The Great USB cable debate poll

Still a digital signal way less veriance in what needs to be received from the actual electrical signal being passed through the cable.

 

Something similar crossed my mind yesterday -- wouldn't a cheap DAC be more vulnerable to whatever problems might be created by using cheap USB cables?

 

I hope that slap knocked some sense into your logic. Plasters are available at reception. If you want to bring duff logic into it, be my guest. The loss is yours.

 

This is exactly where I am at as well.

 

Nothing but perfection, as seen here: https://www.google.com/search?q=usb...a=X&ei=Gk3yVLK1JcnzoASQloKIBQ&ved=0CAcQ_AUoAg

 

Given the availability of this kind of test and visualization, you might expect to see audiophile cable manufacturers employ it to demonstrate why their product is better than the "leading brand." But add the word "audiophile" to your search, and you'll see that there aren't very many results. Admittedly I didn't look for long, but this was the only one I saw: http://www.neo-w.com/english/d_usb-2.html Even allowing for the clumsy translation, it's ridiculous. There is an eye diagram, and an untrained eye like mine can see what looks like a difference in the results; the manufacturer's cable produces a more pleasing shape than the generic. But what inference should we draw from that? The diagram is given without any explanation or interpretation other than a cursory description of its type.

I find this representative of a lot of marketing copy for this sort of product. There are references to concepts from science, engineering, and technology, and good manufacturing, but there's no report from any experimental application of those concepts, no data at all on the significance of any choice made in design, offered to support the claims made for the product or its price. Why not? The information can't be all that hard to gather.

 

Yeah, I agree, it's weird. Maybe some audiophile company will try it in our lifetime. I imagine it would help, but it seems they have imagined otherwise so far.

 

Good post...

An article about eye diagrams:

"The transmitter, PCB traces, connectors, and cables will introduce interference that will degrade a signal both in its amplitude and timing." (emphasis mine)

http://www.edn.com/design/test-and-...gram-Basics-Reading-and-applying-eye-diagrams

 

The thing is you don't need a "perfect signal" it just has to be good enough to convey the voltage gains and drops that convey to the DAC the values of 1 or 0 and any cable that's in good shape and meets the standard will do it well enough and fast enough. If the manufactures of these cables could prove beyond a reasonable doubt their 200 dollar cables could make a difference don't you think they would've.

You could add or subtract interference to make the scope picture look anyway you want.

 

Copied from the article two posts up.

"The effect of termination is clearly visible in the eye diagrams generated. With improper termination, the eye looks constrained or stressed (Figure 3a), and with improved termination schemes, the eye becomes more relaxed (Figure 3b). A poorly terminated signal line suffers from multiple reflections. The reflected waves are of significant amplitude, which may severely constrict the eye. Typically, this is the worst-case operating condition for the receiver, and if the receiver can operate error-free in the presence of such interference, then it meets specifications."

No where in that article does it talk about 200 or 2000 dollar cables. It talks about meeting the standards and specs.

 

Sometimes Occam´s razor is right there in front you and you don´t see it. It is of course most reasonable that normal USB-cables works according to spec, while many other more obscure ones don´t in the same way. This would explain why some are reporting differences even in somewhat controlled tests, but at the same time cannot confirm any better sound. It also explains why any real data of a better functioning cable always are absent.
This would coinside with my own experience, and also with some uploaded file on differences.

 

OK .. so for a minute lets just say that cheap cables, for whatever reason, don't allow a perfect data transmission from the source to the DAC ... I am still waiting to hear an explanation as to how this lack of data (dropped packets, squashed square waves .. whatever) can manifest itself as audio differences like improved imaging, deeper soundstage, or whatever other magic happens.

In any other form of digital transmission, it either works or it doesn't. Satellite TV is a perfect example. A digital datastream is sent via an analog signal from the satellite. When it rains, the analog signal degrades to the point that the DAC no longer has enough information to decode the audio/video. But until the signal drops to that point, the sound and picture are perfect. The video does not get fuzzy or turn to black and white, the audio does get muddy or fade between stereo and mono. It all just goes away.

