Why do USB cables make such a difference?

Discussion in 'Sound Science' started by Cartma, Jul 17, 2017.
  1. gregorio
    1. As I see it, what you are suggesting effectively covers not only an extreme situation but a number of simultaneous extreme situations, which are necessary to achieve achieve transparency to the levels you're talking about. How many consumers are trained to the level of a Harman trained listener, how many of those also have an exceptional monitoring equipment/environment in their homes, how many of those who remain are listening to content where such levels of noise is actually achieved and how many of those routinely listen at levels higher than intended? Unless someone is specifically testing for noise levels rather than just listening for entertainment, it's possible that the number of "those" who remain is zero or if there are some, they are certainly outliers. I understand that as an equipment engineer you ideally want to cover all possible eventualities and all the above conditions certainly are possible, just very unlikely. As a content creator I typically have to deliberately ignore "those" remaining people (outliers), because catering to them is often impractical AND undesirable, as it would compromise the enjoyment for everyone else (the target audience).
    2. This statement brings us right back to the question I've raised several times, which you refuse to address! I entirely agree with your statement, that with "little to no price premium" it is possible to achieve even your "all encompassing channel transparency" and that we should "rally around" the companies who achieve this "engineering excellence". BUT, what about those companies who achieve that "all encompassing channel transparency" but at vastly higher price premiums, with marketing stating/implying that such a vast price premium is required to achieve such audible transparency, should we also "rally around" these companies or should we not attempt to debunk their marketing and over-charging?
    3. I don't see bigshot as saying no one should care. I've had my run-ins with bigshot in the past but he's entitled to say that for him, a DAC beyond say -80dB makes no difference and is therefore not worth caring about. At least he's thought about it, which is more than most do. It's also entirely possible that for the majority (probably even the vast majority) of consumers with their listening skills and usual consumption habits, that he's absolutely right. I prefer to cover more eventualities and feel safer quoting a figure of -100dB or so, while you want to cover all possible eventualities and quote -120dB. All three of us are entitled to these opinions here, as all three of us have justifiable reasoning for those opinions but, each of these opinions also have reasonable counter arguments (except mine of course, because I'm right and you're both wrong!) :)

    Last edited: Nov 10, 2017
  2. castleofargh Contributor
    I thought only mothers were always right? do I need to revise my criteria about truth? ^_^
  3. Whazzzup
    So no thoughts on this ferrite stuff improving USB. I personally smell something fowl, but won’t knock anyone trying anything.
  4. castleofargh Contributor
    ferrite has been addressed in this topic and others, and is a simple enough component for you to read its electrical effect and judge for yourself how much it can contribute. it's a low pass filter of sort, so where it starts rolling off matter more than the ferrite or no ferrite question. but then again black and white views about anything are usually wrong. no reason even for such a simple component to escape the audiophile dumbification of electrical properties.
  5. Whazzzup
  6. SilverEars
    Only thing I really care about is the ground loop heard out of my dirty desktop(it's a filth of noise). I was thinking about getting a usb isolator, but high speed ones are to expensive to be worth it, but also I looked into a usb to opto interface types, and they all seem to be limited in bit rate as well. I'm looking for cheap options that can go up to 192khz for optical, but unfortunately I don't find them or possibly pricey. I looked at Monoprice, but hard to navigate to find one.

    Not sure if ferrite bead is the solution for this. I think the most economical option is to get a cheap sound card that has optical out(for some reason, stupids didn't include optical on my motherboard).

    I guess either a cheap soundcard or Schiit Wyrd, which does have high bit rate throughput(significantly lower priced than others I've seen for high speed). Cheap soundcard with optical out, or Wyrd that decraptifies the usb noise?

    I think one should listen, and if there is no ground loop heard(anything odd heard), it's fine.
    Last edited: Nov 11, 2017
  7. Darren G
    There are a couple of of ground loop solutions I've tried. It is still cheaper to try plugging all equipment into the same ground, but if that is not possible..

    The Intona USB solution supports USB 2.0 speeds, and will break a ground loop. Cheaper solution is the Schitt Eitr, USB in, Coax out. The former uses optical isolation, the later transformer isolation.
  8. SilverEars
    I need optical out, not coaxial. Intona is the one that costs multitude more expensive than Schiit Wyrd for high speed. Perhaps there is a cheap DIY high speed usb isolator?
  9. amirm
    Definitely not. Ferrites increase the impedance of the cable, making it a better high frequency filter. But for vast majority of them, the effect starts at 1 Mhz (1000 Khz) and above. You have to get pretty fancy to get below 100 Khz so no chance at all that they will do anything with 50 or 60 Hz hum. Indeed ferrite core manufactures don't even spec what happens below 1 Mhz as this example from Murrata (one of the main manufacturers of magnetic products) shows:


    Notice how the x axis starts at 1 Mhz. The reason manufacturers use them is because of needing to pass regulatory tests. In this case, "conducted emissions" which start at 1 Mhz are of concern due to length of the wire acting like an antenna.

