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Oh I see, since you mentioned a nfs server in the bedroom, I assumed that the PC Engine box was located there. So the PC Engine is connected to your amp and utilizing the amp's DAC. And it's grabbing lossless audio from the data center in your bedroom. I was hoping for a fanless silent datacenter, perhaps 1 TB, which would serve my iPod or perhaps feed a DAC in my future amp.
And none of the Logitech products will feed a USB DAC either; your outputs are either S/PDIF or analog out.Cheers
Well, I am going to try and join the club. Total newbie. I ordered the board and enclosure. I have a linear power supply somewhere from parts express that I will use with it. Want to avoid switchers. Have a buddy who likes to tinker with computers and is interested in linux so this will be good project. Wish me luck.
'Tis been a while since I have given an update. With that...I have been happily living with the Alix/MPD combo for almost 2 years now, feeding a Wavelength Audio Version 2 Asynch Brick. The little board has been sitting in my rack doing its job with nary a complaint, that I sometimes forget that I have a cool little custom music server in my midst. After those 2 years, I've noticed the slow proliferation of high resolution music files, and I've been dutifully collecting hi-res "freebies" and sample downloads. I've also found some interesting 96khz material on a website called Internet Archive. With my little Brick being limited to 16bit/44.1khz material, I set out on the Internets for teh research.So, with some hi-res material on hand and plenty of research on possible USB DAC candidates to mate with my trusty Alix, I decided to head off today to my local NYC Ayre dealer who was happy to loan me a QB-9 USB DAC for a home audition. Rushing home after a long and hot day on the EMS truck, I settled down to see just how nice the QB-9 would play with the small embedded board. This being a demo unit on display since this past March, I assumed that it was quite broken in. Would the be any quirks? So far, all is well. 1. Voyage Linux 0.65 recognizes that DAC, and MPD ver. 0.15.8 plays sweet music without any clicks, pops, or hiccups. 2. Switching between 16bit/44.1khz files and 24bit/96khz is seamless and instantaneous with no audible clicks from the speakers or the unit.3. MPD down-samples the few 24/176.4 and 24/192 files I have with ease; the CPU showing 24% load in htop as opposed to 8-9% with native 24/96khz files.4. The QB-9 has the option of going into standby after not receiving any data for one minute, as opposed to going into standby when the computer is off. This is a really neat feature as the my Alix is usually powered on (3w idle 4 watts playing FLAC) and neither the QB-9 or Alix has a power switch. In comparison, I had to manually unplug the Brick when I was done listening; its power supply has no switch, and the Brick's tube circuit only goes into standby when the computer is off or in standby. The Alix boards have no ACPI support, so no sleep or hibernate.I'm very impressed by the functionality so far. Getting an upgrade from Ayre to play 24/192 material in the near future is just icing on the cake. MPD currently supports 32bit/384khz audio, so no "gotchas" on the player side of things.OK, so now off to do some more "listening". I hope you enjoyed the update.Sincerely,Nick L.
Hi Nick,I was reading on the Vortexbox forum today that ALSA actually resamples the 44.1 files to 48:"You need to be aware that ALSA by default will upsample all of your audio to 48 kHz. This keeps it compatible with TV broadcasts as well as Dolby Digital and DTS surround on DVDs. ALSA typically takes the sound from your content, routes it through a module called "plug" where this resampling takes place, and then routes it to a module called "dmix", a software mixer, before it outputs it to your SPDIF/iec958 connector."Does this sound correct to you or any of the other Linux users out there? I am looking for an inexpensive low power solution (similar to the NMT I am currently using but I need to get it back into the HT) and I want to utilize USB out so I can try the Tranquility DAC. For me resampling the signal would take MPD and ALSA out of contention. I know that the NMT uses a hardware solution and does not require ALSA, however I do not know the validity of the quoted statement above.
