Raspberry Pi I2S to SPDIF Hat

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

  1. lehmanhill

    lehmanhill Almost "Made"

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    I did find other 24/96 files and they crash the player too. So far, I haven't been able to read the logs because the player won't connect with logging turned on. It is looking more like a software issue. I will try reformatting the SD and a fresh download of PCP to see if I can solve the problem.

    In the meantime, my friend resampled the files to 16/44 and they worked, so I have been able to evaluate the files as asked.

    Thanks all.
     
  2. earnmyturns

    earnmyturns Smartest friend

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    Two i2S questions:
    1. What's the top I2S sample rate? I suspect 192k from reading the reference manual, but it's not exlicit.
    2. There was a planned HDMI adapter for PS Audio-like pinouts (like on Holo Spring DACs). News on that?
    Thank you!
     
    Last edited: Feb 5, 2021
  3. stevej

    stevej New

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    Is this to power both the PI and PI2AES? If so what PSU did you use and how long were you able to use it this way without any sign of damage to the boards? I’m considering something similiar with my allo Shanti 5v 3amp LPS but want to make sure it doesn’t cause any damage to the boards.
     
  4. Clemmaster

    Clemmaster Friend

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    For several months with the LPS-1.2, until it died and took the PI2AES with it!! :rolleyes::mad:

    I knew the risk, I lost.
     
  5. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    192 khz is indeed the maximum that the wm8804 AES transmitter can operate at but, that also happens to be the maximum that the raspberry pi i2s port can operate at, so it all works out.

    I have the pcbs for the PS audio adapter, but I found out last week that my part-time assembly technician is not coming back from covid quarantine. Not a health thing, but I guess it was enough of a scare to make them stay at home.

    I was using this person to build small runs of protos and they were in line to do the adapter. I'm going to have them built by an assembly house overseas, but Chinese New year is interfering with that plan at the moment.
     
  6. earnmyturns

    earnmyturns Smartest friend

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    Don't blame them, it's not the time to take risks.

    I'll wait, delays in audio gear production are the least of our worries, and AES is doing well anyway.
     
  7. HumanFly

    HumanFly Acquaintance

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    I just had a peak at the coming soon section on the pi2design website....now that looks promising! :)
     
  8. Dr J

    Dr J Friend

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    Very interested in a compute module based variant. I wonder how the power supply is planned to be done. Personally would like to use a high quality external linear power supply to tame unnecessary power supply quality nervosa.
     
  9. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    The CM4AES takes 5V directly in. The compute module is powered from this trail. The clock generators and the WM8804 are powered from a very low noise LT3042 LDO. We will supply an external 5V Meanwell supply as an option. But you will be free to use your own linear supply.

    There is also a switching supply to generate 3.3V for the SSD.
     
  10. gixxerwimp

    gixxerwimp Professional tricycle rider

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    I noticed a Mean Well retail outlet across the street from my office complex while driving home today. Will have to check it out!

    20210308_222527.jpg
     
  11. Whistle

    Whistle New

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    I am from Europe and my question is if it is possible to get the PI2AES already built together with RPi with an order on the dedicated website? @Michael Kelly
     
  12. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    It is not something we offer. Perhaps someone on the forum would help you?

    We will have a new product called the CM4AES that will be re-installed in it's own enclosure. Check our web site at the end of this month for the official introduction with documentation.
     
  13. Walderstorn

    Walderstorn Friend

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    I have no problem helping but, as @Michael Kelly advised, it's best to wait a few more weeks and you can have the whole-in-one directly from him, with less chances of problems and without you having to pay also for EU postage.
     
  14. Whistle

    Whistle New

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    Ok, than I will wait.......
     
  15. HumanFly

    HumanFly Acquaintance

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    @Michael Kelly - Did you have to make changes to the signal path to get it to run on 5v instead of the 24v for the PiAES?
    Or is the design identical when it comes to the processing of the audiosignal? Or am I way ahead of schedule with these questions?
     
  16. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    The PI2AES has a wide input 5V switching regulator that is fed from the 24V input. The CM4AES accepts 5V directly. From there both designs use the low noise LDO from Analog Devices, the LT3042, to power the NDK clocks and the WM8804. The output circuitry is the same on both.

    The CM4AES does have an additional 5V to 3.3V switcher to power the NVMe sockets.

    A low noise external linear would have a bigger effect on overall system noise than it would on the PI2AES. Which may prompt us to design and offer one. I would love to hear which ones are considered legit.
     
  17. HumanFly

    HumanFly Acquaintance

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    I have a SBooster 5-6v which I consider good enough, not sure if I could upgrade to something even better and still percieve a difference. Devices themselves are getting better all the time, I got my SBooster to feed one of the early Allo hats and it made a big difference, with the 502 it`s less noticable but I think I still hear it.

    The Allo Shanti is quite good too, when you consider it`s price and the fact it has two outputs it`s really good, but you can`t set voltage and it`s big and FUGLY! (Although it does light up the room in a nice warm orange that goes well with the 502 RGB lightshow and Yggdrasil`s lasers :)
     
  18. Dr J

    Dr J Friend

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    I went with Jay's audio based on atomicbob's measurements. Other well-known/advertised high-end power supplies do not seem to provide much in terms of measurement results or specs.

    Allo's Shanti is an exception as there are measurementsif I recall corretly.

    A thought: How about offering a decent, not-uber-expensive power supply plus @atomicbob 's noise nuke which works wonders on all kinds of power supplies? There is probably a demand for this from DIY-challenged like me, even those that do not think of buying the streamer...

    https://www.superbestaudiofriends.o...ise-nuke-for-hp-amps-with-external-smps.5142/

    Edit: link
     
    Last edited: Mar 14, 2021
  19. LogansRunRx

    LogansRunRx New

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    An eternity ago (c. 12-14 months)... there was talk of a AKM-dac add-on for the 16-pin I2S output of the Pi2AES. i'm in a transitional phase for my system (aka, eating ramen and saving for a new DAC) and the all-in-a-box option is appealing right now. have the Pi4, 7" Pi touchscreen, Pi2AES and case on the way to me.
    did the AKM board happen - or did it go the way of the AKM factory? :(
    Curious...
     
  20. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    We were still playing around with the circuit to get the best results when the akm factory fire happened. Not sure we're going to resurrect it even though we can get the parts in modas quantities, if we're willing to pay through the nose for them!

    Right now we're focused on shipping PI2AES boards as soon as they come in and getting Mercury ready for testing as soon as the prototypes for that show up. Seems like everything has been delayed these last couple of weeks. Not sure if it's just our luck or something going on in general.
     

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