Pi2 Design Idiot-Proof Ready-To-Go RPi/AES Streamer

Discussion in 'Digital: DACs, USB converters, decrapifiers' started by Michael Kelly, Jan 16, 2021.

  1. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    They’re ~ $10 for the 32gb quantity 1.
     
  2. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    Fun with parts! We added SD Card so we could use the non-eMMC versions of the CM4. Managed to get 60 of the 4GB and have 100 on order from another vendor that claims they will have them in 2 weeks (yes I am aware of the irony ;)). If they deliver then we might launch Mercury with a Kickstarter campaign, if not then just straight sales.

    All these changes have added cost which means that we will likely increase the initial price to $599 and won't be offering much of discount to SBAF. Maybe 10-15%?

    3D render of new PCB:

    upload_2021-8-18_11-21-56.png

    P.S. we also added another LT3042 to power just the WM8804 AES transmitter and an LP2941 to power the output drivers. I want to see if we can bring the PSU noise down and maybe jitter as well.
     
  3. Beefy

    Beefy Friend

    Pyrate
    Joined:
    Apr 10, 2021
    Likes Received:
    1,738
    Trophy Points:
    93
    Location:
    Canada
    OK, I clearly haven't done all my background reading. Is that an M2 SSD slot at the bottom/front?

    [EDIT] Yep, says so right in the first post. Must have missed it!
     
    Last edited: Aug 18, 2021
  4. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    FYI it’s a 2282 size, x1 PCIe.
     
  5. nhqdat

    nhqdat New

    Joined:
    Aug 19, 2021
    Likes Received:
    1
    Trophy Points:
    3
    Location:
    Vietnam
    Hi Michael!
    In prototype posted on May 6 2021, I see the power supply is 5V but with new Prototype (posted on Jul 12 2021) the power supply is 24V.
    Could we use the 12Vdc to power the device? I believe if we use 12Vdc to power CM4AES it will be easy to make or find a high quality 12Vdc LPS than 24Vdc LPS. I've found that common regulator chips (LT1963, LT1764, LT3045) have maximum input voltage value only 20 V.

    prototype posted on May 6 2021
    https://www.superbestaudiofriends.o...go-rpi-aes-streamer.10471/page-10#post-347218

    prototype posted on Jul 12 2021
    https://www.superbestaudiofriends.o...go-rpi-aes-streamer.10471/page-10#post-353388
     
  6. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    Staying with 5V would have required us to supply a low noise 5+ Amp PSU. This is because that 5V would be used directly to provide the 5V for the CM4 and the AES outputs. And to generate the 3.3V @ 3A required by the SSD.

    The idea of 5V in has the only benefit of allowing a linear supply. Theoretically giving you lower noise. Using the 24V to generate the 5V and 3.3V is much more efficient and much, much less costly.

    Finally, we already buy the 24V supplies in bulk.
     
  7. nhqdat

    nhqdat New

    Joined:
    Aug 19, 2021
    Likes Received:
    1
    Trophy Points:
    3
    Location:
    Vietnam
    Thank for your information.
    And there is one more thing: I already had a LPS 12Vdc, could the CM4AES work if I powered CM4AES with 12Vdc?
     
  8. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    Possibly. What I’m trying to do is position this board as the core of a number of different products. All by itself, it is mercury. But I plan to add an analog board and the resulting system will be called Gemini. Finally the addition of a display and possibly a higher end analog board with balanced audio, will become Apollo. For mercury, The highest voltage we create is 5V. But for the others the 24V is necessary both to create the higher analog rails, but also to provide the power without having to run large internal wiring.

    I will have to look to see if I can get the power I will need for these future products with just a 12V rail.

    Please note, this will not change the underlying power circuitry. It is especially not clear that any benefit will accrue from using an external 12V linear.
     
  9. nhqdat

    nhqdat New

    Joined:
    Aug 19, 2021
    Likes Received:
    1
    Trophy Points:
    3
    Location:
    Vietnam
    Thanks Michael!
    It's good to hear that.
     
  10. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    Sending the final (hopefully) Mercury revision today to the PCB shop. It will take about 4 weeks to get them back and build up a couple. We'll get 50 pcb's on the chance we got the SD Card right. Note that we also moved the SD Card to the back, thus widening the board a bit and moved the DC jack to the panel. Box is now 166mm wide instead of 160mm. We also set the PCB back so we could add a future 5" DSI touch display if we decide to. Obviously the box would be taller.

    We have 58 Compute Modules with 4GB Ram and 0 eMMC. We have another 150 ordered and supposedly coming in next week. We received the order acknowledgement, but these days I don't believe until I have parts in my grubby little hands!

    Some 3D captures for the new layout.

