes, it is.
The answer to the former question is far more complex.
There is some possibility that the USB can introduce noise through the ground connection. The USB receiver can be designed to eliminate the possibility of ground loops. However, sometimes the problem does occur.

By the way, to put this in context, my system is tri-amped with a sub woofer and a pair of slightly modified ML Montis, The electrostatic panels are driven by one of the following- Rogue M180s, Hypex Ncore 400s or a Benchmark AHB2, depending on my whim. The non electrostatic units are all driven by DSP equalised class D amps.
The preamp is a modified Hovland HP100 or a home made phono amp driving a digital ADC/DAC- the RME ADI-2 PRO FS. My cables are all home made (except for the USB ;-))
My cartridge is a Miyajima Madake. I also have many 15IPS 1/4" 2 track tapes- safety masters or similar- that I play on a Otari MX50.
I have digitized many LPs/tapes and I play them back with the RME device using a USB connection.

Hey, look here, another 1s and 0s argument! 🤗 We got our own 1s and 0s argument going over on the CD thread right now. “Theoretical question about how CDs work.” Experts urgently needed to straighten us out! The 1s and 0s argument is used to prove that CD really do produce perfect sound forever. We had a similar thread regarding digital cables recently. Yup, same 1s and 0s argument.

@wynpalmer4

Bravo!

I come from the IT engineering profession as well. I have that Amazon USB cable on my high-end system and it sounds stellar. I’ve tried several different cables, just to prove the theory, and there is no difference. If the DAC is good quality it is what makes the sound with it’s clock. The computer/server doesn’t know the difference. This is science we have known in IT since USB came of age.
Thanks for the straight talk from an expert!

Rollin.

I'm a Design Fellow Emeritus for Analog Devices and for a number of years I designed retiming PLL and DLL loops for various interfaces etc. including USB. The 1s and zeros that you refer to are generally caused by current changes into a fixed load at the receiver that matches the characteristic impedance of the "transmission line" that is the USB cable in order to minimize reflections.The data is also sent in packets retimed at the receiver. This retiming occurs "perfectly" as long as the transitions from 1 to 0 and back occur in a given period of time- a so called retiming window- the purpose of which is to eliminate the effect of the finite bandwidth and jitter of the interconnect/transmitting system. The receiver adds its own imperfections to the reconstructed data stream, but as long as the cable, transmitter and receiver comply to the standards the resulting data stream will have a one to one correspondence to the source. In addition, the data is checked upon reception using a CRC and if the packet is corrupted it will be dropped and the host can be asked to resend it. So, obviously, the system is not a dumb one and in reality- spec compliant cables CANNOT matter in an analog sense. 
USB2.0 is also able to transmit 480Mb/s so audio bit streams are well below the max. 
I've heard audio streams where the USB data is actually corrupted and packets are being lost.
The result is not subtle...

Are there two bdp24's? I don't even know what UBS means. You musta got me mixed up with one of the other good lookin' guys.

Again, the OP link to the TAS article is a not a review.  It is clearly an advertisement for the USB cable.  

The rags are not the hobbyist, today they are sales for audio companies, they are partners. Anyone can see that by reading and how they create trends for companies and many at times are short lived and folks are stuck with a product with little to know value. At best they only write opinion and get to have free\long term loans and the best perk if they wish buying at a industry accommodation, but why they would when they get contact gear to review is beyond me. Mags are there for them, how else can they charge so little for their year renewal. Fun to read, fun to see the ads, but this hobby is 0.5% of the consumer who buy, thus as we age and the market slowly dies you see the marketing and cost focus on the well off with lots of disposable income, where the middle class spend money on their kids, education and putting food on the table. $1,000 power cords, $5,000 amps even buys them a lot of food, education and family needs. THe mags don't write for them and manufacturers don't either.   

