Raspberry Pi I2S to SPDIF Hat

Discussion in 'Digital: DACs, USB converters, decrapifiers' started by Michael Kelly, Apr 30, 2016.

  1. MrButchi

    MrButchi Gear Master Europe

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    I am interested to test XLR for AES on Yggdrasil, as well as BNC !
     
  2. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    Re-spin has not gone out. I am not sure of the value on the re-clocker since we have extremely low jitter clocks already (NDK ND2025 series). As for I2S I have a header, but u.fl could be possible. Would anyone use it, and how would they use it?

    As for the PCM512x you want PLL bypassed and master mode. That means you are using the low jitter clocks through a simple buffer that adds no jitter. Unless I am missing something? And yeah, I do sometimes get it wrong!!! :eek:

    Cheers,
    Michael
     
  3. segfault

    segfault New

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    Hi Michael,
    I'm all about the BNC, so I'd be interested in one of these boards if one is going.
    Dom
     
  4. Scott Kramer

    Scott Kramer Friend

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    was kidding!... u.fl a good way to do ext i2s, used here and there on dac's you see on diyaudio -- check out @iancanadas and others work

    nothing you need to do on the PCM5xxx... I was teasing that the hifiberry master-mode driver that these hat's utilize, has *never* utilized the MCLK completely, even when provided, and still resorting to it's internal PLL, that can be bypassed in the driver (but is not). There's some discussion going on to correct that. (with Ti themselves, allo, and the linux driver developer)
     
  5. Mban

    Mban Facebook Friend

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    I'm still interested in testing the XLR and BNC on my Yggdrasil, and have multiple different power supplies to test with the Pi and this board to let people know the influence of power supply.
     
  6. hifiandrun

    hifiandrun Almost "Made"

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    Hi Michael,
    Thanks for the update. I'd like to test the board with my Gungnir Multibit. I have a modified F-1 XMOS usb/spdif converter board which uses two CRYSTEK CCHD clocks. My mods include regulated LPS for the second section of the board (isolated from the usb +5V and ground) and better parts. I've heard people saying that the NDK clocks used on your board sound better in listening test - better midrange than those using Crysteks. would be interesting to compare them. However, I can not test XLR.
    Cheers.
     
    Last edited: Dec 7, 2016
  7. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    So what would you use for the interface? I realize not everyone has XLR as it is a bit unusual. Still, it will be one of the key marketing factors to differentiate us from Hifiberry.

    Cheers,
    Michael
     
  8. hifiandrun

    hifiandrun Almost "Made"

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    Hi Michael,
    Sorry for the confusion. At first, I thought that you referred to the RCA for the spdif coax output. Then I realized that you reffered to the on board DAC analog output. Thus I edited my previous post. As to digital outputs, I can test coaxial (both BNC and RCA) and toslink spdif - Gungnir Multibit has all those inputs. Without the XLR, i think your board would still beat the Hifiberry digi+ Pro by using better clocks and more thoughtful circuit design on separated power supplies. I currently have a Cirrus Logic audio card for Pi (using Wolfson DAC). It did not beat my F-1 usb/spdif converter with the coax spdif output due to the non-separated power supply and the single onboard clock, but it was surprisingly good. Many people believe that the usb/spdif converter is not good for streaming compared to I2S/spdif, because of the higher computing loading. To compare the "excellent" clocked usb/spdif converter and your "excellent" clocked I2S/spdif board is my main intention. I havn't found enough information on the web because people who use usb/spdif converter usually don't use linux running on a single board computer setup. My F-1 is connected to a LPS powered cubietruck running linux. I expect the I2S/spdif is the way to go.
    I would fully understand if you'd like to send the first batch to those who can test XLR. In that case, I will buy one as soon as your next production batch available.
    Cheers,
    Rong
     
  9. hifi01170

    hifi01170 Acquaintance

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    @Michael Kelly, I am interested in testing with BNC as I have bnc input on my Gungnir Multibit...
     
  10. fraggler

    fraggler A Happy & Busy Life

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    Dislike all the Randos showing up without introduction trying to get in on a prototype.
     
  11. Merrick

    Merrick A lidless ear

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    Agree. This should be for people who have been active in this thread.

    That being said, as I only have a Modi Multibit I cannot participate in the testing, but please let me know when I can buy a production board and I will happily do so!
     
  12. rallye666

    rallye666 New

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    Hi Michael, I've expressed my intention to buy the finished board via PM, but if you are looking for testers for the AES/EBU connection then I can help.

    I'd connect it up to my NAD C390dd, it has a AES input that I've always wanted to try out.

    Currently use a hifi berry digi+ for comparison purposes.

    Understand I'm very late to this thread, so obviously at the back of the queue.
     
  13. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    Obviously you are one of the "randos" fraggler was talking about! ;)

    Please don't worry guys, everyone will get a production unit. The feedback and ideas I have gotten from you all has been priceless. And the patience while I fumbled the ball on this more than once! I am going to send the digital only boards to those who have coax and/or AES XLR. I need to do this to round out the testing. But, as I said, everyone who has chimed in up to now will get a board.

    Cheers,
    Michael
     
  14. darkstar>eyesoftheworld

    darkstar>eyesoftheworld New

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    Great news! I'm not looking for a test unit, I'm just willing to buy one. I come here everyday for an update. Thank you.
     
  15. PaperStar

    PaperStar New

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    OK, I'll throw my HAT in too (no pun intended ;),
    I have a Yggdrasil and RPI (with a Digi+ for now) and would be happy to test or indeed buy a production unit.

    I'm based in the UK

    Thank you,
     
  16. WNovizar

    WNovizar Facebook Friend

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    When do you expect to finish prototyping Michael?
     
  17. zerodeefex

    zerodeefex SBAF's Imelda Marcos

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    Anyone new to the forum coming here to beg for free shit will be banned. This is retroactive and anyone who is new in here asking for free stuff (not those of you willing to buy) is getting a one week time out. I don't want people joining the board thinking they can take advantage of a vendor offer like this without either an intention to buy or being an established member.

    For the rest of you who joined just to post in this thread (@PaperStar @minio ), introduce yourself in the introductions thread before posting here.
     
    Last edited: Dec 13, 2016
  18. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    I hope I have not caused any trouble and would not want to see anyone banned because of my actions. My man reason was to in some way apologize for getting this thread going and then taking so long to finish! I value the feedback from the members and will do whatever is needed to be good citizens here. I am a bit new to all this as well! I hope that I have also been helpful with providing the thinking behind our decisions and that we are all a bit better of because of it. :)

    Cheers and Happy Holidays!

    Michael
     
  19. zerodeefex

    zerodeefex SBAF's Imelda Marcos

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    You did nothing wrong :)

    I just don't want:

    1. People to ignore the requirement of introducing yourself
    2. Folks joining with no intent to buy to get free gear to test
     
  20. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    New revs go to the PCB shop next week. I figure early January we'll have the first batch. Should be pretty solid since we are mostly cleaning up my mistakes.

    Cheers,
    Michael

    P.S. To the moderator(s) Can we offer a discount to all SBAF members without causing anyone trouble? Lurkers and contributors?
     

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