[ted_b]

Well, I have turned the corner on Alix sound quality.  Up until last night Alix always seemed to finish a distant second to my tweeked Macbook/Pure Music beta (integer mode).  These two transports are feeding via USB into the Antelope Zodiac Plus. 

I have alwsys felt that the digititis I hear with the Alix must be coming from the inexpensive power supplies I have tried to date, and when using a prototype BPT (thanks Chris) power supply the sound has cleared up quite a bit...I am sending the BPT back or would do more to comparisons..although the power supplies below are in quite different price categories (hint:  Chris's BPT is a steal   ).

So....cut to the chase....last nights setup has passed the tweaked Mac server and is my new reference transport, at least for now.    What happened?  Well some of you are aware that I have Paul Hynes' 18V (variable, but I've left it at 18V) hi-end power supply as the coordinator and starting point of the Hynes US mini-tour.  My goal was to hear how well it did powering the Antelope DAC, which it does very well.  However, so does Antelope's own Voltikus (their new outboard ps; David/Rydenfan bought a near new one on Audiogon and sent it to me for eval vs Hynes).  So although the Voltikus is dedicated to the Antelope DAC, Paul Hynes sent along a generic cable for use with other DACs...and it just so happens that it fits the Alix.  Well.......damn!   What a nice musical, tight, balanced, resolving combo!  Wow!   

Net/net, this minimalist approach works!  It just needs great power! 

[Alexdad54]

Ted_b,
Can you give the model of BPT you were using? I'd be interested in replacing the psu that came with my Alix board. The Voltikus is way out of my price league.....
cheers,
Dave

[praedet]

Ted_b,
I'd love to hear if you feel the Alix performs as well fed off it's own battery supply.  I have mine fed from a common one now, and it will be fed from a BatteryBUSS soon...

Ted

[ted_b]

Dave,
The BPT is a prototype but Chris is on AC.  PM him.  it's very good.

Ted,
I am not a battery fan, only because I am lazy and forgetful.    I even had to have Vinnie turn my battery ps (Squeezebox, years ago) into an AC one cuz of that.  I personally need no better Alix PS than the Hynes, believe me.

[praedet]

I am wondering if the Battery is as good as the Hynes supply, not the other way around

If I make a cord and a little supply that runs a few hours on AAs, would you be willing to compare?

Ted

[ted_b]

I'd love to, but my Alix's main squeeze (the Antelope Zodiac Plus) goes back to its owner tomorrow, as does the Voltikus.  I won't have a good Alix-capable DAC for awhile.    My next demo DAC is one of my faves from 2010, the Metric Halo LIO-8, but is not Alix-compatible (i.e not USB Class 2 driverless; it's firewire).

[nyc_paramedic]

I need some help folks.  Thanks to Nick's advocacy and the mutual support in this thread, I have decided to walk with the penguin. I haven't got the hardware yet as I wanted to convince myself I could cope with the software.  Right now I have questions about NFS.

This is my setup. I don't have the ALIX  yet, nor a file server/NAS, and decided to use my existing desktop PC as a software test bed by running  “Voyage MPD “ in Virtualbox .  But first I had to install Linux on my desktop and I choose PCLinuxOs as it seemed about as “plug and play” as you get in the Linux world with a full KDE4 desktop.  So PCLinuxOs acts as the file server and “Voyage MPD “ in Virtualbox mimics the “audio server”. 

I have a DAC with an adaptive USB input connected to my HiFi.  The audio and USB support of VirtualBox  means you can attach an USB DAC to “Voyage MPD “ as if you were plugging into a real machine.  Audio is in reality somehow piped from this virtual machine through your desktop. So it makes for a great testing/learning tool.

I've got to the stage where the Linux host can make a network connection  to “Voyage MPD “ running in Virtualbox, and vice versa, and I used “aplay” to test some audio files copied to Voayge.   

Taking the lead from the “cheap USB audio sever” blog,  I'm went with NFS before MPD but I'm stuck on trying to work out the correct file permissions to use. In fact, I think it's more than this as Linux has this concept of file/directory owner (user and group) in addition to read/write/execute permission.

This is my export (from PClinuxOS) :

   /home/fred/Music 192.168.0.55(rw,no_subtree_check,sync)

If I try and mount this on “Voyage MPD” I get an access denied message:

root@voyage:/# mount 192.168.0.10:/home/fred/Music /mnt/nfs
mount.nfs: access denied by server while mounting 192.168.0.10:/home/fred/Music

(User “fred” on the server has owner and group id of 501) . 

