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ordered a new Linux PC for the holidays, now I have an extra PC for audio finally!

98.116.102.137
Posted on December 22, 2012 at 14:28:30
bullethead
 I ordered a Wild Dog Linux PC from system76.com for the holidays for myself. This replaces a rather modest Gateway PC which I had as my main desktop. The older machine is a slim gateway, dual core Intel, 4gb of ram, 1TB hard drive, running Ubuntu Linux 12.04. This should be good to hook up to my main audio system. I have a USB to SPDIF converter already, I am thinking of setting up MPD music player demon on it so I can control it with my tablet, and play FLAC files from my NAS. I noticed Cutthroat here had luck with squeezebox emulation, using something related to squeeze play with his Raspberry Pi, I can try that for mog.com support. He said it worked.

The machine will be headless meaning no monitor, does anyone know any drawbacks to such an idea? It does have a PSU, and a CPU fan, I don't think that will bother me too much however.

The new machine has 24gb ram, 1TB hard drive, quad core Intel i5 , so that will be my new desktop/squeezebox server/NAS.

I might get crazy with a real time kernel, looks like the sky is the limit now.

 

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RE: ordered a new Linux PC for the holidays, now I have an extra PC for audio finally!, posted on December 22, 2012 at 14:39:10
Dynobot
 Sounds good.

I was on the fence about building another audio computer myself....can't justify it though.

Have fun!

 

your web site will come in handy, posted on December 22, 2012 at 14:51:56
bullethead
 Dynobots Audio will come in handy for me, the mpd section is great.

Are there any good real time distros out there? I read somewhere that everything has to be re-compiled for real-time support to get the best performance out of all programs when using a real time kernel.

I would hate to have to go through a custom Gentoo install or something similar, I know Ubuntu Studio used to be pretty good, not sure if they support real time and have everything optimized for that now like they used to a few years ago. I remember reading they had to stop supporting linux-rt, but that was a few years ago.

Time to read up then on what's out there in terms of pre-packaged audio distros.

 

RE: your web site will come in handy, posted on December 22, 2012 at 15:05:30
Dynobot
Time to read up then on what's out there in terms of pre-packaged audio distros.
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Thanks for the comment about my website.

But, due to recent events its out of date. This pre-packaged audio distro kicks-ass.

I have been working with them to get some of my tweaks incorporated into the distro. If fact it was because of that distro that I was considering building another computer.



 

thanks, posted on December 22, 2012 at 15:11:09
bullethead
 I will look into it. I also record music and have been following Reaper multi track. Someone made an optimized is for recording and mastering called Remix. I will fiddle with that too.

I appreciate it,

 

RE: ordered a new Linux PC for the holidays, now I have an extra PC for audio finally!, posted on December 24, 2012 at 00:51:07
bassbinotoko
Audiophile

Posts: 469
Location: Vancouver Island
Joined: January 27, 2009
 If the graphics card has TV out or HDMI out, maybe you can hook it to a nearby TV if you need to see it boot or something. Alternatively, I've seen used LCD monitors as cheap as $5 (!!!) at yard sales, or less than $100 could get you a small LCD TV. Or with a little more effort, and assuming the graphics card has composite video output, attach a small LCD monitor salvaged from a minivan DVD player or the like.

Or... use an alphanumeric LCD like Matrix Orbital, Crystalfontz, a DIY one attached to the parallel port (but you probably ain't got one of those), or DIY USB one (see bit-tech.net). Or (best option?) buy one from eBay: search for USB LCD Smartie; they start at $23 shipped. There's the LCDProc driver for Linux/BSD; see the link below.

 

RE: your web site will come in handy, posted on December 24, 2012 at 05:25:22
aljordan
Audiophile

Posts: 1252
Location: Southern Maine
Joined: November 4, 2003
 I've been using Ububtu Studio 64 over the past few months with good results. It has a real time kernel and supports my firewire DAC with no special configuration. Also, the X-Server is a lot lighter than that which ships with the standard Ubuntu release. I know JACK supports real time kernel, but I'm not sure that ALSA does anything special with it.

I also have to give a nod to MPDPup if you want an easy to configure music server that sounds really good. You can run it off of a USB stick so you can keep whatever other operating systems you already have on your hard drive.

Alan

 

RE: your web site will come in handy, posted on December 24, 2012 at 10:07:44
jrling
Audiophile

Posts: 82
Location: London
Joined: September 16, 2011
 I second Dynobot too. mpdPup is great for Linux audiophiles. The Administrator ('Idolese')has worked really hard to make mpdPup as easy to install and configure for Linux Newbies like myself with intuitive wizards, but also to allow enthusiasts (like me!) to tweak MPD to increase sound quality of ALSA. As Dynobot says, you can run it booting off USB stick (or CF SATA) as the whole OS is just over 60MB in total, and I have Win 7 on the SSD to revert to whenever I want, completely untouched by mpdPup. No need for high power PCs to run it. I run mine headless and mpdPup comes with SSH built in, using say Putty for remote access.

