MD x Airist x Sosolar: RDAC design mysteries

Discussion in 'Digital: DACs, USB converters, decrapifiers' started by bimmer100, Jun 5, 2018.

  1. Senorx12562

    Senorx12562 Case of the mondays

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    What I'm lacking is $555. But if I had it I would jump on the 1321.
     
  2. Dzerh

    Dzerh Friend

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    sub 10ps, -150db ... are you sure you making audio DAC for listening? not some lab measurement device? :)
     
  3. sosolar

    sosolar Hibiki DAC Designer

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    Nobody complains better spec, right?:punk:
     
  4. soekris

    soekris MOT - Soekris Engineering

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    No, just not understanding noise specs.... Noise always have to be qualified with bandwidth, normally with audio it's 20 hz to 20 Khz.... I say 129 dB unweighted (A-weighted is 3 dB better) at 20 hz to 20 Khz with my modules, basically the resistor noise.... But if I used a narrow enough FFT, averaged over long time, I could also say 160 dB as there is where the bottom line is on the FFT, but it is not a real spec.... It irritate me that people / companies throw out those high number, as they by themselves are completely useless....
     
  5. ald0s

    ald0s Facebook Friend

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    @soekris I appreciate that you are a talented designer and bring more to the forum than I do, but all you have done in this thread is shill your own stuff, put down other equipment and imply to massdrop consultants here that you're willing to be picked up. This thread is not about Soekris.
     
  6. soekris

    soekris MOT - Soekris Engineering

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    Like other people here I'm having fun seeing how this is developing, and trying to correct errors when I see them....
     
  7. sosolar

    sosolar Hibiki DAC Designer

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    Thank you for correcting me. I need to clarify that it is measuring the output of power supply module, feeding to audio analyzer then read FFT result. The spec I mentioned is -150dB@1kHz and further(more likely it is measuring noise floor of my analyzer). 1/f is much lower, means we got that level much earlier than I quoted. Resulting to much purer and deeper bass performance.
    Regarding to triggering phase noise, -120dbc/hzsqrt and -140dbc/hzsqrt is measured at 1k and further. And for PLL, 100ps is based on datasheet presuming that it is cycle-cycle RMS jitter. sub-10ps is based on datasheet with reasonable worse case form 10Hz-1MHz.
    Sorry for my laziness that I skipped that important info.:(
     
  8. Jinxy245

    Jinxy245 Vegan Puss

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    I can understand your reading it this way, but I think it might be helpful to keep in mind a couple of points.

    Since @soekris is a designer himself, he is usually going to speak from his own experience, so if he's talking about "my boards" it's not plugging his wares so much as talking about what he's done. (He did call himself out on plugging his stuff previously)

    Also, I have to admit I'm not able to keep up with the technical aspects of these posts (perhaps you do, in which case, kudos) but it's seems quite relevant to point out discrepancies, if they're discovered. If Soren is off in his points, there are plenty of experienced members here that will call him on it.

    Finally, I could be wrong about this, but I don't believe English is his 1st language, so he might be some info lost in translation.

    Like everyone else watching this thread, I'm curious how this plays out, and I think @sosolar has answered these questions well. I'm looking forward to learning more.
     
  9. purr1n

    purr1n Desire for betterer is endless.

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    @sosolar has been super gracious. It's a fine line, for example, one MOT posting measurements of another MOT's product with commentary would be inappropriate though! As long as people behave well, it's fine. I just don't want this place turning into Computer Audiophile where vendors are at each other's throats.
     
  10. Dzerh

    Dzerh Friend

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  11. drfindley

    drfindley Secretly lives in the Analog Room - Friend

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    VINDICATION!!!

    (Please ignore my digital, though honestly I paid for most of that)
     
  12. sosolar

    sosolar Hibiki DAC Designer

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    UPDATE:
    I replied a message to Will yesterday talking about my detailed design timeline picture by picture from 2015 until now, my personal preference unnecessary design such as big transistor, buffer opamps, logic switches and the request of their prototype pictures in timeline form.

    Today, Will reply talking irrelevant topic i.e. r2r topology in Chinese forum(glad to know they are still with Airist), and refused my request saying that they dont have any picture to prove they was designing the same as mine.