In reality, I think the shared music directory will be mounted as something like /MyMusic on the “file server”.  But I have no idea how its owner/group and permissions should be set, nor what those should be for the music files it contains.  What should I use?

This question may not be entirely divorced from the Voyage MPD configuration, as should I:

1. Add a user to  "Voyage MPD" that has the same user/group id as the user on the "file server" ?
e.g user "fred" on both, with both the same user and group id.  Debian seems to start at 1000 when you add new users.

2. Configure MPD to run as user "fred" on Voyage.

Add a user called "fred" on Voyage MPD, and configure mpd.conf with user "fred". But, I would wait until the Alix hardware comes in to set this all up. I don't know if your issue is related with having a virtual NFS setup.

[Eudyptes]

Nick, thanks for your input.

Clearly, I don't fully understand how NFS works re: permissions etc.  I solved my problem for now by changing the export to:

/MyMusic        192.168.0.55(rw,no_subtree_check,sync)

where /MYMusic is owned by user “fred” and now I can mount  the share in  “Voyage MPD” running in VirtualBox.  I never thought to check if my problem was a quirk of using a virtual machine. So I'm not sure why this export worked while the original did not.

Anyway, mpd is configured as you said and everything now seems to work.  I have mpd running in the “audio server” (Voyage MPD guest in Vbox) accessing the “file server” (PCLinuxOS host).  So far I 've used sonata and Firefox. Minion as mpd clients briefly to test audio files and listen to internet audio streams, like AVRO baroque.

I need to give some more thought to how to set up the share and mpd directories as I've just blindly followed the “cheap usb audio server” blog , so both music files and mpd files are in the same directory, I don't know if that's necessary or desirable. Surely you might want to have some general mount point on your sever for your music collection(s) which you can mount music on and then export as a NFS share, and would want to keep this separate for the mpd files held on the server. 

I'd be interested to know how others are doing this.

Obviously this not the real thing and there'll be other challenges to get “Voyage MPD” on the ALIX board etc.  But virutalbox has proved it's worth as a testbed and I glad I made the effort to get to grips with it.

PS I installed PCLinuxOs a few weeks ago as I was interested to know if Linux Audio sounded any better than Windows XP/Foobar/ASIO.  To my ears at least, and I couldn't really tell you how,  it did sound better.  Hence my interest in this project.

[Eudyptes]

I sorted out my previous error, it was a Linux beginners mistake.  My in “/home/fred/Music” path, the “fred” directory was not readable by “others”.  Simple when you know how.

My idea so far is to set the music_directory that mpd uses as a mount point on the audio_server to a local directory, export  the actual server music directory and use the fstab entry on the audio server to  map one to other, e.g

192.168.0.10:/home/fred/Music  /home/fred/Music  nfs   rw    0         0

This at least means changes on the server side would only need the fstab on the audio server to be edited , while the mpd.conf  remains the same. 

On the server side I'd like one fixed mount point that I could slot different sets of data into, my different music collections.  The only way I can think of doing this to (a) have stuff on different partitions, or (b) use what Linux calls symlinks.

With option (a)  you just mount what ever partition holds the music you want on your server, then update mpd to see it and select what you want.  The downside is reserving one or more partitions on your server for your one or music collections, e.g. music1, music2 etc.  If the data sets are relatively small and/or very numerous then many separate partitions is not practical.

With option (b) you make a link in a fixed mount point on your server to each music directory you want.  I discovered mpd folllows these links.  Unfortunately NFS doesn't follow these links. If you export something that contains links via NFS, the audio server tries to follow the link by looking for it in it's own directory structure, not the server's.  I believe SAMBA does follow links when fle sharing, but the setup is not straightforward.

Am I just over complicating things? I'd  like to know about other folks' ideas on a more flexible configuration of  directories on the server side and how to share them with the audio server.