SQ is definitely way ahead of say Win 7 (Optimised) with JRiver WASAPI Asynchronous.

 

RE: your web site will come in handy, posted on December 24, 2012 at 10:42:00
Dynobot
 Try WinSCP for SSH'ing into your Pup. It comes with built in Putty so you can run command line actions too. Other wise just click, click to what ever file you want to change, double click to edit and save.

  • http://winscp.net/eng/index.php

     

    • I'm going to check it out, posted on December 25, 2012 at 11:19:26
    bullethead
    		 next weekend when I have the time I will check out mpdPup,

    I think Linux has the best SQ IMHO, and much more potential down the line.

    thanks

     

    RE: your web site will come in handy, posted on December 26, 2012 at 06:19:00
    SBGK
    Audiophile

    Posts: 444
    Joined: March 22, 2012
    		 Dynobot

    Thanks for recommending mpddup, I have it running from a 256 sd card on an i3 laptop via HDMI to a NAD M51. Sounding very, very good.

    I tried to implement your renice tweak, but could not get it to run. Does it get called from another script ? In the end I added the following lines to .etc/init.d/20.mpd file just before the mpd line

    renice -10 3
    renice -10 9
    renice -10 13
    renice -10 16
    and uncommented the nice -n 15 mpd line

    Am impressed by how natural it sounds, a bit of a revelation compared to every other player I have tried.


    http://mqnplayer.blogspot.co.uk/

     

    RE: your web site will come in handy, posted on December 26, 2012 at 07:35:29
    Dynobot
    		 Hi

    I used WinSCP and placed a script inside the /root/my-applications/bin directory called [anything you want].sh

    #!/bin/bash
    renice -10 3
    renice -10 9
    renice -10 13
    renice -10 16

    P.S. Make sure you change permissions to the script. Also you can run command line commands by selecting the black-box directly under the "n" in the word Session. So try different renice commands etc from there. afterwards just type reboot to make your script file take effect.

    WinSCP Example:

     

    RE: your web site will come in handy, posted on December 26, 2012 at 07:54:49
    SBGK
    Audiophile

    Posts: 444
    Joined: March 22, 2012
    		 Thanks,

    created file in a console using vi and placed it in the my-applications/bin directory and applied +x permission. can execute from console, but on reboot the priorities are not set. At least I have a workaround.

    cheers
    http://mqnplayer.blogspot.co.uk/

     

    RE: your web site will come in handy, posted on December 26, 2012 at 12:29:48
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 Hi Dynobot and SBGK

    Firstly Dynobot - very many thanks for the recommendation of WinSCP, which is great.. Actually it has transformed my [mpdPup] life after struggling with the CLI and Putty. I will donate to WinSCP.

    Secondly SBGK - my experience with Dynobot's renice batch file was the exactly the same as yours. I am puzzled as one of the attributes of mpdPup is that one is logged in as root user by default and so executable rights should be automatic? I did however set x rights in WinSCP as user0 Root.

     

    RE: your web site will come in handy, posted on December 26, 2012 at 14:03:07
    Dynobot
    		 Hi jrling

    So were you able to get the writes to stick upon reboot?

    I hope Idolse is able to incorporate my other tweaks into MpdPup with the next release. Not that it needs it, because it already sounds great. But nothing wrong with being obsessive I guess.

     

    RE: mpdPup Tweaks, posted on December 26, 2012 at 14:37:28
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 Hi Dynobot
    No they did not stick on reboot. The same as SBGK. They work from CLI but are lost on reboot.
    Any help appreciated.

    Idolese has done a superb job on mpdPup. It is a labour of love of course and he has other priorities than obsessive tweakers (!) I am sure that he will get to your suggestions in due course. Idolese of course has to appeal to a wider audience and that's fair enough.

    I would really like to try out some (or all) of your suggested tweaks. The frustration is that mpdPup has deliberately not included many Linux utilities that are needed for your tweaks. I am a Linux newbie so am unable to take custom changes to the kernel without help. I suspect that if you wanted to lead the way with suggestions like your renice one above, many mpdPup followers would be very appreciative. I certainly am.

    My goal is to achieve as dedicated a music transport as possible with no frills and cut to absolutely only what is needed - one USB port only to stream out to my WaveIO S/PDIF Converter. Killing unnecessary processes (like Internet), shutting down to one USB port, priority setting, dedicated CPU core for MPD etc etc.