Hey andy2,

Well, I summarized what another reviewer mentioned, so I'll post the link here:https://6moons.com/audioreview_articles/audiocadabra/

The beginning of the review has a primer for the hows and whys of USB cables. In it, he states that the audio signal has to arrive in an uncorrupted form as it cannot be reassembled on the receiving end, it being not just ones and zeros, but a signal current representing ones and zeros. Once the representation of the signal is damaged (by jitter), it's over. Or something like that. 

He's been around a long time and knows a thing or two about asynchronous USB architecture as well.

All the best,
Nonoise

Nonoise,

Today, most, if not ALL, USB DAC use asynchronous USB architecture which uses a local clock to clock in the data, so data jitter is no longer an issue.  Therefore you have to be able to explain at least in theory why data jitter would affect the clock.  In other words, the data is buffered in a memory bank so jitter coming in from the USB cable is neutralized.  

I am playing the devil advocate to force you to explain.  

It's not just ones and zeros. Like stated, it's a representation of ones and zeros (+200mv for one, -200mv for zero) and it must be stable and unaffected. Per USB regs, USB 2.0 cable must have an aluminum shield covering 100% of the cable and a copper shield covering at least 65% of the cable, and it must handle a 90ohm impedance while conveying 480mB of data density per second. Also, the data wires must be at least 28GA copper and the power wires 20-28GA.

How many, crummy, off the shelf or amazon bought USB cables does anyone think meet those requirements? Or just barely using crappy quality materials?

All the best,
Nonoise

The OP link to the TAS article was not meant to be a "review". I don’t think TAS made any claim that they actually reviewed the cable so the OP opinion was not accurate.

Here is a better review of various USB cables. It was an old review so some of the USB DAC hardware architecture used was somewhat obsolete and today it is much better but it was informative. Today we use asynchronous USB DAC architecture so it may not be as sensitive to USB cables as in the past as was done around the time of this article.
http://mvicha.sweb.cz/test%20USB%20kabelu.pdf

First in order to convince that USB cables do make a difference, people in the business have to be able to articulate at least in theory why would a USB cable would make a difference.  Using common sense, if you can't prove that something on paper make a difference, then how can you convince that it would make a difference in real life or in practice.

Here is a question posed to some of the more prominent cable designers in the industry and, at least IMO, after reading through all their responses, they can't seem to articulate why such USB cable would make a difference in theory.  This comes from a HiFi+ article awhile ago.

How do you answer those who argue that specialised digital cables don’t and can’t make a difference since digital audio is ‘all ones and zeros’ anyway?

“(Laughs) No argument there—you would
not be talking to an audiophile. The fact is
that digital audio is ‘all ones zeros’ and time.
In digital cables, clocking and time arrival
integrity is crucial to musicality. When the
timing aspects of digital cables are right,
the sonic differences should be (and are)
obvious, so if you can’t hear a difference, don’t buy the cable.” George Cardas of Cardas Audio

“First, there is no music until something
vibrates, electrically or acoustically. Second,
in terms of cables, a digital cable “pulses” off
and on quickly. If the cable does not vibrate
in sync with the music signal, there will be errors. “ Bruce Brisson of MIT


“I don’t argue this point. All cables affect
the final sound of a system so if they don’t
understand this, it’s obvious they have not
listened or can’t overcome their negative
expectation bias. Amusingly there is no
such thing as a “one” or a “zero” where
digital transfer through a cable is concerned.
There is only an analogue signal, which
is “interpreted” as a one or a zero, so
there really is no difference between why
analogue cables effect sound vs digital
cables effecting sound. All cables affect sound in a system.” Ted Denney
of Synergistic Research

“Sit down and shut up and have a listen! Any digital cable
(with the exception of optical cables) in a
hi-fi system is carrying an electrical signal.
That signal is as subject to interference and
mechanical noise as any analogue cable is.
We’ve already mentioned how critical we
think the relationship between conductor
and dielectric material is and if anything, this
is more so when it comes to digital cables.
For the same reason, the quality of shielding
and the ability of that shielding to work
at high frequencies are also critical. One
of the areas of musical performance that
digital cables seem to have a profound effect
on is the coherence with which music is
presented. Producing cables that are able to
carry a musical signal coherently is, we think,
fundamental to every cable design.” Nigel Finn of
The Chord Company
“It might start out as “all ones and zeros”, but
the signal from the output must change from
one to the other and the input device has
to determine at which point a one becomes
a zero and vice-versa. If a cable causes
the voltage rise time to lag or linger it will cause problems.” Ray Kimber of Kimber Kable


