Sound quality gap between Rune/Raspberry Pi2 and Arch laptop

[delleceste]

Hello everybody.
After using a computer laptop running archlinux + realtime kernel + alsa + mpd to achieve bit perfect data stream over usb to my bryston DAC, I decided to give a try to RuneAudio on a new Raspberry Pi 2 model B (1GB ram, 900MHz quad core).

After the installation I configured the network and mounted a usb storage containing some sample hi res files, in order to watch for any sound quality differences between the sound obtained by the Rune / Raspberry vs my arch linux laptop.

I tried to tweak all the configuration options in the MPD section of the Rune, and also copied over the same mpd.conf as the one installed on the arch laptop.
I also tried to switch between kernel optimization profiles in the system menu of Rune.
No matter how I try, the sound obtained by the laptop is wider, more detailed, present and vivid.

The CPU load on the Rune is not so high though, even when playing 24/192 files.

Have you got some other advice, or any hint for the reason why the difference is so audible?

The raspberry is powered by a 2.4A power supply and has a wi fi dongle (TP-LINK) connected to one of the usb ports.

Thanks again for your help!

Giacomo, Italy

[Orion]

Hi Giacomo,
pleased to meet you on our forum. Your post is very interesting to me, because I work on system optimizations and I try to reach the best performance as possible. Are you interested to work together with us on the various aspects of the system configuration and make some comparisons? I think that the main reason of the audibile performance gain is the x86 RT kernel, but could be also matter other aspects of the system configuration. I'm also interested in your x86 configuration since I have an x86 build of RuneAudio almost ready to release.

Feel free to PM me if you want to collaborate.

Ciao.
Simone.

[Aquarius]

I'm interrested in this as well.
A lot of friends have NUCs with Daphile (a Squeezebox distrib) installed and it's very good. I'd like to know more about RT kernel optimisations and maybe test Rune on my Bay Trail HTPC. (very low power, last gen Atom CPU on a passive system).

Note:
Those crazy HiFi extremists use very expensive power supplies with their NUCs, it it something you tried on your laptop ?

Cheers!

[jazzaj]

For my part, I'm coming to Rune audio (+RPI2B) after trying Daphile (RT kernel) on a eeepc 1101HA (supplied by battery). No doubt that Runeaudio is much better (with a linear regulated PSU @ €69).

[Zephram]

If you're serious about sound, keep yor hands off the RPi. It has too many critical design issues to sound really good. The most problematic one is the poor USB implementation, which is still present on the new RPi 2B.

[jazzaj]

@Zephram : looking at your profile, I suppose that you have a cubitruck and you pretend that cubitruck has a better sound (on USB output) than the RPI2B ?

I read something like that (the poor USB implementation on RPI(2)) on a volumio forum, but I must admit that I'm pleased with the RPI2B/Linear and regulated PSU combo and my dac.

For the moment, I own an Audio-gd NFB15 (WM8741) that can only play PCM files (32bit / 384K Asynchronous Transfer USB-32 Chip). But in few days, I will receive an Audio-gd NFB1 (ES9018) with an Amanero combo 384 upgrade that can play PCM and DSD, DXD files + i2s for both PCM (via USB output on amanero) and DSD (ES9018) files.

I will be very pleased to have the opinion of Runeaudio's developers about that question of 'serious sound' for serious DAC. I suppose they listen runeaudio on RPI, RPI2B, CUBITRUCK and others, with quality DACs and they can say honestly if there is a better than other solution to listen music on an audiophile way.

[ACX]

[Tinitus]

Hi,

I think Andrea is right for USB Audio there are better solutions than Pi (my Odroid C1 for instance which doesn't have I2S). So no need to spend more than for a Pi2 but if you don't have problems with using the Pi via USB no need to bother. Not sure if X86 architecture is inheherently better than ARM over at Aktives hoeren forum (in German) there is a guy (frankl) who improved sound quality by swapping an Alix board against an Ordroid XU, he also claims that you do not need a RT kernel for excellent Audio performance. Even if this was the case why not run a RT kernel on a device like the C1?
Please do not abandon the ARM family. I think the low power consumption is a big advantage. I use my C1 with an Audio GD Master 7 via USB and it sounds very good. Only thing I am missing is a switch the polarity of the Audio signal, because some recordings have reversed polarity.

Keep up the good work

Uwe

[jazzaj]

thanks for your answers. the fact is that i'm pleased with my rpi2. i will wait for my new i2s dac and, depending on the results, i will go to a cubitruck or something else, but still using runeaudio.

Envoyé de mon MI 3W en utilisant Tapatalk

[Discovery]

For what it's worth I have a RPI2 with a HifiBerry Digi+ board. This allows me to use an I2S optical output to my external DAC and I can also have the DAC connected simultaneously via USB. This allows me to switch mid-song between each input on the DAC. I hear no discernible difference between USB and optical - both sound great.