    So in summary - to follow in the hallowed footsteps of Dynobot! Well actually quite a few steps behind I am sure.

     

    Here Ya Go..., posted on December 26, 2012 at 15:14:32
    Dynobot
    		 Add the path to your script inside the rc.local file located in

    /root/.etc/rc.d/rc.local

    My path is /root/my-applications/bin/mpdstart.sh

    I made sure to open up permissions to the my-app..., bin, and the script with

    sudo chmod -R 755 my-applications

     

    RE: Here Ya Go..., posted on December 28, 2012 at 11:24:29
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 Followed your expanded help and the renice settings stuck with reboot. Many thanks. Will now audition for improvement.

    If only I knew how to add 'taskset' and 'chkconfig' in Busybox which Idolese uses, then I could have the full Dynobot monte!

     

    RE: Here Ya Go..., posted on December 30, 2012 at 07:43:32
    SBGK
    Audiophile

    Posts: 444
    Joined: March 22, 2012
    		 Here are some more settings to add into the mpdstart.sh file

    chmod 666 /sys/module/ehci_hcd/parameters/log2_irq_thresh
    echo 6 > /sys/module/ehci_hcd/parameters/log2_irq_thresh
    chmod 666 /sys/module/ehci_hcd/parameters/park
    echo 3 > /sys/module/ehci_hcd/parameters/park
    echo 999999999 > /sys/bus/usb/drivers/usbhid/module/parameters/mousepoll

    echo 1 > /proc/sys/vm/dirty_ratio
    echo 40 > /proc/sys/vm/dirty_background_ratio
    echo 5000 > /proc/sys/vm/dirty_writeback_centisecs
    echo 0 > /proc/sys/vm/swappiness
    echo 2048 > /proc/sys/kernel/msgmni
    echo 65535 > /proc/sys/kernel/msgmax
    echo 65535 > /proc/sys/kernel/msgmnb
    echo 40960 > /proc/sys/fs/file-max
    echo 50 > /proc/sys/vm/vfs_cache_pressure
    echo 0 > /proc/sys/net/ipv4/tcp_app_win
    echo "1000 1024000 512 2048" > /proc/sys/kernel/sem
    echo 268435456 > /proc/sys/kernel/shmmax

    http://mqnplayer.blogspot.co.uk/

     

    RE: Here Ya Go..., posted on December 30, 2012 at 08:06:31
    Dynobot
    		 Thank you for those.


    Doing a little research. Found that Oracle suggests

    SHMMAX= max value of shared memory segment = .5 * size of
    physical memory

    4Gigs should be 2147483648

    I will be applying the values in whole or part as I do some cross referencing.

    Thanks Again....BTW you might want to run these by the MPDPup forum.

     

    RE: Here Ya Go..., posted on December 30, 2012 at 08:21:17
    SBGK
    Audiophile

    Posts: 444
    Joined: March 22, 2012
    		 thanks for that

    the figure above for SHMMAX was for 256MB

    There is a change to the sound with these settings, to me it sounds less rough, but havn't done any testing to see which ones are most effective. Used them in the Touch ok.

    If you want to put them to the MPDPup forum then feel free. My feeling was that MPDPup was designed for a number of platforms which may restrict the number and type of tweaks of interest.


    http://mqnplayer.blogspot.co.uk/

     

    These Values????, posted on December 30, 2012 at 10:11:08
    Dynobot
    		 echo "1000 1024000 512 2048" > /proc/sys/kernel/sem
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~

    How did you obtain these values?

    The first value is SEMMSL and should be 10 plus the largest PROCESSES parameter [so first the largest process parameter needs to be obtained]

    The second value is actually obtained by multiplying the first with the last value. For example the current numbers in MPDPup are 250 32000 32 128. Therefore 250*128=32000



     

    RE: These Values????, posted on December 30, 2012 at 10:30:32
    SBGK
    Audiophile

    Posts: 444
    Joined: March 22, 2012
    		 I found these settings had an effect on the sound and I arrived at these by trial and error, there seems to be some effect on bass and treble depending on which values are used. So, yes, am aware of the recommended way of deriving the values, but these are ones arrived at empirically - think it is a matter of trial and error to find settings which you like.

    cheers
    http://mqnplayer.blogspot.co.uk/

     

    RE: These Values????, posted on December 30, 2012 at 10:33:16
    Dynobot
    		 Okay thanks


     

    RE: These Values????, posted on January 2, 2013 at 14:12:58
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 As suggested, I posted the suggestions for mpdPup tweaks to the mpdPup forum and the Administrator has replied -

