USB Cable discovery.

[slowGEEZR]

When it comes to digital cables, I have been skeptical of the various cable maker's claims of “improved” sound of their USB cables. After all, doesn't digital cable just transfer bits, not an analog waveform? So, many would say just buy a cable that meets the basic requirements of data transfer and be done with it. There's a certain comfort in that line of reasoning, a self-assuredness that comes from a basic understanding of data transfer between computers. A bit is a bit . Yet, I have heard multi-generations of copies of digital representations of sound and they clearly deviate from the original sound with each generational copy. I also know that all digital devices do not sound the same and it seems that “jitter” has been identified by many as something that has a deleterious effect on digital sound. Cable manufacturers of today are using testing equipment when creating their cables, not just their ears and passion, as in the early days of cable design. Some have said their cables reduce “jitter”, due to their construction. This was enough justification for me to try some different USB cables between my Mac Mini and my Ayre QB-9, in order to see if I could hear any differences in the resultant sound of music coming from my speakers.

My first USB cable was a standard $2 USB cable that met the requirements of data transfer. Using it, I thought the sound from the DAC was superior in every way to the sound I got from my Pioneer Elite CD/SACD player. In fact, the redbook music from the DAC was superior sounding to the SACD music from the Pioneer. I was a happy camper. Then, I read a very positive review of the Belkin Gold USB cable by Sam Tellig, of stereophile magazine. So, I spent less than $20 on one and replaced the standard cable I had been using. To my amazement, the sound seemed to improve. Specifically? Hard to say, but in general, it seemed to not be as edgy. All the frequencies seemed to be there, but the sound just seemed to be less harsh in some way. So, I had discovered that USB cables do make some difference in the resulting sound. Time to try some other cables.

First up was a $100 audioquest cable, loaned to me by a friend. I listened to this cable for a month or so, swapping the Belkin in from time to time, to ensure I was hearing what I thought I was. I preferred the sound overall of the Belkin. The audioquest had a slight smearing quality of high frequencies, that made itself apparent time and again. It also, somehow softened the sound slightly, which some may prefer, but I found to not be as lifelike to me.

Next was a one night usage of a $600 audioquest cable, loaned to me by the same friend. He much preferred this cable to the Belkin. Me? Not so much. To my ears, there was a certain sterility to the sound that made the music sound more like it was coming from a good Hi-Fi system, but not more like reality. I couldn't justify the amount of money for the sound “improvement”.

So, I was really satisfied with my Belkin and have been for two years, now. Then I received an AudioAdvisor sale magazine and saw an ad for a Pangea 24 gauge, solid silver conductor USB cable, in half-meter length for only $49. It seemed to have “the right stuff”, so I figured, for only $49, how could I lose? Well, I didn't. All I can say is, holy cow! This was money well spent. Bits may be bits, but I am now a true believer that the precise delivery of those bits is very important. What specific differences do I hear with the Pangea? An overall clarity, an increase in detail which allows me to hear more harmonics and complexity in sound. Take Amos Lee's voice for instance. Now, I can clearly hear a more complex voice, which contains a high frequency component/element I had not noticed before, which causes his voice to sound more real. Cymbals seem to have an extra depth of metallic sheen to them that is more realistic to what I hear when I go out to listen to live music. Little details, often hidden in the murk, appear to pop out a little more, which adds to musical realism.

I highly recommend trying out the Pangea before they go off sale. You can thank me later.

 

[amey01]

Well, generally a USB cable is not carrying clocked data - so jitter is irrelevant and can be taken out of the equation. I just notice you are using the Ayre QB9 - that is an asychronous DAC. Therefore the USB cable to the Ayre should have about as much effect on the sound quality as the USB (and CAT-6) cables between you and me will have on the accuracy of what I'm typing when you read it.

The same goes for mulit-generational digital copies - chain emails (for instance) don't deteriorate as they are copied around the globe from computer to computer. There is likewise no reason why digital sound should deteriorate in a strange way that doesn't apply to any other form of digitised data. It's very simple to prove - run a checksum over a multi-generational copy and it should be identical on the copy and the original if you take a reasonable level of precaution.

 

[Hi Fi Rōnin]

I spent about 2 years trying some different USB cables and I found the Locus Design Cynosure by far the most natural to my ears and continue to use it today.

 

[Rich]

I kind of fall in with Adam on this one, purely from a logical perspective. But I have never spent any time actually trying different USB cables, so according to the Bernard rule I don't really have an opinion.

 

[slowGEEZR]

Adam, Rich, I have been of the same opinion. How could it make a difference? My understanding of it is that as long as the bits are intact in the transfer from the source to the DAC, then the correct signal should be there. The way I'm looking at this is that if I hear a difference and I like it, then what is the harm? I'm out $49. I'm chalking this one up to, "I don't have enough knowledge to fully understand why, but...". Can jitter be introduced just by a connector? If I do a quick Google search on digital jitter, I quickly find many ways jitter can be introduced and many ways to try to filter it out.