Also keep in mind that satellite TV is a one way communication. There is no retransmission of dropped packets .. just a one way stream.

So why is digital audio different via USB?

 

No, because often the sound is embedded into video files being prepared for theatrical release, and if the cables affected the sound, they'd affect the picture and vice-versa. The i/o people do a checksum verification to make sure that the copied files are 100% bit-for-bit identical to the original. We often routinely receive files nowadays on very average USB3 drives that are pulled into the film for an edit -- no special cables, no nothing. In truth, the cables are extremely short (typically 3' or less), and there isn't much you can do to a 3' cable to make it better or worse. It works or it doesn't.

 

So you are talking about a file transfer over USB then.

 

Yes. I think carrying a file from a hard drive to a D/A converter is no different and the bits won't change. The errors can be measured fairly easily.

The D/A may convert the file to analogue and change the sound in some way, but I think this is generally more subtle than people think. But I have heard differences between different D/A converters, and I could also measure them (particularly when one is noisier than the other).

 

Because they have a closed mind. They are binary thinkers. Black or white. On or off, etc. Just like fu#king digital!

That is the mind of the typical electrical engineer and wannabe "scientist". They think they have it "all figured out" and that's all there is.

There is no real mystery, wonder or magic in their life.

That is why I'm an artist.

Embrace the mystic! For it is profound...

 

The above post was brought to you courtesy of the Comedy Store.

 

Making lots of great points, guys...........well done, I didn't expect them to be as good as that.

Meanwhile I'll do what works in my system, and I hope you guys do what works for you

 

I'm fine thanks TD. Glad the humour bypass was such a success.

On the other points you raise, music is indeed a great artistic endeavour. Data cables aren't. $3000 data cables somewhat less so.

Artistic endeavour, genuine engineering, yes, great things to aspire to.

Mystical musings about data cables? I'm with Vidiot on this one.

And I would point you towards my earlier posts on this thread directing readers to the NWAVGuy blog. His design for a DAC has been taken up by several firms (ref: ODAC - Google it).

Now, of course, I completely get the notion that any fool can knock up a blog. His however is well researched, and he appears to be qualified. Have a look and see for yourself.

The issues that proponents of audiophile USB cable haven't yet confirmed on this thread are that, issues of protecting data transfer aside, the audible impacts in their view haven't been defined. I might be wrong or may have missed it but don't recall seeing that.

I think it's very relevant you picked Apple. I completely agree. Of course, Apple also gave us gapless ten years ago and I note with interest that appears to be an issue for some of or other audiophile visionaries out there still today. Nice shout!

It's also interesting that on another thread that you said you had no use for Apple's "consumer crap". I don't think you can hail Apple for the iPhone and iPod as visionary here but it's crap on another thread. Makes your position on at least one of these threads rather suspect I think.

 

LOL

No matter how well researched, or qualified.........many get it wrong. You only need to look at all the qualified folk on the net that are at odds with each other, on a range of audio related subjects

 

Oops.

 

There is no art in paying 100x what you should for a USB cable. Purchasing audio equipment is not an art.

Now the people who sell the cables might be (con)artists but I guess that is still TBD according to this thread.

 

Either that of go with conspiracy theory's, where everybody selling something is out to rip you off.

For clarity, I see value in looking for a good cable up to two or three hundred max, there are good buys and bad buys in each segment. But then you wouldn't look at that price bracket if the components at either end are of a similar value.

I don't even touch on the hugely expensive cables, as I see no need to........but some folk like to, for point scoring reasons

 

I think it's totally valid to spend what you want. I also use cables sound the same price point - £200-250.

I just happen to think it's fair to call out some of this stuff and especially the kind of USB cable that Vidiot linked to earlier. This comes down to buying this stuff from an informed position.

The audible impact hasn't yet been established bend claims and yes, you might call it point scoring, but when someone lauds Apple for ingenuity on one thread and in another refers to the self same products as "consumer crap", then it's fair to highlight that too. Not least when they're questioning the validity of another poster's contribution to a thread!