[Eudyptes]

To  “plughw” or “hw” is a a question that's been asked a few times on this thread and I see that  praedet is/was using an MF V-link USB/SPDIF converter  as per  the mpd.conf  posted :
audio_output {
   type      "alsa"
   name      "Music Fidelity V-Link"
   device      "hw:0,0"   # optional
buffer_before_play      "100%"
filesystem_charset      "UTF-8"
id3v1_encoding         "UTF-8"
metadata_to_use "artist,album,title,track,name,genre,date,composer,performer, disc"

I just wondered how this worked. I've seen this elsewhere on the Internet:

cat /proc/asound/VLink/stream0
Musical Fidelity Musical Fidelity V-Link at usb-0000:00:02.0-1, full speed : USB Audio
 
Playback:
 Status: Running
   Interface = 1
   Altset = 1
   URBs = 3 [ 8 8 8 ]
   Packet Size = 582
   Momentary freq = 44100 Hz (0x2c.1998)
 Interface 1
   Altset 1
   Format: S24_3LE
   Channels: 2
   Endpoint: 1 OUT (ASYNC)
   Rates: 32000, 44100, 48000, 88200, 96000

So how does the V-Link handle 16bit/44Khz ?  If the V-Link is a 24bit device and you feed it a 16bit file wouldn't you need to use “plughw” in the mpd.conf?   If using plughw is no harm to SQ then to avoid having to keep editing the mpd.conf file, wouldn't it be easier just to leave it as “plughw” so you can play 16bit/44Khz  and any higher resolutions your USB DAC/converter can handle? 

Using “plughw” with ALSA doesn't necessarily involve any sample rate conversion, just padding out the bit format AFIAK.   This what I have to do with my cheap Envy24HT based soundcard if I use its optical out to feed my DAC.  Like a lot of  basic DACs, my USB input is limited to 16bit at 32, 44, or 48Khz so I use  "hw" to play 16bit/44Khz files via its USB input.

The one thing I learnt about Linux audio is how to use the "aplay" command to play an audio wav file , and so see if the audio hardware needs "plughw" or "hw" in ALSA.  If the hardware natively supports the file format you are trying to play in both bits and frequency then its "hw", otherwise its "plughw". Using "plughw" may mean only the bit pattern is padded out.

e.g.

aplay -v -D plughw:0,1 "01 - JazzDrumDynamics.wav"
Playing WAVE '01 - JazzDrumDynamics.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
Plug PCM: Linear conversion PCM (S32_LE)

[nyc_paramedic]

To  “plughw” or “hw” is a a question that's been asked a few times on this thread and I see that  praedet is/was using an MF V-link USB/SPDIF converter  as per  the mpd.conf  posted :
audio_output {
   type      "alsa"
   name      "Music Fidelity V-Link"
   device      "hw:0,0"   # optional
buffer_before_play      "100%"
filesystem_charset      "UTF-8"
id3v1_encoding         "UTF-8"
metadata_to_use "artist,album,title,track,name,genre,date,composer,performer, disc"

I just wondered how this worked. I've seen this elsewhere on the Internet:

cat /proc/asound/VLink/stream0
Musical Fidelity Musical Fidelity V-Link at usb-0000:00:02.0-1, full speed : USB Audio
 
Playback:
 Status: Running
   Interface = 1
   Altset = 1
   URBs = 3 [ 8 8 8 ]
   Packet Size = 582
   Momentary freq = 44100 Hz (0x2c.1998)
 Interface 1
   Altset 1
   Format: S24_3LE
   Channels: 2
   Endpoint: 1 OUT (ASYNC)
   Rates: 32000, 44100, 48000, 88200, 96000

So how does the V-Link handle 16bit/44Khz ?  If the V-Link is a 24bit device and you feed it a 16bit file wouldn't you need to use “plughw” in the mpd.conf?   If using plughw is no harm to SQ then to avoid having to keep editing the mpd.conf file, wouldn't it be easier just to leave it as “plughw” so you can play 16bit/44Khz  and any higher resolutions your USB DAC/converter can handle? 

Using “plughw” with ALSA doesn't necessarily involve any sample rate conversion, just padding out the bit format AFIAK.   This what I have to do with my cheap Envy24HT based soundcard if I use its optical out to feed my DAC.  Like a lot of  basic DACs, my USB input is limited to 16bit at 32, 44, or 48Khz so I use  "hw" to play 16bit/44Khz files via its USB input.