    He is trying to pasuade me that they have done the same thing in the same form without any proof, denying the fact. However, not every customer will believe your story, but quickly drain your hard-earned reputation.
     
  13. Senorx12562

    Senorx12562 Case of the mondays

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    As far as I know, Airist's reputation was as a company that made an amp no one liked, so their reputation can't be hurt too much with us. But I am sure most here would like to know the truth about this whole story prior to purchasing either product.

    Edit: Ok, zeos liked it.
     
  14. sosolar

    sosolar Hibiki DAC Designer

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    I mean...Massdrop is losing their reputation.
     
  15. Senorx12562

    Senorx12562 Case of the mondays

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    Not with me without knowing more facts. Considerably more. But that's just me.
     
  16. bilboda

    bilboda Florida boomer

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    At this point, their whole involvement is suspect. Why would they contact Airist regarding a r2r dac in the first place? Airist does not design dacs. Why not contact Hasbro or some other non-dac company?
    My guess is Airist had contacts which means the whole endeavor was a consultancy. Who is the supposed actual designer? What is his pedigree? It is not surprising that the best thing they could come up with is somebody else's board as they have no one , consultant or not, who is capable of designing one.
    So at what point did they become complicit in using a board that they apparently feel is open source? They are certainly aware of it now and from Will on down are doing abysmally in backing down from their open theft.

    There is no room for mealy mouthed excuses. This is what it is. If someone is willing to accept their drivel of excuses and at this point, obvious outright lies, that's probably only because they want a cheap dac. Money talks and bs is making the walk here too. The Cavalli amp and Grace dacs are obviously legit. This is obviously not. I am queasy about aligning with a bully here. We are all free to choose our own path (Westworld)
     
  17. Thad E Ginathom

    Thad E Ginathom Friend

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    Can't this be settled face to face? Oh wait... ok, several thousands of miles might be in the way. But all we have so far is the photographs of one side of one board, with everybody talking about other things being the same or different. Isn't time we, or more especially, the concerned parties, actually showed something to each other? Am I being naive to think it is that simple?

    OK, everybody is paranoid about intellectual property, nobody wants spying eyes on their new release, but hey, this is not some top secret device embedded in a compound that can't be seen through, it is a box of electronics, which the curious will remove the covers of, sod the warranty, on day one.

    Can't people just look and see? Or agree to a trusted third party doing so?

    I can sympathise with any manufacturer throwing trivial and fatuous claims straight in the bin, but this seems serious enough for Massdrop to have a serious concern on showing that all is clear. Or finding out that it isn't and doing the necessary. It goes beyond asking people who ask people who say that it's ok and repeating that it's ok.
     
  18. Kattefjaes

    Kattefjaes Mostly Harmless

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    This might be the only way I'll ever get close to the 1%, then. The only stuff in my collection that wasn't bought are a few soundboard recordings/bootlegs. There's a little bit of "not for sale" stuff that I picked up at record fairs, and some unlicensed remixes too. However, I can cheerfully say that if any of these were issued commercially, I'd snap them up, assuming they hadn't ruined the sound with harsh remastering.

    I don't know that I can lay claim to any sort of angelic ethics, I just never feel like I "have" the music unless it's a legit copy.
     
    Last edited: Jun 9, 2018
  19. Thad E Ginathom

    Thad E Ginathom Friend

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    Most but far from all of my music is "mine." Not sure about the law, but I feel ok about the ethics of "obtaining" digital copies of stuff where I own the vinyl. I used to do my own ripping, but ears and patience ran out. I will not pay music companies multiple times for the same thing.

    My respect for music copyright went downhill steeply when a major label, right at the end of the transaction, refused to sell me, at quite a high price, a collection of albums, because of where I live. They lost the money and I found out about torrents. It was an act of defiance, but I confess it was not the last time.
     
  20. frenchbat

    frenchbat Almost "Made"

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    Let's not confuse things and put illegal download for personal use, at the same level as (alleged) product copy and profiteering.

    That's like putting shooting someone for self defense at the same level as school shootings. I don't think that would bring anything really useful to the debate.
     

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