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USB cable and Sound Quality - Page 7  

post #91 of 783

Hi Guys... just my experiences and $0.02. I've been doing electronics since I was 10, have an EE degree, have been making a living in electronics for 30 years and have been an Audiophile for about 35 years. The brain suggests that bits are bits and the USB cable shouldn't matter. Real world experiences  and my ears tell me just the opposite, and it's not subtle, at least with my system and my ears. It's difficult to explain the reason as to why this is so from an electronics/physics standpoint. My guess is that it's mainly an issue with timing/jitter and perhaps isolation of the power lines from the data lines. The jitter issue is a difficult-to-explain and complex relationship of micro-vibration, dilectrics, conductor type and geometry. To this day, my brain says this doesn't really make any logical sense. My ears tell me the exact opposite. In the end, my ears won the debate hands down.Going back to a standard USB cable robs my system of the that magic make makes you forget that you're listening to just another good stereo. It all started with a Locus Design Polestar and then I upgraded to a Locus Design Axis, using Audirvana Plus, a Mac Mini and a Wyrd4Sound DAC2. I miss Lee Weiland... he was a cable genius,  a gentleman and an awesome guy. Whatever the secrets of USB cables really are, I think he knew most them. All of this being said, if you can't hear the difference, that's OK. Then USB cables are a non-issue for you. It really boils down to what you do or don't hear. If you try a good USB cable and you can't hear the difference, then that's that. On the other hand, if you do hear it, then it becomes of case of, "Is it worth it or not". Pretty simple really. If you haven't tried it in a nicely controlled experiment, then your opinion is nothing more, nothing less than a best guess. It doesn't take DBT. If it's that subtle, then it's not worth it to me. I've demonstrated the difference to four friends. They all heard the difference, and had a bewildered look, in about 30 seconds of listening. In my system at least, the difference is anything but subtle. You millage may vary and probably will. Again, this is just my $0.02... the last thing I'm looking for is a fight. I'm just trying to share my experience with you guys in the hopes that the music you love can become (even more) alive. Happy listening and happy experimenting everyone! High-end audio is awesome!

post #92 of 783
I hope i hear a difference:)
But you have probably opened a can of worms, lol.
post #93 of 783
I think jitter and timing is a convenient theory to explain every non-verifiable subjective impression. I'm beginning to read it as a synonym for "imagined".
post #94 of 783

So hifuguy, you and your friends could not only pick out the different cables blind, but could also come to a consensus of which sounded better (without knowing in advance which was which)?

post #95 of 783
Quote:
Originally Posted by hifuguy View Post

Hi Guys... just my experiences and $0.02. I've been doing electronics since I was 10, have an EE degree, have been making a living in electronics for 30 years and have been an Audiophile for about 35 years. The brain suggests that bits are bits and the USB cable shouldn't matter. Real world experiences  and my ears tell me just the opposite, and it's not subtle, at least with my system and my ears. It's difficult to explain the reason as to why this is so from an electronics/physics standpoint. My guess is that it's mainly an issue with timing/jitter and perhaps isolation of the power lines from the data lines. The jitter issue is a difficult-to-explain and complex relationship of micro-vibration, dilectrics, conductor type and geometry. To this day, my brain says this doesn't really make any logical sense. My ears tell me the exact opposite. In the end, my ears won the debate hands down.Going back to a standard USB cable robs my system of the that magic make makes you forget that you're listening to just another good stereo. It all started with a Locus Design Polestar and then I upgraded to a Locus Design Axis, using Audirvana Plus, a Mac Mini and a Wyrd4Sound DAC2. I miss Lee Weiland... he was a cable genius,  a gentleman and an awesome guy. Whatever the secrets of USB cables really are, I think he knew most them. All of this being said, if you can't hear the difference, that's OK. Then USB cables are a non-issue for you. It really boils down to what you do or don't hear. If you try a good USB cable and you can't hear the difference, then that's that. On the other hand, if you do hear it, then it becomes of case of, "Is it worth it or not". Pretty simple really. If you haven't tried it in a nicely controlled experiment, then your opinion is nothing more, nothing less than a best guess. It doesn't take DBT. If it's that subtle, then it's not worth it to me. I've demonstrated the difference to four friends. They all heard the difference, and had a bewildered look, in about 30 seconds of listening. In my system at least, the difference is anything but subtle. You millage may vary and probably will. Again, this is just my $0.02... the last thing I'm looking for is a fight. I'm just trying to share my experience with you guys in the hopes that the music you love can become (even more) alive. Happy listening and happy experimenting everyone! High-end audio is awesome!

 

There have been a few credible studies of jitter audibility involving DBT and controlled levels of jitter both random and deterministic. To date the level of jitter that creates verifiably audible distortion is approximately 2 levels of magnitude higher than that found in generally competent digital components - viz there is no rigorous study that indicates that jitter is normally an issue.  

 

As for your cable experiments, these are uncontrolled sighted listening tests prone to all sorts of human biases and of zero value in this subforum, this is the one subforum where we are allowed to request a higher level of evidence and anecdotes ("now just listen to this cable") such as you recount are simply insufficient for that purpose.


Edited by nick_charles - 8/14/12 at 12:15pm
post #96 of 783

I have a few questions on jitter on USB cable that people attributed to in audio.

 

1. If jitter is caused by the cable, this means the DAC's local clock must be synchronous to the transmit clock. USB 1.0 is 1.5Mbit/s and 2.0 is 480Mbit/s. The audio clock is 44KHz. How does this translate?

2. If the local clock is indeed synchronous to the USB clock, what about the tolerance of the clock? Won't that change the audio playing at all? In this I mean if the recording is done at 43KHz sampling and the derived clock from the USB clock is at 45KHz, won't that be more detrimental.