“Digital signal is ones and zeros, a lot of them!
However, those who argue against the use
of specialized digital cables overlook one
exceedingly important factor which is the
“timely conveyance” of all of those ones
and zeros. In some digital components the
lack of timely conveyance of digital signal
is referred to as jitter. The electric current
in all cables, by which digital information
is conveyed, is impacted by conductivity,
dielectric absorption, impedance, eddy
current resistance and correspondingly
the integrity of the timely conveyance of
the massive amount of digital information
is also altered. At the end of the day, I use
the most sophisticated and precise test
instrumentation in the world, the human
hearing system. And, by that standard alone
it is clear that different digital cables have a big impact on the sound.” John McDonald of Audience


“The digital signals that are used in our audio
equipment are not dissimilar to an analogue
signal, only that they are constant amplitude
but still constitute numerous frequencies.
Exact representation of these frequencies in
relation to triggering and lack of unwanted
interferences influences the end result—the
music that we hear. It is really the DAC that
interprets the signal as ‘zeros & ones’. The
signal itself is just made up of waves, albeit
square waves.” Touraj Moghaddam
of Vertere Acoustics


“We are confident that we can demonstrate
the positive differences that come through
using our digital cables in music systems,
making for a far more enjoyable listening experience.” Graham Nalty of Black Rhodium

“We the only specialized manufacturer
of HMDI and 4K UHD cables in North
America, Nordost has put a lot of R&D into
digital transmission. We have found that
when digital cables are being used, it isn’t
numerical 1s and 0s, but analog square
waves that represent 1s and 0s that are
actually being transferred. The “less square”
a wave is, the harder it is for a DAC to make
a distinction between the so-called 1s and
0s, which results in timing errors. In order to
achieve sharp analog square waves, the cable
must have a large bandwidth and be capable
of high transmission speeds. Therefore,
quality cable design makes a tremendous
audible impact in digital cables.” Joe Reynolds of Nordost

“I explain that those ones and zeros pass
through cables as streamed waveforms with
jitter that creates measurable data errors
that change the sound we hear. I also offer
to send them white papers published by test
instrument manufacturers on that very issue.” David Salz of Wireworld

“They’re correct in that the ones and zeros in
the data remain ones and zeros through the
connecting cable. Where it all goes to hell is
when it’s converted to analog at the other
end, and that is where the connecting cable
and equipment interactions wreak havoc
with the clarity of the sound.
A digital source outputs data, and noise.
The quality of the cable determines both
the integrity of the data and how noise
travels. Today’s digital gear should be looked
upon as an RF system and while designed
to play through faults, the quality of the
analog output, particularly the very low-level
signal portions that brings about a sense of
space and other life-like qualities, is highly
dependent on the care taken in the transport
of the digital signal. Resolution is not black
and white, but rather shades of grey.” Joe Skubinski of JPS Labs

“The zeros and ones are not the problem. It
is about jitter and noise causing a different
sound. Jitter causes timing errors, easily
heard as an unpleasant sonic effect.” Edwin and Gabi Rijnveld
of Siltech and Crystal Cable

@elliottbnewcombjr

" Who among you believes the construction of a USB cable will make an audible difference?"

You know, I would like to believe that it couldn't.  But I just recently tried a different USB cable between my server to my DAC and it made an unmistakable difference, and all to the better.  Like buying better DAC can.  I don't like it, either, but there is no denying it, IME.  It seems we need to fiddle with this cable, too, to tune our systems in. Oy.

@jond ,
Agreed. I've seen this type of thing many times before with other releases of new product. Sometimes, when perusing reviews at dailyaudiophile.com, I'll notice a few sites that have the very same mention of the very same product.