Regarding copies of digital files. I have a CD of test signals and such and one track is a soundtrack of the sound of a bell and its subsequent copies down to 100th generation copy. Listening to this track, the first generation sounds clearly like a bell being struck, all the bell-like characteristics are there, such as the initial clang/stike with its corresponding ringing, until the sound fades away. Then you hear the 10th generational copy and it still sounds like a bell, but not as full and rich sounding. This continues, 20th generation, 30th generation, etc., until you get to the 100th generation copy. The sound is now a thud, not like a bell being struck in any way, but more like what you would expect to hear if you struck a thick piece of wood with a rubber mallet. I don't know how accurately these copies were made, but they were purely digital copies. On the other hand, I've read where someone made 99 generational copies of music and people couldn't hear any difference, so I assume there was some problem with the bell copies.

 

[slowGEEZR]

I spent about 2 years trying some different USB cables and I found the Locus Design Cynosure by far the most natural to my ears and continue to use it today.

I'm glad you found a cable that works for you. I fail to understand how these cables make a difference, but like you, I'm going to trust what I hear. In the great scheme of things, who cares if there really is a difference, as long as we hear it, that's all that matters!

 

[Hocky]

Regarding copies of digital files. I have a CD of test signals and such and one track is a soundtrack of the sound of a bell and its subsequent copies down to 100th generation copy. Listening to this track, the first generation sounds clearly like a bell being struck, all the bell-like characteristics are there, such as the initial clang/stike with its corresponding ringing, until the sound fades away. Then you hear the 10th generational copy and it still sounds like a bell, but not as full and rich sounding. This continues, 20th generation, 30th generation, etc., until you get to the 100th generation copy. The sound is now a thud, not like a bell being struck in any way, but more like what you would expect to hear if you struck a thick piece of wood with a rubber mallet. I don't know how accurately these copies were made, but they were purely digital copies. On the other hand, I've read where someone made 99 generational copies of music and people couldn't hear any difference, so I assume there was some problem with the bell copies.

The only way that this could happen is if someone is burning a copy to a CD with a crappy burner on a crappy CD, then copying it back off with a dying CD player. Digital copies are easily created perfectly.

 

[amey01]

On the other hand, I've read where someone made 99 generational copies of music and people couldn't hear any difference, so I assume there was some problem with the bell copies.

It's not so much whether you can or can not hear a difference. It is very easy to prove outright whether the copy is or is not identical with a quick checksum.

Can jitter be introduced just by a connector?

Yes. It can easily be introduced by a connector. But for jitter to even be worth mentioning, there has to be a clocked signal on the bus first. (eg. with S/PDIF). Jitter is not some magic "catch-all-we-can't-explain" with digital connections. If the signal is not timed, how can we even mention timing errors?

Asynchronous USB is not timed - that's the whole point of it. It transfers data just like a computer would transfer a bit of text to a hard disk.

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When I acquire a 24/96 file from the internet, it has been through untold number of USB/CAT6/interfaces/encryption/decryption/twisted pair/optical cable/encoding/firewalls/etc. But when it reaches my computer it is perfect. A checksum confirms that. I don't think anyone will argue with me there?

All quiet? Good. So continuing......

An asynchronous USB cable is only one more step in the process - whether this particular cable happens to be in your listening room or at your ISP's data centre. Or even 2 kilometres under the Pacific Ocean. Or in a satellite out in orbit. It is just transferring data. The DAC buffers it and then commences processing - yes, from that point: everything matters.

In the great scheme of things, who cares if there really is a difference, as long as we hear it, that's all that matters!

I get your point but I don't agree. Why put time/effort/money into imaginary differences when you can spend that effort and money investing in real improvements?

 

[asindc]

Well, I've tried several different USB cables in my system, and I have heard differences between them just as much as I have with different analog ICs or power cords. I can't speak to what others might be imagining, I am only speaking to what I've heard.

 

[Bernard]

I kind of fall in with Adam on this one, purely from a logical perspective. But I have never spent any time actually trying different USB cables, so according to the Bernard rule I don't really have an opinion.

Peace Rich

 

[Rich]

Peace Rich

Just ribbing you, Bernard.

 

[slowGEEZR]

I get your point but I don't agree. Why put time/effort/money into imaginary differences when you can spend that effort and money investing in real improvements?

All your points are well taken. Thanks for the effort. As far as the last point, $49 is really not very much and it the improvement it made to my system was worth it. This cable is shorter and looks much nicer.

 

[amey01]

All your points are well taken. Thanks for the effort. As far as the last point, $49 is really not very much and it the improvement it made to my system was worth it. This cable is shorter and looks much nicer.

And $49 - you can't argue with that. Maybe even I'll get one??