Dummies Guide to Pi2AES! Throw away your PC or laptop.

Discussion in 'Digital: DACs, USB converters, decrapifiers' started by purr1n, Jan 29, 2020.

  1. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    Emphasis on the word “slightly“.

    Michael
     
  2. Baten

    Baten Friend

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    Well that transformer is just to convert from 110 to 75ohm right. Which is a little silly since there is already a 75ohm BNC output :) @tommytakis I fear you bought something unuseful, can't think of a use case where the higher XLR/AES output voltage will serve a purpose, except for incredibly high cable runs, maybe.
     
  3. famish99

    famish99 Friend

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    The word you're looking for here is "useless".

    The only reason to run the balun, like Marv did in the case of the Lynx, is when you have a device that only outputs AES and you'd like to get a single ended connection out of it. If it has a BNC connector already just use it man.
     
    Last edited: Mar 31, 2020
  4. tommytakis

    tommytakis MOT: E.T.A Headphones

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    Thx everyone, just went ahead and cancelled my order :)
     
  5. M3NTAL

    M3NTAL Friend

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    I don't want to read between the lines and assume anything, but are people saying the BNC -> BNC connection is better than an AES -> AES connection with the Pi2AES ? I believe the AES connection on my SFD-1 is better than the coax or optical st inputs.
     
  6. MisterRogers

    MisterRogers Ethernet Nervosa

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    No. At least not in my experience. Assuming decent cabling with proper impedance for each, they're both good. At least that's been my experience.
     
  7. fastfwd

    fastfwd Friend

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    In my earlier post I said that the AES output had slightly higher jitter than the BNC. As @Michael Kelly later indicated, I should perhaps have said "very slightly"; the difference he reported earlier was fractions of a picosecond.

    But regardless, you can't draw a conclusion from that single fact. A connection is FROM one device TO another, THROUGH a cable, IN an environment, and signal quality depends on all the characteristics of all of those factors.
     
  8. Michael Kelly

    Michael Kelly MOT: Pi 2 Design

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    Other folks have mentioned this along the way, but I think it bears repeating. There is no one best link. It depends upon the capability of your DAC to get the best sound out of any of its interfaces. So if you’re DAC has a BNC input you use our BNC output. If it only has optical, use optical, so on and so forth. Then it is up to you to decide which of those combinations with your DAC sounds the best.

    Our goal with the PI2AES was to provide the user multiple, simultaneous outputs with as close to equivalent performance as possible. BNC, RCA or XLR are virtually the same. Optical, is however, a bit of an outlier in that it usually has higher jitter then the other interfaces. This is just due to the nature of optical transmitters and receivers.

    So, use the PI2AES to connect to your DAC using its “best” input. Best being up to you to figure out! Fun times, no?

    Cheers,
    Michael
     
  9. dubharmonic

    dubharmonic Friend

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    Is the consensus that the Yggdrasil responds best to AES?
     
  10. Cakecake

    Cakecake Guest

    can someone help how to setup qobuz with moode? I have bubbleUPnP installed on PC and see moode upnp but dunno what to do after. I want to control qobuz with my phone
     
  11. YMO

    YMO Chief Fun Officer

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    PM me with your # and we can do it step by step.
     
  12. earnmyturns

    earnmyturns Smartest friend

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    My experience is that it depends on the sources. I went through the following sequence ("<" means worse than): Auralic Aries Femto AES < Allo USBridge + Sbooster LPS Unison USB < Pi2AES AES.
     
  13. Dr J

    Dr J Friend

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    For those that are concerned about Pi4+Pi2AES heating up:

    I also noticed that running Volumio with Pi4 and Pi2AES in the Pi2AES case caused the Pi4 to run very hot. As in burn-my-fingertips-hot when touching the USB or ethernet ports.

    Did a bit of reading and experimentation on the subject. Please note that I am not an expert on the Pi and the last time I did anything significant with Unix/Linux was decades ago, so feel free to correct/augment.

    TL;DR:
    - Heating up is a general Pi4 thing, not a Pi2AES thing. Closed cases are not recommended for Pi4 for more intensive computation. But you cannot fry the Pi4 as it throttles down the CPU if it heats up too much.
    - Moode runs clearly cooler than Volumio
    - Setting the governor in Moode to "on demand" and switching off all devices not used in the Moode config/system settings brings the temperature down nicely.
    - You can further underclock the Pi4 etc. to tweak things to possible audio perfection but they do not impact the temperature in any significant way.

    Long version:

    My setup is to stream from Tidal or files from BubbleUpnp running on Android to Pi4+Pi2AES acting as UPNP server and using the AES output to the DAC. No other connections set or usage enabled.

    1. The Pi4 heating up seems to be a well-known challenge for anything requiring a bit more computation. It is not related to the Pi2AES but a general Pi4 thing. Latest firmware from Sep 10th 2019 seems to fix a lot of this, but Pi4 still runs clearly hotter than Pi3.

