USB Cable type AB recommendation

[santhosh]

Friends,
This is a tricky subject which is why Sid is exercising caution before putting his hardearned money. And IMO he is taking the right approach. Spending (not splurging) on a well made cable will have its advantages and Sid is not investing too much into this when you see rest of his system.

I am not as experienced as some of you here, but we all know that in audio, "Hearing is believing". We have seen products with fantastic published specs, but if they don't sound great, all those specs don't matter. We don't hesitate to rubbish them. Similarly, if this experiment of Sid's defies everything that we have discussed and fetches him even 1% of improvement in the sound, I would consider it as money well spent. And if there is no improvement, atleast Sid will have peace of mind that he is not running any elcheapo component in his otherwise Hi-End system. Believe me, though my system is nowhere close to the system in question, I am often affected by the keeda (itch) to upgrade what I think might be the weak link in the chain. Afterall (IMO) audiophilia is also about psychological influence.

 

[prankey]

Friends,
This is a tricky subject which is why Sid is exercising caution before putting his hardearned money. And IMO he is taking the right approach. Spending (not splurging) on a well made cable will have its advantages and Sid is not investing too much into this when you see rest of his system.

I am not as experienced as some of you here, but we all know that in audio, "Hearing is believing". We have seen products with fantastic published specs, but if they don't sound great, all those specs don't matter. We don't hesitate to rubbish them. Similarly, if this experiment of Sid's defies everything that we have discussed and fetches him even 1% of improvement in the sound, I would consider it as money well spent. And if there is no improvement, atleast Sid will have peace of mind that he is not running any elcheapo component in his otherwise Hi-End system. Believe me, though my system is nowhere close to the system in question, I am often affected by the keeda (itch) to upgrade what I think might be the weak link in the chain. Afterall (IMO) audiophilia is also about psychological influence.

I am also like you. Looking for upgrades every possibly ways but I take money very seriously while doing so.

Now talking of getting that 1% improvement, why not spend it on a device or speakers which will definitely give you much more than that 1% improvement which is simply a myth in digital terms as he WILL most certainly get 100% same mathematical transfer what he will get by somehow passing the digital signals by directly touching the digital output or through a cable? Will a cable make difference? I have even tried a telephone cable with ultra high voltage drops to good use! Why to spend money on something which most certainly would not yield any quantifiable benefit?

Like you said, its more of an IDENTITY CRISIS what Audiophiles "suffer" from after spending so much on analog equipment which will always improve with every wise upgrade, there could be no upgrade possible to a digital one or zero (atleast theoretically)! It more of that ITCH you suggested to spend on an equally expensive digital component like you spent on a 10 Lac worth of Analog Audio equipment. I for once wouldn't hesitate using the same Rs.10 cable on those components when I own them!

 

[sidvee]

They are looking to eliminate something which MIGHT BE a jitter! Jitters can NEVER come through USB cables as per the design!


WOW! So now in search of a "better" audio experience you wish to switch from ERROR CONTROLLED 4 wire USB protocol to a completely insecured Coaxial???

While I am happy using a Rs.10 or even Rs.5 wire to somehow transfer the voltage to my AVR to recognize the PCM audio without an issue, you are essentially looking to strip the error control mechanism and take the SAME PCM audio from the coaxial output! What exactly are you trying to do other than changing audio path???

And Coaxial audio is what you are looking for, there are UMPTEEN USB Sound cards available (some very high end with excellent DACs, DSPs within which will give you Coaxial audio). Infact if I am looking for the best quality audio through a sound card, I would NEVER bother about cable, but would ensure that I use the CHEAPEST sound card without any DSP which do not resample 44.1kHz audio. Other than that, I would use the cheapest card with cheapest cable which I KNOW would work PRECISELY 100% the way it should without any error correction or any other fancy tags!



Absolutely, seems its another audiophile myth at its best! They seems to elevate themselves way beyond technology and science based on their perceptions!

Prankey - While I am not well versed with USB cables I firmly believe that coaxial belongs to the camp that is good and bad - with over 10 years of experimentation with about 7-8 dacs and about 6-7 different cables of different ranges. So I prefer to stick with what I know and hence the USB bridge.
Also in the vein of keeping this discussion friendly kindly refrain from making comments such as "WOW" etc - really does not add anything to the subject - all I am trying to do is learn and hope others are as well and as I know people prefer to do so without being ridiculed.
Also I, as everbody else is entitled to their opinion and being involved in the audio hobby for close to 2 decades I know how subjective of a field this is and only solution to that is experiencing it yourselves, and there are no absolutes.
Cheers,
Sid

 

[sidvee]

I I for once wouldn't hesitate using the same Rs.10 cable on those components when I own them!

