Yggdrasil A2 Measurements - Deconstructing ASR / Amir's Hack Job

Discussion in 'Source Measurements' started by purr1n, Jun 7, 2018.

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  1. ultrabike

    ultrabike Measurbator - Admin

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    Amir has some good points. The APx555 should automatically identify mis-configuration and faulty measurement setup. Then it should produce a pop up window displaying "Under-qualified Operator" and lock itself up.
     
  2. 9suns

    9suns [insert unearned title here]

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    Old news (2007) but...LMAO
    https://www.engadget.com/2007/01/20/microsoft-made-the-zune-because-partner-hardware-sucks/

    Amir: "it is time for us to roll up our sleeves and do our own hardware."

    Engadget: "And of course so they did, with great hype and great failure to immediately capture market share, the Zune was born many years later -- far too late by most accounts, but hey, you've gotta start somewhere. Still, it's funny to think that for these guys rolling up their sleeves and doing their own hardware means taking an off the shelve portable media OS (PMC 2), getting Toshiba to make a modified Gigabeat, and cutting some seriously anti-consumer deals with major labels."
     
  3. dmckean44

    dmckean44 In a Sherwood S6040CP relationship

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    He talks like my clueless boss.
     
  4. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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    Regarding Amir, wasn't he the one who also done a poor job with iFi and UpTone stuff? I don't know the guy, but on CA there were people not into his measurement work at all. This the same guy?
     
  5. Cspirou

    Cspirou They call me Sparky

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    Yeah, the same person. I don't know about his iFi work, but I dug way deeper into the Uptone drama than any reasonable person should. The stuff Alex (superdad) was saying about Amir is rather entertaining.
     
  6. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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    Yes, it is entertaining, though as a manufacturer he really shouldn't.
     
  7. ultrabike

    ultrabike Measurbator - Admin

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    Bit of cleaning done. Carry on :)
     
  8. bobsherman

    bobsherman Acquaintance

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    It also has a toilet paper roll mounted on the side of the unit, for people like the amir who are FOS.
     
  9. Ali-Pacha

    Ali-Pacha Friend

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    So much popcorn needed.

    Ali
     
  10. Elnrik

    Elnrik Super Friendly

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    Suddenly, it all makes sense.
     
  11. schiit

    schiit SchiitHead

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    Hey all, I’m going to violate my normal proscription to respond to negative PR twice (the first was earlier in this thread.) This is mainly just to say that there is good concurrence between our measurements, AtomicBob’s, Marv’s, and Jude’s.

    This is after going to Audio Precision and verifying that we were testing linearity properly, and (in Jude’s case), with the oversight of AP’s engineers.

    AP provided a bandpass linearity measurement project file for us, and also provided multiple ways of measuring to Jude, including the old-fashioned method that we used to use on the Stanfords—zooming in on the fundamental and having the analyzer run successively lower levels (-125,-126,-127,-128, etc, so on, so on).

    AtomicBob’s results, Jude’s initial results and bandpass results, and the zoomed fundamental results are available here: https://www.head-fi.org/threads/schiit-yggdrasil-v2-upgrade-technical-measurements.881867/

    Our results: https://www.head-fi.org/threads/sch...ical-measurements.881867/page-2#post-14306481
    Audio bandwidth results (Jude): https://www.head-fi.org/threads/sch...-technical-measurements.881867/#post-14306059
    Bandpass filter results (Jude): https://www.head-fi.org/threads/sch...-technical-measurements.881867/#post-14306119
    Zoomed fundamental results (Jude): https://www.head-fi.org/threads/sch...ical-measurements.881867/page-3#post-14317496

    With respect to weird measurement glitches, unusual measurements, etc—like I’ve said before, there’s something to be learned from every measurement and experience. If you’re having reproducible problems with measurement, subjective performance, or operation, please feel free to come to us and we’ll check it out, and do what it takes to make it right.

    Edited for easier access to results.
     