3. What if I am streaming audio, what is the local clock synchronous to?

4. How does jitter change the value of a stream so you'll better highs and lows? Do I have to worry about my banking transaction if that indeed is the case.

5. What does jitter sounds like?

post #97 of 783
Number 5 assumes that jitter is audible. In the real world, it isn't.
post #98 of 783
Quote:
Originally Posted by bigshot View Post

Number 5 assumes that jitter is audible. In the real world, it isn't.

Yes, but people that claim jitter is the cause of quality degradation never describe the sound. There is a theoretical sound and it ain't grainy high and smaller soundstage.

post #99 of 783
I had one stereo salesman describe it to me as a buzzing vibration in the sound. As if someone could possibly detect picoseconds as discrete bumps in a vibration pattern!
post #100 of 783
It sounds like there are a bunch of ants crawling around in your Stax.
post #101 of 783

Hi Guys.... there really is no question in my mind, the high-end Locus Design (yeah, expensive) USB cables just sounds way better in many of the usual audiophile terms (that get kind of tedious sometimes), but the bottom-line is that it makes me forget it's just a very good stereo. With the fancy-pants USB cable It is able to transcend that and make you feel like you are at the musical event (at least on better recordings). Going back to a regular USB cable makes you feel like you're missing the magic. I really wish I could say why with authority, but other than the items discussed previously, I can't explain it in a proof that cable skeptics can/will accept. On one hand, If you have tried this experiement on a good system, but you can't hear it, then anything anyone says about it doesn't matter... it's simply not your reality and that's just fine. One the other hand, at least with the system that I have, I can assure you that I could pick it out every time.... I'll bet many (most?) you could too. I only bother to write all of the this because the addition of the USB cable really raised my level of musical enjoyment, and I wanted to share it with others. Also I should note, that I have a data sample of two! The Locus Design Polestar and Axis. I can only vouch for these two, as they are the only ones that I have personally heard. I can appreciate the very nature of this forum seeking to merge signal propagation theory with the art of real-world audio cable production... it would be swell if they match-up. If they did, then the suggestion would be that we know every nuance of how it works. But the logic of suggesting that if you can't measure it, can't explain it then it can't be possibly be true or of musical value to our hobby and our love of music escapes me. I think I'm going to go away now. Thanks for reading. Keep an open mind and give it a real try. Happy listening and all the best.


Edited by hifuguy - 8/14/12 at 5:46pm
post #102 of 783

What are you using as your source, DAC, Amp, and transducers in your rig?
 

post #103 of 783
Wires are not capable of transmitting magic, even high end ones.

As for all USB cables sounding the same, yes that is my reality. I try to live in reality and not stray too far from it.
Edited by bigshot - 8/14/12 at 5:45pm
post #104 of 783

Hi Ultrabike, Et All,

 

Ha... well, it's a bit unusual. I should probably write it up in some other forum sometime. As I noted, I've been an audiophile for about 4 decades. But up until recently, I've never really been content and happy. Up until now, I had always took the typical approach, source (CD or DAC), amplification (preamp+amp or integrated) and then the speakers. But  no longer. I've now been very happy for quite some time with the following layout... it regularly trancends being just a good stereo and carries me away. Here's how it looks....

 

Mac Mini - Audirvana Plus Music Player SW - (then the ever-ontroversial Locus Design USB cable!) - Wyrd4Sound DAC2 - Dynaudio BM5a Monitors.

 

So, the Dynaudios are of a pro audio linage, often finding themselves in recording studios. My twist with them is that they are not on stands. Instead, I admit to stealing an the idea from Mapleshade of putting them close to the floor, on a thick maple blocks. Being kind of cheap, I made them myself. The maple blocks are brass spiked to the sub-floor with 3 long spikes. On the top front of a wooden base is a very tall fourth brass spike that tips the front of the speaker way up. The plane created by the top of the speaker crosses the top of my head in my listening position. The speakers are brought well out into the room. They don't like being near a wall. The volume control is handled by the DAC2, and its remote control. You would think that the soundstage would burry itself into the floor, but it doesn't. Instead it amazing floats up above them and is incredibly deep and wide. It's awesome. The bass is solid and lightening fast.... I think it likes the boundry reinforcement off the floor. For what it worth, I've now seen two people come over and hear it and then go out and recreate the system identically in their homes because they fell so in love with it. That's pretty high praise. It really is that good. BM5a can be found on ebay for about 700-800. Not bad for a speaker and a power amplifier! BTW, each speaker has two 50 watt power amps, one for the tweeter and one for the woofer. The crossover is done in the low-level electronics domain... rather than the usual large high-power inductors and capacitors at the drivers. Thanks for asking.... I'm so happy with it. Send me a PM if you would like to know more. I don't even think about upgrading the basic pieces anymore.

post #105 of 783

Your rig does seem fairly decent, and therefore I'm a bit surprised that you can hear differences with the Locus Design USB cable vs a regular standards compliant one. Do they provide packet error rate performance numbers vs their competitors?

 

For me, jitter is not too hard to understand. It's sort of low level FM modulated noise into a signal. I'm not that well versed on USB protocols, but from what I've read a USB receiver requires buffers and some clock recovery or re-clocking scheme (depending on USB operaton mode) to remove jitter from the chain and from the fact that data arrives in packets which need to have their control data and packet-to-packet time gaps removed. Errors resulting from jitter should be minimal if using a decent DAC with a decent USB receiver. That is why I'm a bit surprised your cable makes such a big difference.


Edited by ultrabike - 8/14/12 at 7:25pm
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