    The best solution is to use balanced interconnects if you have that option. If you can't do that, you can use a Jensen transformer. Or track down the source of ground loop.
    SilverEars likes this.
  10. amirm
    I already explained all of this. Refer to how a random person working for one of our partner companies could beat me despite my years of training. And oh, my testing is done with just my headphones plugged into my HP laptop. They are nice headphones (Etymotic E4RS IEMs) but nothing exotic. And that is a key thing: you are in a headphone forum. Headphones block outside noise exceptionally well and allow one to get to very high levels of listening. Almost all lossy codec testing is done with headphones for this reason. So if there are warts, they are far more liable to be heard among the audience of this forum than elsewhere. Look at how many people complain about noise in amplifiers here vs broader set of audiophiles using speakers.

    So there is nothing extreme here. If I can hear it with ordinary IEMs and a laptop, it is a bar too low.

    The answer to that is continuing to perform independent measurements to see if they are or are not overcharging. Sitting here, I am disappointed in my purchase of Exasound E32 which retails for $3,500. See my review here and how I don't suggest people buying it: https://audiosciencereview.com/foru...xasound-e32-dac-review-and-measurements.1990/

    We don't get there by what started this argument: that we shouldn't bother measuring. It is measuring that tells us if we are overcharged for performance or not.

    Heck there are high-end products that actually perform worse. Again, it is through measurements that we get that information.

    He didn't just say that. He said it in response to the work I put in to make these measurements, adding FUD to the data. He can speak for himself but he has done the opposite here. I just can't get behind someone who prefers to see less data than more. And wants to dumb down quality as to win recognition on forums. I value excellence and execution and the notion that he doesn't care so other should not doesn't sit well with me. Nor is it a service to the community. We need to weed out the good and bad. Then we have data to make an informed decision.
  11. bigshot
    There's no lack of tests and measurements and scientific papers around here. The thing that is lacking the most in audiophile forums is perspective. No one ever puts the specs in the context of listening to music in the home. They point to measurements and listening tests conducted in anechoic chambers with tones as if those are the benchmark needed for a home stereo system. That's totally wrong. The benchmark is REAL human ears in a REAL living room with REAL music. Going to extreme means to extend specs further into the realm of the theoretical is like a big neon arrow with a sign that says "Rabbit Hole This Way ---->". Me pointing that out isn't "dumbing down" anything. It's a hell of a lot more helpful than if I tried to convince people to trust my opinions because I have super human hearing and I work very hard at conducting tests of how equipment performs in extreme theoretical conditions. People want to know what headphones or amp they should buy. That doesn't require splitting atoms. It just requires defining the purpose in which the equipment will be used for to determine how good is good enough. If you want to keep calculating pi out to the 10,000th decimal, feel free to do that. Yes, it's a lot of work. But it isn't helping anyone. Being disingenuous about how you conduct your tests pushes it beyond not being helpful into being distinctly unhelpful.
    Last edited: Nov 11, 2017
  12. castleofargh Contributor
    I very much disagree. ^_^
    amirm likes this.
  13. bigshot
  14. amirm
    You have to buy those papers or become a member like I am. As such, what is there is inaccessible to membership for the most part. Worse yet, those papers are written for other researchers and engineers in the industry. As such, understanding them can be quite challenging.
  15. amirm
    First of all, these are not "specs" we are talking about. They are measurements. Specs are what manufacturers put out, often with no testing to verify them.

    And in those measurements, I absolutely comment on audibility. Here is an example of Teac NT-503 measurments: https://www.audiosciencereview.com/...asurements-of-teac-nt-503-networked-dac.2028/

    "Listening Tests: Unbalanced Line Out:
    For this test, I used my Stax SRM-007t. I used this because it has dual inputs and allows me to make very fast AB switching. I then used Roon and ganged the NT-503 and Exasound and then NT-503 and Topping into zones. The outcome was synchronized playback on both devices at the same time. Boy do I love Roon! :)

    Testing first against the Exasound, I could not detect any difference. Both the Exasound E32 and Teac NT-503 produced delightful sound. Gone was what I was hearing with headphones. Alas, the Exasound drivers are quite fragile and just after a few clips, it refused to initialize no matter how many times I restarted Roon, Exasound or plugging and unplugging the USB cable. :frowning2: The Teac was also flakey until I put it in non-event driven mode in which it became much more reliable So all in all, this testing was cut short but I stand behind the outcome.

    Testing against the Topping D30 resulted in tiny preference in favor of Topping D30. Alas, its output is also 1 or 2 db higher and I think that is what I was hearing. Longer term I will do more level matched testing. Outside of that tiny difference, again both were delightful to listen to. Indeed I am doing that as I type this and would be happy with either device playing my reference playlist."​

    So perspective is clearly demonstrated yet you keep complaining and talk about issues that are not at all in play here. Knowing everything I know, when I say something is poorly engineered, it is. That is data and people need to know that and shift their buying decisions to people who care about creating good performance. Throwing dust in the eyes of readers and people who work to produce data versus yourself just sitting on the sidelines is not correct.

    From what I have seen, vast majority of these companies have never tested their products with professional measurement equipment. This is why there are so many surprised in what they produce. This data needs to get out there as to encourage better designs in the future. I have already seen companies change their designs and one even discontinue it based on what I have uncovered in my measurements and review.

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