Some don't even bother to change a word while others edit it slightly, to give their readers the impression that they were the ones to discover it.

It looks like what TAS did put their spin on a simple press release. What I don't understand is some here getting a good case of the vapors.

All the best,
Nonoise

I've read TAS for years and I get their email newsletter. The newest one just came today. The headline reads " Reviews: KEF, Triangle, Nordost, Muraudio | Joe Lovano". The Nordost refers to the USB cable.

It doesn't look like this is a mistake and it's pretty disturbing. I read both Stereophile and TAS and generally I trust their reviews. They are a tremendous help in buying used equipment that I cannot audition. This "review" blatantly crosses the line between an actual equipment report and a paid advertisement. Shame on TAS.

@nonoise it clearly reads as a press release, TAS has a separate News tab full of press releases and this is filed under Equipment Reports. More likely a simple mistake rather than something more nefarious or lazy.

Absolute announcement/press release, idiotic of them to show 'equipment report' and have someone's name attached to a press release.

However, ignoring AS, let's talk Pied Piper Effect.

Who among you believes the construction of a USB cable will make an audible difference?

As others have suggested it IS a press release, not a review. But the OP’s concern is legitimate, because TAS chooses to deceive by calling it an "Equipment report", and by putting someone’s name in a byline.

It IS dishonest, but no doubt helps TAS to generate advertising revenue from the companies that benefit from the deception.

I agree, but do enjoy glistening and disappearing hi-hats although I wonder, where do they go?

What I don't understand is how anyone can confuse this with a review.

“Until you get to hear any product it’s best to treat all reviews as mere infomercials”

Well said, @cd318.  Same goes for full page advertisements in TAS and Stereophile. 

Hi, this is Consumer Man. I just had to chime in and say how nice it is to see someone is on the job and protecting the consumer within this forum... And i mean that sincerely, i take my consumerism seriously and a reviewer masquerading as a "reviewer with an agenda" appears to be typical of todays standards. Keeps us on our toes if nothing else..  

It says Equipment Report in the top right corner. A press release masquerading as a review pretty sad.

For sure 1010 binary  ,digital cables do matter and some are much better then others, digital errors = jitter or digital noise. That being said these paper and online magazines have a ton of politics , one hand washes the other .
having owned a Audio store until 08 and speaking with many companies at the shows in the past. Sadly several exceptional products went belly up because the big magazines wanted $50k + to guarantee excellent exposure and reviews.
many small companies could not afford this, This rest is history.

It surely reads like an advertisement.

As one of the responders under the original "article" noted the description...."purpose built". It must be the highlight of the "equipment review".

On the other hand, maybe there is not much to say about an USB cable after all. I am not trying to start a cable thread and have no opinion about it, just wondering.

It’s by Michael Mercer! I wondered what happened to him.  Interesting fellow.  

Stereophile is the same just better at hiding it. Corruption is unavoidable if your publication depends on ad revenue. For the record, corruption doesnt have to be anything as insidious as pay to play it can be much more subtle like not giving a superior product its proper due if such an acknowledgement would alienate a long time favorite. 

I gave up on TAS years ago.

Until you get to hear any product it’s best to treat all reviews as mere infomercials.

The number of times I was left feeling underwhelmed upon hearing an hitherto highly recommended product...

Basically, after buying a basic amp, CD player and some decent speakers you’re all set to go.

Reading all the subsequent high falutin reviews can lead you to believing there are sonic paradises undiscovered just waiting your attention.

It clearly ain’t so.

Not this side of the Living Voice Vox Olympian / Kondo amps combination at any rate...

It's not a review. It's a press release. All mags and 'zines do it.

erik_squires Been reading TAS for some years. This one just seemed particularly egregious.

Exactly Erik. ALL their "reviews" sound like press releases, and have for many years. I met and spoke with Robert Harley when he was at Stereophile, and he seemed legit. But he, like William Barr, appears to have been drawn to the dark side and ethically compromised ;-) .

New to TAS??