    2. It seems that the Pi4 running at 80 degrees Celsius is still within the spec and should not even cause significant problems with longevity of the components. The CPU throttles down if its temperature exceeds 85 degrees.

    So you won't fry the Pi4, but I still wanted to have a solution with a bit more sane temperature esp. with the Pi2AES getting its share of the heat and possible impact on the component life-time.

    3. The recommendation seems to be not to use a closed case with Pi4 for anything more computation intensive. Open/ventilated cases, positioning the Pi4 vertically for better ventilation without using a case, heatsink cases and cases with fans seem to be recommended solutions.

    I wanted to use the standard PI2AES case as it fastens the digital connectors whose connection to the Pi2AES board would otherwise be subject to more wear and tear. I also wanted to avoid fans that might possibly pollute the signals. So I went looking for a solution with the standard case.

    4. I first drilled a big bunch of holes to the Pi2AES case and put the case with the GPIO-side down (power socket up, i.e. the vertical orientation trick).

    Running Volumio the Pi reported the CPU temperature at 67-68 degrees C. The Volumio seems to set the "performance" setting of the CPU governor, i.e. the ARM cores are running constantly at 1500MHz and GPU and core at 500MHz.

    The key is to ventilate the space under the Pi4 and between the Pi4 and the PI2AES. That is where the heat gets trapped in the closed case.

    I did not think to measure the temp without the ventilation holes, but it is higher than with the ventilation holes because of Physics.

    5. I then changed the PI governor to "battery saving" (via SSH and command line). The ARM cores then run at 600Mhz and GPU/core at 250Mhz. This brought the temperature to 63-64 degrees C with volumio.

    6. Next I tried Moode with the governor at "Performance setting" and shutting down every device but WiFi (from the Moode web UI / config /system settings). The CPU then runs with the same speed as in 4. The temperature was 57-58 degrees.

    7. Changing the governor in Moode to "on demand" brought the temperature down to 53-54 degrees C. The CPU runs with similar speed as in 5. when no call for more computation.

    8. On the general vague idea from the interweb that less computation, less power usage, and avoiding changing of the core speeds constantly (as the "on demand" does) might be a better thing for an audio streamer, I then
    - underclocked (via the config.txt) the arm to 300MHz, core to 100Mhz and gpu to 100Mhz (as no need for GPU)
    - set the governor to performance (constant underclocked rates) in volumio
    - shut down the Wifi and used ethernet instead, and
    - finally turned off all the Pi4 leds as they annoyed me (via the config.txt)

    This brought the temperature down to 51-52 degrees C. The web UI and streaming from BubbleUPNP seemed maybe a bit more sluggish occasionally, esp. when starting playback or putting files into the queu.

    9. I further explored forcing the ethernet from gigabit to 100mbps and other tweaks, but they mostly caused instability and no reduction in the temperature.

    So, to have decent responsiveness and decent temperature, I ended up with this current setup:
    - running moode
    - underclocked (via the config.txt) the arm to 600MHz, core to 200Mhz and gpu to 100Mhz (as no need for GPU)
    - set the governor to "performance" (constant underclocked rates) in volumio
    - shut down the Wifi and all devices in volumio, use ethernet, and
    - turned off all the Pi4 leds (via the config.txt)

    Moode also seemed more reliable in general in my setup. YMMV.

    I think something like arm at 450Mhz and core at 150Mhz might also have a good enough responsiveness if someone wanted to optimize away the last degree or two.
     
  14. rlow

    rlow A happy woofer

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    Thanks for all the great info man. So is the real answer here to get a Pi3 to avoid all this? I was thinking of swapping my Pi3 board for a Pi4, for potentially better Wi-Fi, but not sure now. I do use Ropieee though, not Volumio or Moode, and it barely gets warm.

    BTW, this is my favourite part of your post: :D
     
  15. Dr J

    Dr J Friend

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    That was my first take.

    However it seems that in the Pi4 the lan, wlan, usb are better separated from each other than in the Pi3, so in theory it might be the Pi4 might be a bit less noisy. But only speculating, did not come across or even specifically look for anything concrete on this.

    I have also a Pi3 (with Digione) with the same configuration running Moode, and it runs noticeably cooler than the Pi4. Just based on touching the case around the ventilation holes. Did not measure it. Might be also the on-demand is set on the Pi3.
     
  16. Taverius

    Taverius Smells like sausages

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    Pi3 is fine if you're not:

    -Using USB Heavily, it's kinda shitty on the 3
    -Using WLAN, as it's kinda shitty too and other options are shitty AND on usb
    -Using the Pi as server, as the extra ram on the 4 really helps there

    As for temps:

    1. Volumio seems rather shittily designed. Who the fucks sets fixed clocks except for benchmarking, especially a device that spends the near totality of its life idle, going by how the battery saving governor didn't cause issues.

    2. If you're at like 75c stop worrying. Even with the soc at 85c and throttling I'd expect the caps to be 10-20c below*, up i bet that'll still last forever.