The one thing I learnt about Linux audio is how to use the "aplay" command to play an audio wav file , and so see if the audio hardware needs "plughw" or "hw" in ALSA.  If the hardware natively supports the file format you are trying to play in both bits and frequency then its "hw", otherwise its "plughw". Using "plughw" may mean only the bit pattern is padded out.

e.g.

aplay -v -D plughw:0,1 "01 - JazzDrumDynamics.wav"
Playing WAVE '01 - JazzDrumDynamics.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
Plug PCM: Linear conversion PCM (S32_LE)

First, no Voyage MPD user should be using buffer_before_play "100%". It is not what most think it is, i.e., buffering the entire file to RAM. On a local area network, i.e., audiophiles with Alix and NFS on a home LAN and not over the Internets, the default setting is just dandy.

Second, if the DAC supports 24/96 or greater then hw:x,y will work just fine with the Alix setup. There is no conversion needed as most 24/96 DAC will handle 16/44.1 just fine.

plughw was needed with version of mpd 0.15 and 24/96-192 DAC's.

[praedet]

So the buffer before play 100% is bad...

[nyc_paramedic]

So the buffer before play 100% is bad...

It can cause problems, yes.

[nyc_paramedic]

Well, I have turned the corner on Alix sound quality.  Up until last night Alix always seemed to finish a distant second to my tweeked Macbook/Pure Music beta (integer mode).  These two transports are feeding via USB into the Antelope Zodiac Plus. 

I have alwsys felt that the digititis I hear with the Alix must be coming from the inexpensive power supplies I have tried to date, and when using a prototype BPT (thanks Chris) power supply the sound has cleared up quite a bit...I am sending the BPT back or would do more to comparisons..although the power supplies below are in quite different price categories (hint:  Chris's BPT is a steal   ).

So....cut to the chase....last nights setup has passed the tweaked Mac server and is my new reference transport, at least for now.    What happened?  Well some of you are aware that I have Paul Hynes' 18V (variable, but I've left it at 18V) hi-end power supply as the coordinator and starting point of the Hynes US mini-tour.  My goal was to hear how well it did powering the Antelope DAC, which it does very well.  However, so does Antelope's own Voltikus (their new outboard ps; David/Rydenfan bought a near new one on Audiogon and sent it to me for eval vs Hynes).  So although the Voltikus is dedicated to the Antelope DAC, Paul Hynes sent along a generic cable for use with other DACs...and it just so happens that it fits the Alix.  Well.......damn!   What a nice musical, tight, balanced, resolving combo!  Wow!   

Net/net, this minimalist approach works!  It just needs great power! 

Ted,

Is this the Paul Hynes you're talking about? Link: http://www.paulhynesdesign.com/

I'm also looking for a decent power supply for my Alix. My 10 amp linear will be going back to ham radio duty.

[TomS]

Ted,

Is this the Paul Hynes you're talking about? Link: http://www.paulhynesdesign.com/

I'm also looking for a decent power supply for my Alix. My 10 amp linear will be going back to ham radio duty.

Nick,

That's the one. Paul offers a specialized regulator when it is intended to power a computer type of device. He has a circle here on AC as well and is very responsive if you shoot him an email.

I'm using the KECES supply and have been very happy for the dollars spent, though I'd definitely like to try the PH one at some point in the future.

Tom

[ted_b]

Right guy wrong ps.  Mine is called the SR3-18 (18V, variable down to 8V5).  I will shoot a couple pics before I send it on its next leg of the tour.

[nyc_paramedic]

Nick,

That's the one. Paul offers a specialized regulator when it is intended to power a computer type of device. He has a circle here on AC as well and is very responsive if you shoot him an email.

I'm using the KECES supply and have been very happy for the dollars spent, though I'd definitely like to try the PH one at some point in the future.

Ok, I posted. Let's see what he recommends and place an order.

[jrebman]

Does anybody know if and how one can use the second ethernet port as a pass-through?  I havve one ethernet jack in the bedroom and want to avoid getting a switch, but would like to run my alix hard-wired, and then plug the airport express into the second ethernet port on the alix so I can have both.

Thanks,

Jim

[jrebman]

Also want t know if the alix/mpd wll play ALAC files directly?

Nobody on the ethernet port config?

Thanks,

Jim

[nyc_paramedic]

Also want t know if the alix/mpd wll play ALAC files directly?

Nobody on the ethernet port config?

Appl lossless should work just fine.

As for your ethernet ports, I think you want bridging:

http://www.linux.com/archive/feature/133849?theme=print

http://wiki.debian.org/BridgeNetworkConnections

As always Google is your friend.