Sorry I am not one of them and I prefer to experiment and if I hear improvement in a $1000 cable I will try to get that into my system no matter what critics or science says. And if somebody feels I am am wasting my money so be it because I also feel that the individual is losing out on musical enjoyment by not doing what his ear's are telling him - which is what this is all about.
Cheers,
Sid

 

[sidvee]

Hi Sid,
Please check with ROC on the m2tech as he uses the digital out of the M2Tech hiface -> AyonCD1S or Lyrita Pre->McCormack DNA125->Usher BE718 which is very similar to your chain especially the source part ....ofcourse yours is a AyonCD2S. I listened to his system a few weeks ago and really liked what the M2Tech->Ayon CD1S's DAC was capable of....in my very short audition.

Thanks Santhosh - I have communicated with ROC via PM and he is one amongst various hands-on (or ears-on in this case) users who report that the M2tech sounds better than running USB direct, rather than describing theoretical scenarios of which option is better or worse.
Cheers,
Sid

 

[sidvee]

Ajay124 to some extent this is true but more importantly this is the case with everything that has been reviewed in print media that depends on advertising as a form of revenue. In fact I find the car magazines quite hilarious, recommending willy-nilly,the brands advertising in them and buying a car is a significantly higher investment than audio (exceptions aside). I see the same in home improvement products, reviewed favorably in Interior magazines and you see the ads. of that product in the same or next page. I see the same in Wines, restaurants, movies, shoes, Watches - you name it, and it has a great review. How many times do you see a bad review? So as I said before, a review has to be treated strictly as a guideline, and buyer beware. Of-course there are good companies, who really have good products and one can benefit from that as well by using reviews. So I find it amazing when one hears adverse stories of snake oil in Hi/Fi & Audio (as well as deep emotional statements, arguments, disgreements etc.) only when in-fact it exists in every product that we buy based on disposable income (that has been reviewed somewhere by someone) and no one appears to be bothered with that - most of all the audiophool bashers.
Cheers,
Sid

And to add some proof to this "blah, blah, blah" of mine:lol:, for readers of Economic Times, todays ZIG wheels section has a longish review of the Ford Fiesta with the reviewer favorably reviewing the car. The review seems to be reasonably professional and if I was a novice I might buy the car based on the review alone. Unfortunately on the last page there is a Full Page ad. of the Fiesta. So guess what - this essentially is a paid advertisement by Ford in a fairly respected paper - disguised to look as if an independent expert has written it. So if I buy the car without going for a test ride, I may get lucky (and knowing Ford which is making some decent cars now that is entirely likely) or I may end up regretting a 10lac mistake till I sell the car/or even worse I may end up on car forums bashing people who went and test drove the car and didn't like it -all based on this biased review I read. Hence my position that a review, recommendation, innuendo, expert take, professional opinion, theory, thesis are all good, but one has to experience for himself/herself and then it becomes a personal and informed choice - this applies to audio as well as any other high value purchase.
BTW: I love Ford products, having owned a Ford Mustang 5.0 in the early nineties. Fun car! So no I am not dissing the car or the company, just using this to illustrate my point.
Cheers,
Sid

 

[reignofchaos]

The trouble with the Ayon's USB implementation is that the Tenor TE7022L USB converter chip used is not the greatest and the best USB chip in the world. While its okay for occasional listening, its not really meant for listening critically.

To my ears at least, the Coaxial SPDIF input sounds significantly better than the USB input. I had the Ayon CD2-s for a week and totally loved the sound through coax. However, I could not appreciate the sound I heard through USB. Of course, I was using a reasonably good quality Ridge Street Audio Poeima coaxial cable and a very generic USB cable.

Also while the CDP can do 24/192, the USB input is limited to 24/96. Not that there's much useful 24/192 content but still its kind of a downer.

 

[gobble]

I for once wouldn't hesitate using the same Rs.10 cable on those components when I own them!

This issue is very easy to resolve. Just step out and buy the cables worth 450/- 700/- from eZone or where ever and plug them in to hear the difference. I've even tried a 75ohm component cable as an audio rca.

If you don;t hear a difference then either -

1. Your system is not transparent
2. Your psych-acoustical network is "blissfully" unaware of subtleties
3. You've got that really well designed gear with system synergy of matching impedances current and voltages that makes it completely immune to cable differences.