By default, yes. With the Alix and MPD we specify that the stream should not be touched by ALSA in any way:audio_output { type "alsa" name "My ALSA Device" device "hw:1,0" # optional# format "44100:16:2" # optional# mixer_device "default" # optional# mixer_control "PCM" # optional# mixer_index "0" # optional}I had the same concerns when initially experimenting with MPD, ALSA, and Alix. Using the above configuration, I did confirm that MPD/ASLA would feed HDCD material to my Adcom GDA-700 DAC and the little HCDC LED would illuminate in agreement. if I didn't use the above configuration, dmix would resample to 48khz which I confirmed with the HDCD LED _not_ illuminating *and* seeing the sample rate in /proc/asound as 48khz.
Thanks for the response Nick and good job on finding a work around . Sorry for the additional question but did you have to add additional programming to enable your system to utlilize higher bit rates or did this script take care of the resampling issue across the board? One more thing, if I decided to utilize one of the embedded atom boards instead of the alix does that change any of the programming? IOW, was any of the programming alix specific?
First, it's not a workaround, per se. It's Linux and ALSA being open and configurable. Example being, you can use a laptop with an external USB DAC and configure it without dmix touching the stream, i.e., "bit-perfect", and keep the laptop's internal sound card at its 48khz sample rate using dmix.Secondly, no additional programming, i.e., code. This is all just *configuration* of MPD. And nothing special required for the Alix in regards to the higher sample rates as long as your DAC can handle what you're sending it. If not, e.g., sending 24/176 material to a 24/96 DAC, it will be down-sampled on the fly.Note: There is one small caveat in regards to MPD and DACs that support 24/96 or greater. Versions of MPD 0.15 and prior do not support 24 bit packed samples (S24_3LE), which is the native format of all 24bit DACs. With the newest mpd 0.16 theres is native support for S24_3LE. What does this mean if you use MPD 0.15 with 24bit DAC? If I remember correctly, some zeros get padded on. That is *not* the same as re-sampling, so no change in sound quality. Also, you have to use "plughw:0,0" in mpd.conf instead of "hw:0,0".There is a Voyage Linux .deb package of mpd 0.16~alpha in the experimental repositories (so no need to compile) made graciously available from the lead developer of Voyage Linux at my request. I have been using it for a while (with "hw:0,0" in mpd .conf) without any issues on the QB-9.
Ed,Does the NMT support NFS, or can it be added? I added NFS support to a D-Link D323 NAS using the Fonz Fun Pack, and so far so good. Still haven't had time toget thewhole thing operational, but that's only because I'm taking advantage of warm weather to get woodworking and painting work done on several amps and a pair of speakers.I'm also getting debian installed on my main work computer and getting a speech-enabled console app working so I don't have to SSH into the machine.Great fun!-- Jim
Thanks again Nick. I fear my Linux newbiness is showing .You have my gears turning now. I think this would fit in very nicely with my overall setup. As mentioned earlier I have a NMT that is running MPD, I will be moving it down to the HT. The NMT can also act as a server, it has a HDD with my FLAC files on it, they would both be connect to the router via ethernet so no wireless issues. I realize you are not familiar with the NMT platform but do you see any reason I couldn't let the NMT act as the server for the Alix? The NMT draws little power similar to the Alix, I am thinking I could run these both as always on units and still draw less power than a single standard desktop solution.You mention a new Voyage package with MPD included (?), is this available as an ISO? edit, I just reread your post and see that it is in alpha.I will dig into this further, I appreciate you sharing your work with us.
Well, I am going to try and join the club. Total newbie. I ordered the board and enclosure. I have a linear power supply somewhere from parts express that I will use with it. Want to avoid switchers. Have a buddy who likes to tinker with computers and is interested in linux so this will be good project. Wish me luck.Going to compare it to a mac mini setup. Feeding a Tranqulity DAC.-Tony
question(s?)For the music server machine, does that HAVE to run linux to work with the alix machine?(I am very new to this subject, so please be gentle) But poking around, seemed like there was a Samba program, that might work between a windows to linux machine, for transferring files over the network. I have an "extra" mac mini and a quiet little asus atom windows pc, either of which I could use for the music player side. But I could reformat/partition one for linux if necessary...TIA for help!-Tony