    Front:
    mercury_front.PNG

    Back:
    mercury_back.PNG

    Inside:
    mercury_top.PNG
     
  11. alvins

    alvins New

    Joined:
    Sep 19, 2016
    Likes Received:
    1
    Trophy Points:
    3
    Great progress!
     
  12. haywood

    haywood Friend

    Pyrate
    Joined:
    Oct 22, 2015
    Likes Received:
    763
    Trophy Points:
    93
    That was the right move, it’s not meant to be a frequently used port. I still think the folksy font sells your products short but c’est la vie.

    Regarding screens have you ever thought about putting one on the top surface of the case instead of on the front? The ports, etc. would need some adjustment but that would let you have a much bigger area to use for a screen.
     
  13. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:

    If you can make a suggestion for a better font I’m all for it. You’re right it was kind of a goof making boards where no one really pays that much attention to the logo.

    as for the display that is certainly something we’ve actually kicked around. The big issue is usability. I guess we could use some kind of kick out stand that would tip it forward. Because of the power switch we can’t actually set it on its face and even if we could I’m not sure that would work for people.

    in any case (no pun intended) we will definitely have the bigger box with the 5 inch display and analog. That will be called Gemini. We obviously have kicked around a whole bunch of different ways to put these things together, but now that mercury is going out with this revision we are locking things down.
     
  14. haywood

    haywood Friend

    Pyrate
    Joined:
    Oct 22, 2015
    Likes Received:
    763
    Trophy Points:
    93
    If we’re going by the product names then basically anything that you think would look at home on the side of a rocket. There are a ton of free-ish fonts available at fonts.google.com, the bold 700 versions of:

    https://fonts.google.com/specimen/Rajdhani?category=Sans+Serif,Display,Monospace&preview.text=MERCURY&preview.text_type=custom

    https://fonts.google.com/specimen/Barlow?category=Sans+Serif,Display,Monospace&preview.text=MERCURY&preview.text_type=custom

    might be nice. I would add padding to them so they were more like:

    M E R C U R Y

    instead of

    MERCURY

    though.

    Adding streamer to the product name is also kind of redundant, it’s like saying Cadillac car (RIP Cotton Hill).

    You’d definitely want to do a new layout, or at least have some kind of accommodation for ports, etc. if you had a product with the display on the large “top” surface of the box. The advantage would be in being able to use a touch screen full version of the UI, but idk what Volumio looks like on a 5” display, maybe it’s nice.
     
  15. NationOfLaws

    NationOfLaws Friend

    Pyrate
    Joined:
    Nov 10, 2019
    Likes Received:
    874
    Trophy Points:
    93
    Location:
    US
    Just go with Helvetica. Everything looks good in Helvetica.
     
  16. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    I will check them out. Thanks.

    The 5" is actual very usable, even with my old eyeballs and sausage fingers! The 4.3" is OK for tiny hands and the 3.5" would require a stylus and maybe magnifying glasses! Also, the display is mostly eye candy and a bit of a sanity check that things are working. I expect virtually all interaction to be via a phone or computer.
     
  17. dBel84

    dBel84 Friend

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    3,230
    Trophy Points:
    113
    Agreed. I made my own streamer with a touch screen but never used it. When I rebuilt it, I dropped the screen and tucked it away with the other gear. The eye candy was nice to see what was playing but redundant.

    Great progress on the product development!

    .. dB
     
  18. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    Note that you initially put in a screen. Mercury is not gonna have a screen because it’s a more entry-level device, but my other projects based on this will have a screen because, well, it attracts people! And for new users it does offer the benefit of seeing what is going on before you figure out how to get the stupid remote application running!
     
  19. earnmyturns

    earnmyturns Smartest friend

    Pyrate
    Joined:
    Sep 25, 2016
    Likes Received:
    3,218
    Trophy Points:
    113
    Location:
    Palo Alto
    Home Page:
    I currently own a garden-variety Pi2AES as a Roon endpoint, and one with the touchscreen, which originally was part of a standalone system but is for now serving as another Roon endpoint. I'd like to return the screen device to standalone use sometime, and get an additional Roon endpoint. I guess I should get another vanilla Pi2AES, even though Mercury has a nice form factor, as Mercury has more hardware than I need. Am I figuring this correctly?
     
  20. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

    Pyrate
    Joined:
    Apr 22, 2016
    Likes Received:
    4,112
    Trophy Points:
    113
    Location:
    Rhode Island, USA
    Home Page:
    Mercury is essentially pi2aes in a box. There are some slight improvements that we’ve tried to do around the voltage sections to see if we can get the very good jitter specifications even better. It has an option for an SSD drive, but that is just an option and has no impact if you’re not using it.

    It’s really something that we thought we might do with pi2aes a while back, where we would bundle it with the raspberry pi and an image on SD card already assembled in the case.
     

Share This Page