It is possible only 10% of HiFi gear in the world falls in category 3 hence the market for voodoo black-magic cables for the rest 90% of us poor souls.

--G0bble

 

[odyssey]

Folks
I apologize in advance as I have not read all the posts on this thread - have gone through the last few .... perhaps something that is of help in clarifying the concept of jitter -

Coax or other cables don't introduce jitter, jitter is based on the quality and precision of the clocking on either end in digital transmission (Tx and Rx). The assumption here is that the in-phase and Bandwidth capabilities of the cables to carry the signal is sufficient. In the USB case - jitter is VERY MUCH POSSIBLE in the synchronous mode. To eliminate this, the asynchronous mode was introduced where in the receiver can specify when and how much of data it is ready to receive. Most of the good USB dacs nowadays have the Asynchronous mode of operation.

With regards to error control - the higher layer error control takes care of any re-transmission needed if the transferred data has error. When the USB is used for real-time streaming such as in audio, there is no re-transmission, if there are errors, they will not be corrected by any higher layer.

cheers

 

[Thad E Ginathom]

Coax or other cables don't introduce jitter

According to my reading, they can. The question is if they, in practice, actually do, and, in that case, is the receiving DAC capable of coping with the jitter, and correctly reclocking the data (where ever it comes from) if they do.

In the USB case - jitter is VERY MUCH POSSIBLE in the synchronous mode. To eliminate this, the asynchronous mode was introduced where in the receiver can specify when and how much of data it is ready to receive.

This does not make sense to me. Jitter is nothing to do with being ready/unready to receive data.

Sidvee, thanks for the details of your CD player, which I hadn't taken in before, and just went to the product page to take a look. Interesting

In general principle, I'd say that both USB and spdif are perfectly capable of delivering the data. Either may have its advantages and disadvantages, and the trouble with using both is that disadvantages may be combined. That's just my feeling: nothing scientific.

Let us say, though, that you were able to take direct USB or direct spdif from your PC to your device. The digital data arriving at the end of the cable should be the same --- but different circuitry will be involved inside the device, so I will not say that, even if exact-same data is delivered, that the resultant sound will not differ. It might.


Ahh... crossposted with reignofchaos on that...

The trouble with the Ayon's USB implementation is that the Tenor TE7022L USB converter chip used is not the greatest and the best USB chip in the world. While its okay for occasional listening, its not really meant for listening critically.

It is possible only 10% of HiFi gear in the world falls in category 3 hence the market for voodoo black-magic cables for the rest 90% of us poor souls.

That's fine for analogue.

But wait...

All our sound comes from studio recordings, with analogue and digital cable involved. Huge amounts of money get spent on the ADCs, DACs and digital recording equipment. Cablemania seems restricted to the consumer end of this relationship.

Of course, the analogue cables will, mostly, be balanced --- but I bet you won't find many crazy oak rings (or whatever) on those cables, nor will they be excessively expensive, given that they have to met specs and be tough enough for rough treatment. If consumer kit switched to balanced (but no real need to for 0.5m cable runs, of course) you'd soon see the cable companies rush to fill that market! OK call me a cynic. I am a cynic

Sure, I'll look at Stereophile and 6-moons and all those "audiophile" sites, and it's not all bad. The Stereophile article on jitter is pretty good, for instance (well, I think it is: I'm still trying to understand a lot of it! ) but semi-pro magazines like Sound on Sound (which I used to buy in UK) and the www sites that deal in pro/studio audio are just so refreshingly free of cable-company induced manias. They are my first port of call for sound cards and associated computer/digital/audio stuff.

 

[gobble]

That's fine for analogue.

But wait...

All our sound comes from studio recordings, with analogue and digital cable involved. Huge amounts of money get spent on the ADCs, DACs and digital recording equipment. Cablemania seems restricted to the consumer end of this relationship.

Maybe thats because the work item or finished product of a studio is a digital master copy to be published on CD and not the analog side of listening pleasure or enjoyment?
Like your article said, jitter does not affect digital to digital copies. They would spend on ADC related accessories though I am sure.

--G0bble

 

[sidvee]

In general principle, I'd say that both USB and spdif are perfectly capable of delivering the data. Either may have its advantages and disadvantages, and the trouble with using both is that disadvantages may be combined. That's just my feeling: nothing scientific.