    Last edited: Jun 23, 2018
  12. purr1n

    purr1n Desire for betterer is endless.

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    I hate to get into this because I have a few headphones and three speakers to measure.

    One thing I'd like to mention is the misdirection being utilized by Amir. The focus on only the linearity measurements is an example of such tricks used by Amir. Why does Amir not speak of the other measurements, where his results are WAY off? This is typical of Amir, only focusing on what he wants you to see.

    There are plenty of other singled-ended measurement inconsistencies that Amir has not addressed:
    1. Frequency response
    2. FFT of 60Hz and harmonics
    3. Distortion
    I will provide an apple-to-apples comparison here of one of the above three measurements. Same SE output. Same scale. Different people. Different gear. Vastly different results. Note that I digitized Amir's plot - extracted the data from the graph.

    Yggdrasil Analog 2 THD Comparison with ASR.
    apples to apples.png

    P.S. Feel free to post this on Reddit. It's about 12 days overdue, and really, I'd rather this die.
     
    Last edited: Jun 23, 2018
  13. purr1n

    purr1n Desire for betterer is endless.

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    Here is another apples-to-apples comparison of Amir's and my results of the Yggdrasil Analog 2's frequency response. Same SE output. Same scale. Different people. Different gear. Vastly different results. Note that I digitized Amir's plot - extracted the data from the graph.

    Yggdrasil Analog 2 Frequency Response Comparison with ASR.
    apples to apples FR.png

    Seriously, I now wonder if Amir is harming Audio Precision more than Schiit.
     
    Last edited: Jun 23, 2018
  14. lm4der

    lm4der A very good sport - Friend

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    Excellent job @purr1n on preparing those apples to apples graphs!
     
  15. ultrabike

    ultrabike Measurbator - Admin

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    Last edited: Jun 23, 2018
  16. dmckean44

    dmckean44 In a Sherwood S6040CP relationship

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  17. Lyander

    Lyander Official SBAF Equitable Empathizer

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    Quick question @ultrabike, since I could maybe be missing something (emphasis mine):

    How does that make sense?
     
    Last edited: Jun 24, 2018
  18. purr1n

    purr1n Desire for betterer is endless.

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    Amir might be referring to Jude using a narrow bandpass filter to focus on the 1kHz signal for the 1kHz linearity measurement to get good results down to -140db. It's unclear what Amir really means, and he is probably doing this on purpose because if he is clear and specific, it might open up a whole can of worms on how this measurement should be conducted or how linearity should be defined.

    Amir is a good tactician and smart enough to keep away from the bloodier more technical discussions because he knows he can be destroyed by people with more knowledge. The broad strokes, the vague truths are an effective way for him to avoid scrutiny while convincing his followers that he is right. Amir cannot be wrong.
     
    Last edited: Jun 24, 2018
  19. ultrabike

    ultrabike Measurbator - Admin

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    I believe he is confused. Again. I can see linearity measurements filtering noise and distortion, which could lead to lower than -120 dB results from full scale. This IMO is valid because the measurement is concerned with the conversion levels at relatively steady state, more than with distortion and noise. In fact, depending on the measurement approach, filters and averaging may be used.

    In any case. I also don't know WTF he means by "we don't measure beyond this level". He does not measure beyond that level, but if you want to see linearity on a 24-bit part, why the hell not? This is not a SINAD or similar test. Dude probably is still stuck in thinking that he can derive some ENOB like thing from linearity. He is smoking weed.

    On the other hand, he does seem to know some shit about rank and stuff. He even knows some shit the AP guys don't . Careful, Amir's Measurement-Fu is why up there.
     
    Last edited: Jun 24, 2018
  20. purr1n

    purr1n Desire for betterer is endless.

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    And BTW, Amir's frequency response measurement: it looks like a low shelf filter was applied. Possibly wrong settings, user error, or something more nefarious???

    And notice that Amir still refuses to even discuss the MORE glaring errors in his other measurements, but continues to beat the horse to death on Jude's linearity measurement.
     
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