Tomson

I am using Raspberry Pi 3 and encountered similar problem when I tried to play HiRes content. Perhaps I can share a little bit of my experience for your reference. My setup is a Raspberry Pi 3 with Chord Mojo DAC. I installed MoodeAudio on the Pi3 as the UPnP/OpenHome renderer. Music files are stored on a QNAP NAS with Minimserver installed. The setup worked fine for normal 16 bit / 44.1KHz files encoded in Apple Lossless format. Sound Quality is good but if I play any HiRes content, occasionally cut-outs may happen. DSD playback is worse and seemed impossible. After weeks of trial and error, I concluded that this was a fundamental USB hardware/driver issues. The Pi3 just cannot catch up with heavy USB traffic as most of the data transfer are going through the same USB bus. Problem occurs even before the USB bus were not saturated. I cannot find a fix that completely eliminate the problem, but there were a few tweaks that I found useful after hours of google searches and tries. 1. Change the CPU governor from 'ondemand' mode to 'performance' mode. This keeps the the CPU running at full speed at all times. This setting seemed to bring most significant improvement in my setup. HiRes ALAC files at 24bit/96KHz content is playable after this tweak. 2. Install Advanced kernel to run Music Player Daemon (MPD) in FIFO realtime mode. This makes the music playback services operate in the highest priority. This tweak is not as significant as the previous one, you may consider doing it if you want to push the Raspberry Pi to its limit. 3. Change from Wifi to Ethernet. I think this depends on your situation. In my area, there are almost 20 wireless access points around that make the 2.4Ghz band congested. After switched back to wired connection and turned off the onboard BT/Wifi, I experienced less frequent cut-outs (this was tried and tested before the first 2 tweaks, so I kept this setting since then.) After the above tweaks, I have no problem in playing HiRes files including DSD64 SACD rips... However the Raspberry platform is really limited that It cannot go further to DSD128 or DSD256. There are some other tweaks that I found online, such as changing of memory clock and USB settings in the config.txt, but the improvements were limited in my case... some settings even brought negative results. If you are using your Raspberry Pi for UPnP streaming, I'll suggest you to give MoodeAudio a try. It is similar to Volumio or RuneAudio, but comes with more options to customise your Raspberry Pi. All three tweaks I mentioned above can be set directly via the GUI. You may try if those settings would help in your case. I have neither Raspberry Pi 2 nor I2C sound card, I can't be sure if the above tweaks work or not... but these are all free so it may worth to try. Hope it helps. Sent from my iPhone using Computer Audiophile