I'm with you on that Thad - but what I understand having interacted with various users, the USB bridge was expressly introduced to mitigate the effect of synchronous jitter issues, wherein the bridge has an anychronous USB implementation that takes care of this. Now being a novice in this area and technologically impaired or disadvantaged (hope this is the politically right term:lol at the best of times, I normally would listen to the device and let my ear's be the judge, which I did in this case and found that with the the device in the chain, the sound was indistinguishable from regular cd playback. This tells me that the bridge is working as advertised. Of-course now my shiny new Ayon Cd2s that cost me a large amount of money should have a similar implementation in its USb input, but apparently not, I kind of suspected before buying but it offers a host of other benefits that outweigh this - I will test it out myself as well to convince myself.
Anyways as I have summarized my position before I am willing to experiment and spend money on both a decent USB cable and a USB bridge and let my ears tell me which is better. I hope no one would begrudge me for considering this rather logical route.
BTW - No flames/ridicule/sarcasm/supercilious comments please - I am reporting what I heard - whether good, bad, ugly or technologically impairedhyeah:
Cheers,
Sid

 

[odyssey]

Thad
In a synchronous clocking system both the transmitter and the receiver need to be working at the same clocking freq and phase to ensure the right delivery of data. In telecom circuits where the frequencies tend to be higher, this is achieved by synchronizing the Tx and Rx ends to the same Master clock reference (usually an expensive piece of equipment). Similarly, high end CDPs such as DCS accomplish this by a separate external clock connected to the various components within the stack. This is all in a synchronous system where data transmission is taking place in a pre-determined time slot. Jitter takes place since the timing of the receiver is off wrt to the Tx. Your coax connection works this way. The cable cannot add jitter if its high bandwidth and if it preserves phase among various frequencies that it transmits (meaning one does not arrive earlier than the other). Its not the cable but the synchronous clocking system that adds jitter (due to clock shifts on either end).

So in laymans terms think of it this way - there is a train with 10 bogies from Station A to B. Both ends are in no position to identify the bogey except by time of arrival at a particular point at the receiver end. So the receiver is set to think that each bogey comes in at every 10 seconds. so bogey 1 at 10s, bogey2 at 10 sec, etc.
Over time, the Rx and Tx lose the clock synchronization, so the Rx can end up thinking that its seeing bogey 2 when its actually seeing bogey 3

In an asynchronous system, the receiver asks for the Tx to send data and knows exactly when to expect it and in what format - so its closer to saying that the Rx knows how to identify a bogey and it does not just depend on its own clock.

cheers

 

[Thad E Ginathom]

Oddysey, I still think you have some confusion between jitter and buffering and a misunderstanding of jitter.

Sidvee, I can go with your experience, and the explanation of it given by you and reignofchaos, and even guessed at by myself, with no problem at all.

 

[odyssey]

what is the confusion ?
A jitter buffer can be used to mitigate the effects of jitter. I don't know what your background is but if you understand the concept of synchronous clocking, or asynchronous timing the concept is pretty simple to understand. In fact, this is fundamental concept, you should google and check it out, there will be many explanations which will be simple to understand
Cheers

 

[Thad E Ginathom]

Jitter has played quite a large part in our discussions over the last hundred-plus posts. Do please read the thread, and you will find that, give or take a little controversy (mostly over whether it matters or not, rather than over what it is), we have understood it.

I do not deny that the word may be used in more than one way. However, jitter, in this context, is the mistiming of individual bits, which this get read at incorrect values, and not the dropping, changing of order, or mis-identification of samples. (OK, my understanding is still vague, but I know I am in the right area.)

Please check back again through the thread. There are several useful links. The Stereophile article is the most technical (and I have not succeeded in taking it all in yet) but others, such as Sound on Sound link are more easy to digest.

Please see the quote and article linked to in my post 55. That is jitter as we are discussing it. You are talking about something else: the confusion is all yours!

Please note particularly:

Another source of jitter (the strongest source these days) is cable-induced. If you pass digital signals down a long cable (or fibre), the nice square-wave signals that enter degrade into something that looks more like shark fins at the other end, with slowed rise and fall times. This is caused by the cable's capacitance (or the fibre's internal light dispersion), so the longer the cable, the worse the degradation becomes. That's why digital cables need to be wide-bandwidth, low-capacitance types.

Coax or other cables don't introduce jitter
cheers

(My bold) Your confusion, I think.

