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Thread: Science Thread: Review of Audioquest Jitterbug and Uptone Regen USB Conditioners

  1. #51
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    Quote Originally Posted by mansr View Post
    The Regen is small enough that it can easily be placed very close to the DAC, so there's that. Once might also suppose that even a bad cable from Regen to DAC, starting out with a clean signal, would be better than the same cable starting out with a dirty signal directly from the computer.
    Fair enough. In the few minutes before I pack and go to RMAF, I ran a quick test of short versus long cable feeding the Regen. The short cable was what came in REGEN box. Long cable was a Belden I was using with my Audiophilleo USB to S/PDIF bridge. Here are the results:


    As we see, nothing changed. Don't mind the small shifts. Those are variations in the measurement from run to run.

    This is what I would expect because the function of this device is to regenerate the USB bus with its own power. If it were very different, I would wonder what it is doing.

    Appreciate the comment and question .

  2. #52
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    Quote Originally Posted by amirm View Post
    (...) We created this subforum to be free of this kind of commentary. I on purpose put the word "science thread" in the title. I put a note in there saying to not come here and say but your ears say this and that. Despite all of this, we get posts like this.
    Amir,

    We should respect your wishes. However, as YOU posted what your ears say, I felt free to comment to a question on your comment. Considering your expertise and the high sound quality of the equipment you deal with, the comments on what you reported to have heard can not be ignored. Just MHO.
    DCS Vivaldi 2.0 stack, Soundlab A1 Px's while waiting for the XLF successor, EMT927, SME3012R, ARC Phono 3, Lamm ML1.2 Ref, Lamm L2ref, Stealth Dream speaker , Crystal Dreamline ICs, TA XL digital, TA XL gen V power cables, CenterStage footers and Nordost Qkore8's!

  3. #53
    Quote Originally Posted by Antoine View Post
    The number of positive reports (about the Regen) is just too big, feedback too unanimous/similar in contents for it to be powerful bias alone (to me).
    Is it though? I suspect there might be a fairly strong selection bias in favour of positive reports.

  4. #54
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    Of course I can't prove it with 'hard numbers' (already said myself it's mainly anecdotal) but anyone can form their opinion regarding this subject by reading the many feedback threads/discussion threads on the Internet. The biggest number of reports can be found on the Computer Audiophile forum.

  5. #55
    The number of positive reports (about the Regen) is just too big, feedback too unanimous/similar in contents for it to be powerful bias alone (to me).
    Well, the heart of expectation bias is expectation. If it hasn't been created, it won't be expected. Your argument works both ways. And too many positive reports? How many is that in the audiophile forum world? 25? 50? Not many at all, and given the nature of expectation bias, the more there are, the more there are likely to be, even if the difference is non-existent (or noise and distortion).

    In any case, this is a variation of the "I hear it, therefore it is," argument. It holds no water in a science thread.

    Tim
    In high-end audio, you can't even fight an opinion with the facts.

  6. #56
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    Quote Originally Posted by Phelonious Ponk View Post
    Well, the heart of expectation bias is expectation. If it hasn't been created, it won't be expected. Your argument works both ways. And too many positive reports? How many is that in the audiophile forum world? 25? 50? Not many at all, and given the nature of expectation bias, the more there are, the more there are likely to be, even if the difference is non-existent (or noise and distortion).

    In any case, this is a variation of the "I hear it, therefore it is," argument. It holds no water in a science thread.

    Tim
    +1

    Amir, The anti-science voices are being allowed to go to far outside the rules here.
    TIA

  7. #57
    Quote Originally Posted by Phelonious Ponk View Post
    Well, the heart of expectation bias is expectation. If it hasn't been created, it won't be expected. Your argument works both ways. And too many positive reports? How many is that in the audiophile forum world? 25? 50? Not many at all, and given the nature of expectation bias, the more there are, the more there are likely to be, even if the difference is non-existent (or noise and distortion).

    In any case, this is a variation of the "I hear it, therefore it is," argument. It holds no water in a science thread.

    Tim
    Well here is some hard data for you:
    a) The $175 REGEN is sold with a 30-day, money-back, satisfaction guarantee;
    b) To-date we have sold 1,723 units;
    c) Exactly 8 people have asked for a received a refund on their purchase. That is less than 0.5%.

    -Alex Crespi, UpTone Audio LLC

  8. #58
    Hello, Amir, I think you may have things turned around a bit with respect to the cables. The supplied solid adapter between Regen and DAC is supposed to work better than the supplied short cable, both according to Alex and John and by listeners' reports. The short cable is supplied in case the solid adapter can't be used for some reason. The effect of the cable between computer and Regen is supposed to be reduced relative to (any) effects of cables without the Regen.

    I have no idea at all whether tests with the solid adapter would show any difference, but am curious whether it might.

  9. #59
    Quote Originally Posted by mansr View Post
    Is it though? I suspect there might be a fairly strong selection bias in favour of positive reports.
    There could well be. Still, I don't think talk of bias is any more germane than mention of positive reports in this thread. I await further test data with interest and curiosity.

  10. #60
    Quote Originally Posted by amirm View Post
    My mission was to verify the technical aspects of the product. It said it cleaned up the USB signal, ergo it cleans up the output of the DAC. That didn't turn out to be the case.

    In a science thread I am not digging deeper in this area. We are here to discuss the objective data which cannot be doubted as easily as what I did or did not hear.</i>
    I did not find your work an adequate scientific study for two reasons:

    1. The "mission" is not broken down into separate questions, namely: (a) does the device (e.g. REGEN) improve the USB signal integrity? and (b) does this affect/improve the analog output of the DAC?

    (a) For me a scientific study would have required lab quality USB measurement equipment used. Measurements should have been performed to characterize the USB signal quality of a variety of computer sources, involving a variety of computer hardware, computer software and USB cables.

    (b) For me a scientific study would require a wide range of USB DACs, including those at a wide range of price points, together with comparisons of input waveforms (with and without the REGEN) and output waveforms. In addition the tests should have been formulated to avoid ambiguities, such as the ambiguity of the Jtest signals at 8 and 16 kHz being jitter vs. harmonics. There are enough variables involved that a range of test conditions are needed before it is possible to evaluate any cause-effect relationships. There was no experimental design or possibility of statistical analysis with the small sample of gear tested.

    I doubt I could have done any better. I don't have a hardware lab, let alone one costing six figures. But without the appropriate equipment and appropriate test methodology I would be forced to dabble, not do science.

    This may be a matter of personal style, but given the results you obtained with what is at best a preliminary investigation, I would not have published your measurements, as it is too easy to interpret them as denigrating a well regarded product. Had they been positive, then I would have been inclined to publish the results as preliminary measurements, but not make any attempt to justify that one is doing any kind of science, or even engineering. What you did strikes me as more appropriately a case of a technician doing preliminary testing of equipment to scope out if it is working, prior to any serious work being done.
    Last edited by Tony Lauck; 09-29-2015 at 12:36 PM.

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