    The only thing that appreciably degrades with temperature is electrolytic caps, the ones used on computers are good for usually 2k hours at 105c, 5k hours on the very high end, and that's at the tail of an exponential curve of temperature reducing lifetime.

    * Especially if you bought the heatsink set, and if you didn't, why do you hate freedom?
     
  17. Dr J

    Dr J Friend

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    A couple of additional comments and experiments. Then I think I derailed the Pi2S thread enough, happy to continue in the other Pi threads if needed. Wondering if the downclocking actually has any measurable impact on noise...

    1. Moode also runs at 67 degrees C with the governor at "performance" and wifi, BT, HDMI on. I think "performance" was the default setting for Moode, so Moode and Volumio are on an equal footing temperature wise. Maybe the thinking is to avoid changes to the processor frequencies as that might cause some extra noise? (If that noise actually has any measurable or audible impact is another story).

    2. The impact of the ventilation seems to be to lower the temp roughly 4 degrees C (taped the holes shut for 30 min to check).

    3. If you use Moode, downclock the Pi4 to 600/200MHz or use the "on demand" governor, and shut dow wifi, BT and HDMI, the extrapolated closed PI2S case temperature without ventilation holes would then stay somewhere in the 57-60 degrees C range. Which would not be a concern for me.

    4. True that even the extrapolated temp of 72-73 degrees C with Volumio, closed case and governor at Volumio default "performance" setting would probably not be harmful to the circuits. At least the Pi4 is rated up to 80 degrees C.
     
  18. GanGreinke

    GanGreinke Friend

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    If you have been using a Pi4 for a while without updating the firmware, there have been some firmware updates that have reduced the temperatures and power usage of the Pi. You can do the updates in Moode by opening up a terminal in the configuration tab.
     
  19. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    I've been playing around with different distros, software, and the like over the last week or so, mostly out of curiosity to see what options exist, what they offer, how well the do or do not work, and so on.

    My usage consists of a mixture of playing files hosted locally on my network somewhere, streaming with Google Play Music, and Roon. However, now that I've consolidated all the random music libraries I had across different devices onto a single NFS share, I can probably just stick with GPM and Roon.

    Anyway, here are some of my findings:

    - Volumio's latest updates seem to make it more stable. Less prone to crashing when bouncing around different music sources, primarily UPnP streaming and NAS. Not perfect, but much, much better than I was dealing with for a while.

    - moOde did NOT like when I tried to mount the NAS hosted by my router (just a small USB disk plugged into the router with maybe 20 or 30 sample tracks). UI stopped responding, OS crashed frequently...just awful. This never gave me problems on Volumio. I quickly moved on to something else. (I have not totally ruled out user error on my end.)

    - Eventually, I gave moOde another shot, but this time I instead moved everything from the NAS to an NFS share on my local Linux "server." This has given me no problems so far.

    - moOde's Google Music integration is poor. It leverages another app that's using old authentication APIs, ones that don't work properly with 2FA. I modified the code myself to use the new API and was able to login successfully. However, it seems I'm still limited to using something like BubbleUPnP to "stream" GPM music to moOde? I was hoping for some web UI integration...

    - moOde's UI I don't find quite as intuitive or nice looking as Volumio's. Doesn't matter too much. It's functional. Neither are super great anyway.

    - Mopidy is pretty interesting, though not a distro in and of itself. You have to install and configure it on an existing Linux installation. There is a very minor learning curve to its setup and configuration, but I liked its customizability, both in terms of general settings and plugins.

    - Mopidy's GPM plugin used current APIs, so authenticating was no problem. And the two UIs I tried would both recognize your GPM library one authenticated. That I could finally get away from BubbleUPnP was a relief! Unfortunately, I'd hoped I'd be able to browse and search for music that I hadn't purposely added to my GPM library in the past, but no luck there.

    - Mopidy did require me modifying a GStreamer file so that it would successfully play tracks for more than 2-3minutes before dropping them (at least, when streaming from GPM).

    - DietPi as a basic distro is quite handy. It has a lot of nice, built-in management tools (CLI based) to help you configure the OS and install common software you'd like. It more or less manages the software itself afterwards. A fresh build has very few processes running and is of a small install size. You can, of course, configure and install as you like without their provided tools. Good option if you want a base Linux build on which to add your own software of choice.

    - Snakeoil OS turned out to be a bit of a bust. Maybe the latest update broke things, and I came to the part at the wrong time. The web UI is pretty solid, though basic. In theory, one should be able to set it all up without ever hitting the CLI. However, it seems the MPD web clients were all misconfigured, i.e. listening on a different port than what the web UI linked to. And I could never get wireless working on the RPi, for some reason, with this OS. Quite odd.

    I think that more or less covers things so far...

    If anyone knows of a solution that will allow me to browse Google Play Music in the same way I could from my desktop and browser, avoiding UPnP or only being able to select music I've specifically added to my library, I'm all ears!
     
  20. Friday

    Friday Friend

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    Doesn't address your main question, but I find the M.A.L.P. Android app for mpd to be easier to use on phone at least.
     

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