Problem with Raspberry Pi NAS Server / ALIX - Voyage MPD / 24bit 192khz files

[Natural Sound]

As some of you know I've been using a Raspberry Pi micro computer with an external 2 terrabyte drive as a NAS/NFS server. I was using Arch Linux as the OS due to its low resource footprint. On the client side I'm running an ALIX computer with Voyage MPD. Out of the ALIX via USB into a Micromega MyDac. Then into input #2 on my Extended FPIII.

This setup worked great for many years. It played everything I had in my library. But my library never included anything encoded above 24bit 96khz. Then I purchased a couple of albums encoded at 24bit 192khz. These high sample rate files would skip a lot. I tried tweaking the MPD conf file but nothing I did would stop the skipping. Then it dawned on me, I was running a very old version of Voyage MPD. Thinking that might have something to do with it I downloaded the latest release and installed on a fresh CF card. I still had the same problem.

I started thinking that the DAC might be the problem. But when I hooked it up to my desktop computer and played the high sample rate files there was no skipping.

This left two possibilities. 1) My network wasn’t fast enough or 2) There was something wrong with the Raspberry Pi.

Turned out it was a limitation on the Raspberry Pi. I knew that the Pi had an odd USB control implementation that affected its performance with certain USB DAC's. Turns out that the Ethernet connector uses the same controller as the USB. Since my HD is USB and its streaming the files over the Ethernet I figured I was maxing out the capacity of the controller.

Solution - I Installed NFS on a Mini-ITX computer I had laying around. This board has a Gigabit network controller separate from the USB 2.0 controller and is capable of transferring network data at much higher speeds. Now my system is playing 24bit 192khz files in all their glory.

[John EH]

Shame to have to gravitate away from the RPi as it is such a wonderful platform however if it isn't getting it done then it's time to move on.

I just built an RPi B+ system with Arch and am running two DAC's off of it.  One DAC is hogged by squeezelite and streaming through LogitechMediaServer using Spotify, Pandora, and TuneIn Radio.

DAC number 2 is hogged by shairport which is the Apple Airplay emulator.  I don't do anything but stream on the bedroom system in fact even though i have a ripped FLAC library I generally just stream my music anyway unless I just happen to own what I'm listening to.  Nothing I have is higher rez than 24/96 but sure glad I saw this post unless I make the next move.

ITX may have it all over ARM when it comes to this kind of application and I agree sharing USB and ethernet, while it technically works isn't tailor made for what you were doing.  You did the right thing.  Great write up.  Thanks.

[STURMJ]

I played around with the Raspberry Pi this summer also.  I have a huge library and found that with the limited memory capabilities, and the combined lan-usb controller it just could not do what I wanted.  Since then, I have gone to a Intell NUC running JRiver. This combo really got me going towards pure digital.  So much that I built a file server (M-ATX-AMD) with 12TB of disc space running Freenas and ripped all my DVDs and BluRays as well.

The Pi is a brilliant device, and a cheap way to get something done (but only one thing at a time).  And I learned a lot trying to get it to work. I knew nothing about Lunix, so the learning curve was steep for me (but I was a MS-DOS wizard back in the day).  But in the end, I learned that managing a large file structure and decoding Flacs was more the the Pi could handle.

[John EH]

I played around with the Raspberry Pi this summer also.  I have a huge library and found that with the limited memory capabilities, and the combined lan-usb controller it just could not do what I wanted.  Since then, I have gone to a Intell NUC running JRiver. This combo really got me going towards pure digital.  So much that I built a file server (M-ATX-AMD) with 12TB of disc space running Freenas and ripped all my DVDs and BluRays as well.

The Pi is a brilliant device, and a cheap way to get something done (but only one thing at a time).  And I learned a lot trying to get it to work. I knew nothing about Lunix, so the learning curve was steep for me (but I was a MS-DOS wizard back in the day).  But in the end, I learned that managing a large file structure and decoding Flacs was more the the Pi could handle.

I have tons of RPi's.  Use one for a Wifi hotpot on travel, one for a shairport server, one for a LogitechMediaServer and Squeezelite player, another in my suitcase with my mobile printer as a CUPS print server and LMS Squeezelite and web server.  When I go on travel I repeat the wifi on my own router and then set up a printer and web server.  My coworker can print and view files / photos on my server.

I also run OwnCloud 7 on a Pi here at home with a 1TB drive attached.  All the files I need on the road go on the Owncloud Pi.  Keeps things minimal on the road.

Another pi does a digital sign at my gf's business.  And I have several pi's laying around doing nothing, just gave one away to some kid.

I can use the heck out of a Pi but I'm with you in that I wouldn't want to rip FLAC's with it.

My favorite set up is upstairs on my Bottlehead Paramour / Foreplay / SEXy Speaker set up.  I have an R Pi B+ set up with 2 DAC's.  One DAC is ODAC with LogitechMediaServer and the other DAC is HiFIMeDIY which is hooked to shairport.   I can get iTunes, Spotify, Pandora, etc, etc, etc on one R Pi and it sounds very nice as well.

[John EH]

I kind of cracked the code on this. It was my DAC.  I installed an IQAudio DAC+ on my Pi B+ and played 192/24 stuff.  A tad choppy.

Adding

buffer_before_play "100%"

and overlocking the Pi in

/boot/config.txt to 900 MHz by uncommenting out that section.

Perfect playback over the network with all my 192/24 gear.  IQAudio DAC sounds great as well.  I cannot for the life of me get this to work on HiFiBerry DAC's.

[Natural Sound]

I kind of cracked the code on this. It was my DAC.  I installed an IQAudio DAC+ on my Pi B+ and played 192/24 stuff.  A tad choppy.

Adding

buffer_before_play "100%"

and overlocking the Pi in

/boot/config.txt to 900 MHz by uncommenting out that section.

Perfect playback over the network with all my 192/24 gear.  IQAudio DAC sounds great as well.  I cannot for the life of me get this to work on HiFiBerry DAC's.

Cool, I'm glad you figured it out! I'm not a big fan of overclocking anymore but.... If you add the optional heat sinks I guess you'd be OK.

Quick question. Is this success with network area storage or a USB drive connected to the Pi?

A quick update on my NAS server. I needed the MiniITX computer for another project. I've been wanting to try an HP thin client as a file server for a while now. I picked up a NOS T5730W on e-bay for $50 shipped. This is a discontinued model that was manufactured in 2009 but it was new. I received it still wrapped and sealed. It has an AMD Sempron 2100+, 1 GB DDR2, 2 GB Flash HDD. The flash hard drive has Windows XP Embedded on it. Being a Linux guy that had to go. I knew I wanted to use a version of Debian since that is what I'm most experienced with. I also knew that it had to be relatively small due to the 2 GB flash hard drive limitation. Then it dawned on me. I'm already using "Voyage Linux MPD" on my ALIX computer in the listening room. Voyage also has a non-MPD image and its based on Debian. So I burned a live install boot disc and was on my way. The installation was a breeze. Voyage Linux takes less than 256 Mb to install so it fit on the 2GB flash hard drive module with tons of room to spare. The OS is really stripped down. There wasn't even an editor installed. I installed "Nano" as my editor of choice. I edited my FSTAB file to mount my 2 TB external USB drive on boot-up. Then I installed and configured NFS and was on my way. The whole setup took less than 15 minutes.  

[John EH]

These are network shares I'm playing. I previously had an Airport Express upstairs to feed the same Pi using Rune audio an ethernet connection.  Rune Audio sucks at WiFi for some reason.

So I'm playing my Pi with Arch music at 192/24 flawlessly on Wi-Fi and then I think I don't need the Airport Express extender anymore.  I unplug it and wifi drops.  Made sense as that Pi latched on to the nearby signal.  So I rebooted it and it grabbed the same network downstairs and then 192/24 playback had the occasional hiccup.

Plugged the extender back in and now it's all perfect. So I should add you need a good nearby, strong wifi connection or ethernet.  But with that good wifi signal my playback is flawless.

I should also add that Logitechmediaserver and Squeezelite on the same Pi plays back, at the proper resolution, anything you throw at it without choking ever, even on crappy wifi.  I'm starting to think MPD ain't all it's cut out to be.