Paul I had some heat issues with heat on my early Pi 4’s so yes I started to put heat sinks on everything
The whole Flirc case is a CPU heat sink in itself, as the case comes down onto the CPU. It’s a good case and at least one of mine (running DietPi) has been up for over a hundred days as well as driving one of my headphone DACS (and doing DNS duties as well).
The other is currently running VitOS again, though I am sure I will test the latest PopieeeXL again soon and then back to VitOS again.
Good that the LPS made such a difference for your listening experience
Have a good Christmas and enjoy the new setup.
I’m going to demonstrate building a Roon endpoint from a Raspberry Pi 4 using VitOS tomorrow. I’ll be taking questions live, so feel free to join if you happen to be around at 1:00 pm PST on Tuesday, December 29th. I hope to have the stream up a few minutes early. Hope to see some of you there.
I’ve been using VitOS for the last week on my RPI4 4gb model. Easy to install, and works well.
But I do want to call out an odd behavior that did NOT occur on Ropieeexl: When switching between songs of different bitdepths/frequency rates, VitOS truncates the first few samples while the DAC is still switching. This results in the first few milliseconds of a song being cut.
Ropieeexl has some sort of “wait” logic for the DAC to switch frequencies, and THEN begin playing. I never noticed the truncation when switching. But VITOS does it every time.
I prefer to play the songs bitperfect to the DAC, and let the DAC perform the switching instead of upsampling everything to the same frequency.
I’ve not noticed this, but @Yethal’s suggestion should work. If you were not able to attend my live stream, have a look at the playback where I describe how I attempted to objectively measure network performance between VitOS, RoPieee, and DietPi.
Here are some round-trip plots and statistics from Wireshark. I collected these while playing Blue in Green from Miles Davis’ Kind of Blue. This is a 24-bit, 192 kHz download from HDtracks.
Again, I don’t understand why there would be a correlation between lower endpoint latency and subjective sound quality, but Silent Angel at least does what they claim to do regarding network performance. And, VitOS does sound better to me, for whatever reason.
I still have my pcap traces. I’m 99.9% certain that the lighttpd-angel process is there to respond to the mobile app. All of the code for the app seems to have been written in Bash. Unusual choice, but I guess it works. I’ve not seen anything sinister in there so far.
[root@VitOS ~]# ls -l /srv/sh
total 80
-rw-r--r-- 1 root root 3875 Dec 4 2020 app.sh
-rw-r--r-- 1 root root 1543 Dec 4 2020 app_device.sh
-rw-r--r-- 1 root root 343 Dec 4 2020 app_manage.sh
-rw-r--r-- 1 root root 17513 Dec 4 2020 app_network.sh
-rw-r--r-- 1 root root 2942 Dec 4 2020 app_network_verify.sh
-rw-r--r-- 1 root root 6013 Dec 4 2020 app_roon_bridge.sh
-rw-r--r-- 1 root root 3121 Dec 4 2020 app_storage.sh
-rw-r--r-- 1 root root 15034 Dec 4 2020 app_versions.sh
-rw-r--r-- 1 root root 809 Dec 4 2020 roon_install.sh
-rw-r--r-- 1 root root 76 Oct 3 18:14 roon_install_kill.sh
-rw-r--r-- 1 root root 2083 Dec 4 2020 saos_app_install.sh
-rw-r--r-- 1 root root 2467 Dec 4 2020 saos_update.sh
Only had a quick play with VitOS but did notice that both the USB and Ethernet interrupts are running at a very high priority (-51)…so I would image this would help reduce network latency but there may be other things also (plus it’s real time kernel). Would be interested to know more about any tuning they have done but agree can’t really correlate how reduced network latency would improve SQ
That’s not very good…Silent Angel Audio should not be distributing Roon Labs software from their website without permission as this would be a violation of Roon Labs copyright.
Cc: @Chorus_Chuang and @danny - hoping you guys can work this out in an approved way offline.
In my video, I incorrectly assumed that the button in the app to install Roon Bridge triggered VitOS to pull the software down from download.roonlabs.com. This is not the case…at least as of the December 7th, 2020 VitOS image. :-\
David do I remember correctly that VitOS only supports USB output and not Hat boards?
I just got a new Pi and a Digi+ Pro and (plain) Ropieee is installing now, though I might want to try this wireless as I plan on moving around testing it with different devices and maybe running it off battery
David I think that is why they have the App as that is pretty much its job.
Download and install RoonBridge and reading another thread Roon said they could not distribute Roon code as part of a distribution, so I assume this is how they got around it.