 

[hydra]

So in laymans terms think of it this way - there is a train with 10 bogies from Station A to B. Both ends are in no position to identify the bogey except by time of arrival at a particular point at the receiver end. So the receiver is set to think that each bogey comes in at every 10 seconds. so bogey 1 at 10s, bogey2 at 10 sec, etc.
Over time, the Rx and Tx lose the clock synchronization, so the Rx can end up thinking that its seeing bogey 2 when its actually seeing bogey 3

I do not deny that the word may be used in more than one way. However, jitter, in this context, is the mistiming of individual bits, which this get read at incorrect values, and not the dropping, changing of order, or mis-identification of samples. (OK, my understanding is still vague, but I know I am in the right area.)

@Thad, I think Odyssey's explanation is fine. I don't think he meant that the clock (Rx) was mis-identifying the samples.

In his example, if the timing were perfect, the Rx would be expecting to see Bogey 2 at a given point in time. But, because of the timing error (= Jitter), the Rx would actually be seeing Bogey 3 instead of Bogey 2 at that given point of time.

This is what I understood from the explanation. I could be wrong too, and I'd love to know what the right way to look at that explanation is: I'm not too sharp on exactly what Jitter is either

 

[Thad E Ginathom]

There is always a chance that I have misread!

But (and I do like a good analogy!) what seems wrong to me is thinking that bogey 2 is bogey 3. As per the articles we have discussed, the error is in thinking that bogey 2 is in the station, when it is only half in the station. This (straining the analogy, sorry) if it is the number of windows that matters to us, we misread. because we only see what has reached the platform, and not the part that hasn't.

I think Odyssey may be talking about principles and practice that apply to telecoms rather than to the particular methods of audio transfer that we are discussing here. He mentions packet switching.

Apart from that, his comment about cables appears to be wrong.... Although, if he meant to say that properly specified and manufactured cables do not induce jitter then I'd have no problem.

Have I got the wrong end of the stick (every stick has two ends, a wise man once said, but too early in history to label them 0 and 1)? I don't think so ... but it'll all come out in the wash, as they say . Sure, I'm as stubborn as a donkey, and I'll stick to my guns, but if it turns out I have to eat my words, then pass the plate!

 

[gobble]

All the discussion about jitter is pointless unless we arrive at a figure or value about how much timing precision is required. Since our perception of time below 500microsecs is bound to be very poor, we can get into endless arguments because we do not know if the other person is taking 100microsec as a benchmark or 100millisec or 100 nanosec? A person might argue vociferously taking 100nanosec jitter as an absolutely minuscule unit of time to be audible to human perception ( an thus argue a 3ft cable and its surrounding EMI cannot induce significant jitter) while the opposing person may scoff at him with a personal benchmark of 200 picoseconds mattering to SQ.

The following researchers article establishes 173 picoseconds as a benchmark for 44.1khz/16bit beyond which jitter will have audible impact on a keen listener. It goes down further to 1.35ps for 8x oversampled 20bit audio stream.

I am too lazy to follow the math, and I dont find many peer reviewed articles on this assertion as well. But perhaps the Ph.D folks on this forum can spend some personal time and validate if it looks good.

kusunoki

--G0bble

 

[Thad E Ginathom]

All the discussion about jitter is pointless unless we arrive at a figure or value about how much timing precision is required.

And even more pointless if we can't decide what it is!

But you are right. I cannot cope, mentally, with anything smaller than milli-seconds, and they can get quite noticable, because a dropout of 250 of them (one whole quarter of a second) would be massive to the ear. In fact, I wonder how many milliseconds a small scratch on vinyl takes: not very many, I would think?

Once we get to picoseconds, I'm not even sure how many zeros are involved without looking it up.

A person might argue vociferously taking 100nanosec jitter

And they might be right, even if one event of 100 nano-seconds would be undetectable to the ear, it is, apparently, the artifacts created by jitter that are audible, not the jitter (as such) itself. Duuuh... I guess none of us listen to music bit by bit!

A person might argue vociferously taking 100nanosec jitter as an absolutely minuscule unit of time to be audible to human perception while the opposing person may scoff at him with a personal benchmark of 200 picoseconds mattering to SQ.

And a third will say that the equipment takes care of it and reclocks it anyway!hyeah:

What we need is examples. Actual sound samples with known amounts of jitter. Yes, I know they'd be going through the ADC/digital/DAC cycle again, but it would be better than nothing. Let's google...

EDIT: I googled, and got distracted by this article

In this article we try to give the final word on this so discussed topic.

So it's got to be worth reading, yes? I'm reading... :yahoo:

And, well, yes, uh, final... I should better honestly say from the beginning that I am not sure we have full success....

Oh well, I'm still reading hyeah: