Have been made aware of this blog that details how to build a cheap and silent USB Linux music server. Looks very interesting and something others here might get some tips from.

Cheers

wolster

Interesting........but I'm fairly sure that the new version of Ubuntu Linux has network/server capabilities which means (to the best of my ignorance) you could use the computer to control the NAS to feed the DAC to listen to the music........maybe.

So many solutions to a problem I never knew existed......

That's pretty damn cool however if I was going to have a music server I would use it to stream my music to work or whenever I'm away from home but without unlimited bandwidth like north america I have given up on the idea.

Have been made aware of this blog that details how to build a cheap and silent USB Linux music server. Looks very interesting and something others here might get some tips from.

Cheers

wolster

Long time lurker here ... time for a post i think!

I'm working on a similar project (concept) at the moment - need some spare funds to buy the gear though!

The solution linked is good I'm sure! But I'm wanting to experiment a bit and see if something better is possible.

***Please don't use the below as a springboard for the jitter debate. I am just trying to say that theoretically this should minimise the theoretical issue, not whether or not it can be heard. The concept is just as much to satisfy my own curiosity as anything else.***

I want to set up a similar board as a MPD server for flac playback. However I don't think usb DAC is the best output option. USB audio is traditionally limited to 16/44.1 (a few exceptions to this rule but in general, it holds true) and also traditionally has a number of jitter issues. I am planning to use I2S output to a DAC (most likely at this stage http://www.twistedpearaudio.com/digital/buffalo.aspx).

The reasoning behind this is that I2S from MPD to DAC 'should' reduce jitter by removing any spdif stage for signals that typically add most of the digital signal jitter in the signal path. This can be acheived by running the I2S output port on the playback system from the same high (higher?) precision clock in the DAC of your choice.

The setup process should be similar to that of the linked blog except audio output in ALSA would be set up through I2S port rather than usb.

DIYaudio forums have a number of discussions where people have tried the above concept out, no detailed build logs however. I can dig up some links later if people are interested

hi zman,

well done on jumping from lurker to contributor

I have looked into I2S a bit, but couldn't see that it was worth the extra hassle of implementing it (which is considerable if you currently run SPDIF gear), although I do understand it partially eliminates jitter by removing (well, lessening really) the signal-related jitter caused by bandwidth limitation in the digital signal path.

it would still require careful design of the clocking circuitry (not sure which end of the chain that is done) to avoid jitter in the D/A process.

good luck with the project and please share what you learn along the way

Hi everyone

I've built the server listed. I've been having trouble configuring it to a NTFS storage volume but got it to play back from a Ext 3 no problem. Sound quality is significantly better than from a stock media computer running linux/mpd. Which is way better than any other SW system I have used. You have to hear it to believe it. Nothing like an OS running out of flash, no moving parts, 3 watts of electricity and the track 100% buffered to Ram before play. Why Logitech can't do that I do not know.

It's not easy and you need to know your way around linux (ie be comfortable in terminal and working headless via ssh) but awesome once configured. I have pulled it apart and will reload the flash card with the latest version of Voyage to see if I can get it running a little more smoothly. Somewhere I stuffed up the kernel.

Plan is to set up the D Link DNS 323 with RAID 1 TB storage (it is Linux and Ext 3 with NFS natively).

Would love some linux heads to jump in here and give some help.

USB sounds fine but then again there is plenty of information on 16/44.1 for me.

I'm less concerned with theoretical reduction in jitter via USB transfer and more concerned with reduction of jitter at source. That is where the money is IMHO. Of course both would be nice. Eying up the Ayre QB9.

Anyone else going down this path??

Hi everyone

I've built the server listed. I've been having trouble configuring it to a NTFS storage volume but got it to play back from a Ext 3 no problem.

I'm doing this. I am reading my existing NTFS volume on my XP PRO machine. To do this I use CIFS installed on the Alix. A general guide to what is required is here: http://ubuntuforums.org/showthread.php?t=288534 I use Music Player Minion to front end MPD. This client is a Firefox extension. Eventually I'll set up another Alix machine running FreeNAS to host the music files. Tip: try the shortest USB cable you can find to connect your DAC. I bought a 15cm cable from eBay. The unbalanced 5VDC on the cable picks up noise.

Thank you Jeff

Hi,

Interesting design. Currently I am using Ubuntu + MMS with cheap old IBM laptop, + external DAC.

What would be the benefit of this approach?

Hi Gainphile,

I had a look at your blog.

I'm not sure there are obvious advantages over your set up. Some report the low overhead of running mpd with no display and no GUI results in better sonic performance. To my ears the Alix / Voyage Linux / MPD combo sounds superior to Windows XP / foobar2000 playback using a quiet desktop CPU over the same USB -> SPDIF -> DAC set up.

If you've got the file server in another room, you'll never have the hard drive or laptop fan spin up and interrupt your listening session.

It turns your laptop into a big remote control. Or you can get MPD clients for wifi iPods and wifi phones enabling them to be remotes and music browsers.

One benefit for me: my wife can use Music Player Minion client from Firefox to control playback and create and save playlists. A lot easier for her than using Windows remote desktop and foobar. She can also pop up the client easily and pause the music to answer the phone or skip ahead to the next track if I've put on something she's finding obnoxious. My listening area is shared space so this is important for marital harmony.

It also opens up some interesting DIY possibilities. I'm currently using a cheap, linear wall wart power supply to the Alix, but will probably build something nicer. You could even run it from a 12V battery.

A USB DAC could be hard wired to the Alix board. There are potential advantages to not having a long USB cable picking up noise. The USB data signal is balanced, but the 5VDC line is not.

I can understand why someone might have difficulty seeing a good reason for this kind of set up. I found it intriguing and decided to try it.

Hi Jeff,

Thanks for the analysis. In fact the one thing that is disturbing with my setup is the fan noise, and Thinkpads are the quietest around. It is audible in very quiet night, right there competing with the fridge (but I can turn off the fridge!)

How quiet is the ALIX? Are they completely fanless?

I am intrigued at this possibility, which means I can relinquish my laptop for the kids.

How quiet is the ALIX? Are they completely fanless?

Yes. And diskless. They run the OS from CF cards. Music must be located on a file server elsewhere. Or perhaps on a USB drive - I haven't tried the latter.

See here:

http://www.pcengines.ch/alix2d2.htm

I'd investigate hi-res playback capabilities before biting. I'm pretty certain I read of someone using a hi-res DAC with the set up but I'm just doing plain ol' 16/44.1.

I note a local supplier of the ALIX boards and some nifty cases, power suplies etc... http://www.yawarra.com.au/catalogue.php?page=boards

Basic unit for just over $400 in a box with power supply, board, mem card & operating system http://www.yawarra.com.au/catalogue.php?page=boxes

Question? Are Panel PC's with these boards in them such as those from here http://buy.advantech.net.au/configsystems/compare.aspx?partno=PPC-L61T-R70-XE an option here? Albeit a slightly expensive one...

I like Yawarra's cases for the Alix. Unfortunately, their markup on the Alix boards is typical for the Australian market. Far too high.

I got my Alix 2d2 direct from PC Engines for $260 inc delivery. That included a couple of CF cards and an inexpensive case. I had a suitable PSU already.

An extra 10-20% to support local suppliers is cool. An extra 50% is not!

Edited July 6, 200916 yr by Jeff65
Added last para

An extra 10-20% to support local suppliers is cool. An extra 50% is not!

With you on that.....shame really

I bought mine from Netgate in the USA. Even with shipping it was about the same as Jeff paid. I had a 12v li ion battery pack lying around so I just use that.

I can report a significant improvement in SQ (totally subjective, in my system no dbtx no interest in dbtx etc etc ) going from

• XP + asio
  
• Vista/Win7 + Wasapi
  
• Mac & iTunes (on Mac Mini)
  
• Linux (on media centre) + mpd/minion
  
• Alix 2d2 + mpd/minion.
  

Like Jeff I use Minion. My wife likes it as well. I'm eagerly awaiting the release of the CrunchPad http://www.techcrunch.com/2009/06/03/crunchpad-the-launch-prototype/ , which I reckon will be an awesome remote control plus tablet browser.

Incidentally I also tried XX High End with an ESI Juli. Great sound quality but fiddly and not especially convenient (you need Vista wasapi drivers for your spdif transfer in your SC - "Vista compliant" don't cut it- hence the Juli). I thought the ESI juli@ reasonable with ok converters and was useful for spdif out duties. Not a patch on RME IME though. Plus it was pretty flimsy in it's connectors - the break out cables just plugged in and were easily dislodged.

The main issue I had with XX High End was having to shut down all the Vista services and run headless when you wanted to achieve good SQ when Linux natively does it just as well or better. I'm sure it will mature but for me it just isn't there yet. In linux it is dead easy to get 1% cpu load and next to RAM use whereas in Win/Mac it is not.

Others I know report great results with XP & CPlay. Haven't tried it so cannot comment.

The computer you run the platform on makes a big difference. Not all mobo's are the same nor are all HDD/power supplies etc. Lappie's (unless they are Mac's) don't sound that good as sources to me - I don't know why - presumably because they have lots of EMI and are relatively resource hungry. Plus they are noisy beasts.

Hands down linux + mpd + dac sounds the best in my system. I dual boot Win7 (for other duties) and Linux Mint (for music) on my htpc and there is no question that mpd + linux sounds significantly better than Win7 (with all the services shut down ala XX High End) running Foobar & Wasapi USB out.

The Alix is better still. I put that down to a very low o/h/no moving parts = minimal power draw, very little EFI, Ram buffering, Flash OS, a quiet bus port and hence low low jitter at source. It certainly isn't the quality of the on board clock he he:D

Of course that is only testing them all with a twin clock USB Valabs. Which is good but not great.

I'm not for a moment suggesting that this is the only way to achieve great computer audio. I am sure a Mac plus a Weiss Minerva would sound really magical. But then again I am confident the Alix would as well with a really competent dac.

Now onto asynchronous dacs...Ayre are a few months away from sending some QB9's down under. I spoke to the importer and they are apparently quick on the press releases but not so quick sending out. Here is a list of current usb dacs (more or less): http://www.audioreview.com/usbdaccrx.aspx

Might I suggest it can't be that long before everyone else works out how to implement asynch usb. I can't believe Gordon of Wavelenght or dcs are the only audio engineers in the world that can work it out. Which is not to undermine their achievements

Jeff - are you in Sydney? What dac are you using?

Cheerio

Norbett.

Edited July 6, 200916 yr by Norbett
tidying upmy late night post

I have other plans......

c'mon Norbett, don't be a tease now! What's next?

I've nearly saved up enough money for my embeded linux system + dac so looking for ideas!

sorry can't say till I have done it. Which might be a while. Awaiting ffado development of RME drivers: http://www.ffado.org/

But the hint is something like an Alix but with firewire to an RME converter.

Jeff - are you in Sydney? What dac are you using?

I'm in Melbourne.

I'm using a HagUSB feeding SPDIF to an AudioSector DAC.

AudioSector now makes a USB input version of the same NOS DAC which would simplify things, although I'd lose the pulse transformer SPDIF interface which interrupts any ground loop current between the audio system and Alix. The Alix DC supply floats, but I wonder about the ethernet connection to other computers. I've held off updating to the USB version because I've got some DIY ideas I want to try.

On the other hand, if I came across a second hand Wavelength Brick, I'd buy it.

On the other hand, if I came across a second hand Wavelength Brick, I'd buy it.

ha ha wouldn't we all! My friend Nick L in NY uses an async Brick and loves it.

Wavelenght will have a local distributor here soon - the first shipment is on the boat according to Gordon.

Let's hope the rrp pricing will be the USA equivalent + GST+ shipping+ duty (another 20% I suggest). The importer is not one of the usual suspects.

Yes I spoke to the Audiosector fellow - Peter Daniel is it? The USB converts to i2s but doesn't address clock issues at source. I'm sure it is an excellent dac however and I am sorely tempted.

Do you find it melodious?

Thanks

Norrie

I like the Audio Sector DAC. It's very good at the price offered. I also have a HagDAC module that is used in the Hagerman Chime DAC. I prefer the AudioSector, but I have only used the op-amp outputs on the HagDAC. It has raw outputs from the passive I/V that require around 30x gain to get to line level. I'll eventually have a valve stage for it, but I have too many projects.

Hi everyone

I've built the server listed. I've been having trouble configuring it to a NTFS storage volume but got it to play back from a Ext 3 no problem. Sound quality is significantly better than from a stock media computer running linux/mpd. Which is way better than any other SW system I have used. You have to hear it to believe it. Nothing like an OS running out of flash, no moving parts, 3 watts of electricity and the track 100% buffered to Ram before play. Why Logitech can't do that I do not know.

It's not easy and you need to know your way around linux (ie be comfortable in terminal and working headless via ssh) but awesome once configured. I have pulled it apart and will reload the flash card with the latest version of Voyage to see if I can get it running a little more smoothly. Somewhere I stuffed up the kernel.

Plan is to set up the D Link DNS 323 with RAID 1 TB storage (it is Linux and Ext 3 with NFS natively).

Would love some linux heads to jump in here and give some help.

USB sounds fine but then again there is plenty of information on 16/44.1 for me.

I'm less concerned with theoretical reduction in jitter via USB transfer and more concerned with reduction of jitter at source. That is where the money is IMHO. Of course both would be nice. Eying up the Ayre QB9.

Anyone else going down this path??

Hi to all!

I came across this thread via Google; I do a search once in a while to see if anyone is doing anything (audiophile related) interesting with the alix/mpd combo.

If anyone needs help or has any questions I'd be more than happy to help out the best I can.

Sincerely,

Nick L.

Hey Nick

good to see you here! welcome.

I'll drop you an email

Best Norrie!

Still using this single board computer for playback with changes to ancillary equipment. HagUSB is out; Audiophilleo 1 is in. AudioSector DAC is out, Metrum Octave is in. Wall wart power supply to the computer is out, 12V SLA Battery is in.

In a word: wow! The biggest improvement is probably brought about by the Audiophilleo, but it's early days. I haven't done a great deal of comparing.

Is anyone here still using the Alix computers?

Bloody hell. I don't even remember starting this thread.