    /proc/sys/vm/vfs_cache_pressure probably doesn't matter either as it sounds like it's also related to swap files.
    /sys/module/ehci_hcd/* - quite possibly relevant, more info would be good
    mousepoll - not sure if it's relevant when no mouse is attached, and not sure what it will do to X with that large a number defined when a user does want to use a mouse.
    /proc/sys/vm/dirty_* - not sure how relevant it is when the filesystem is always in memory, but it's possible that it would reduce 1's and 0's being shuffled around for no reason.
    /proc/sys/net/ipv4/tcp_app_win - setting this to zero seems to tell the kernel not to reserve memory for TCP activity - I'm not sure how this would be a good thing, so definitely need more background on this one, since TCP gets used heavily by anyone with a network share.
    /proc/sys/kernel/* - some of the suggested numbers seem quite large, definitely would want some background on the logic and what the impact on memory is along with audio, but I can imagine that changing some of these could have a positive impact. Most of these settings only show up in Google searches related to relational database tuning. I'm not saying they won't make a difference in MPD's performance, but a relational database and MPD are very different beasts.

    mpdPup runs 100% in RAM and so 'swappiness' settings and vfs_cache_pressure probably don't apply.

    He also asked - "lots of good stuff there to add to the wizard. I'd like to be able to document the purpose for each one, I'm not inclined to implement tweaks I can't explain."

    If SBGK could provide any explanatory documentation for why the changes help SQ or what they do (for me!), that would be most helpful.

    If SBGK wanted to do so, perhaps this discussion could move to the mpdPup forum thread here - http://murga-linux.com/puppy/viewtopic.php?p=674994#674994

    Thanks

     

    RE: These Values????, posted on January 2, 2013 at 14:58:32
    Dynobot
    		 Hi jrling,

    I looked into those settings SBGK posted. Perhaps some are on the right path BUT and a HUGE BUT...his numbers are extremely faulty. He got the numbers purely out of the air or out of his...well. Anyways I would not use any of them and even though some of the kernel tweaking can be done with proper numbers MPDPup is already at optimal. I spent some time and looked up the proper usage for each of those and how/why each value is used. I applied 'proper' values based on what Linux calls for, yes if you change the numbers the sound will change but each value is already at the optimal setting for Puppy Linux. I would caution plugging in random values like he does.

     

    RE: These Values????, posted on January 3, 2013 at 10:50:58
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 As suggested, I posted the suggestions for mpdPup tweaks to the mpdPup forum and the Administrator has replied -

    /proc/sys/vm/vfs_cache_pressure probably doesn't matter either as it sounds like it's also related to swap files.
    /sys/module/ehci_hcd/* - quite possibly relevant, more info would be good
    mousepoll - not sure if it's relevant when no mouse is attached, and not sure what it will do to X with that large a number defined when a user does want to use a mouse.
    /proc/sys/vm/dirty_* - not sure how relevant it is when the filesystem is always in memory, but it's possible that it would reduce 1's and 0's being shuffled around for no reason.
    /proc/sys/net/ipv4/tcp_app_win - setting this to zero seems to tell the kernel not to reserve memory for TCP activity - I'm not sure how this would be a good thing, so definitely need more background on this one, since TCP gets used heavily by anyone with a network share.
    /proc/sys/kernel/* - some of the suggested numbers seem quite large, definitely would want some background on the logic and what the impact on memory is along with audio, but I can imagine that changing some of these could have a positive impact. Most of these settings only show up in Google searches related to relational database tuning. I'm not saying they won't make a difference in MPD's performance, but a relational database and MPD are very different beasts.

    mpdPup runs 100% in RAM and so 'swappiness' settings and vfs_cache_pressure probably don't apply.

    He also asked - "lots of good stuff there to add to the wizard. I'd like to be able to document the purpose for each one, I'm not inclined to implement tweaks I can't explain."

    If SBGK could provide any explanatory documentation for why the changes help SQ or what they do (for me!), that would be most helpful.

    If SBGK wanted to do so, perhaps this discussion could move to the mpdPup forum thread here - http://murga-linux.com/puppy/viewtopic.php?p=674994#674994

    Thanks

     

    RE: These Values????, posted on January 3, 2013 at 10:55:32
    Dynobot
    		 Hi jrling,

    I looked into those settings SBGK posted. Perhaps some are on the right path BUT and a HUGE BUT...his numbers are extremely faulty. He got the numbers purely out of the air or out of his...well. Anyways I would not use any of them and even though some of the kernel tweaking can be done with proper numbers MPDPup is already at optimal. I spent some time and looked up the proper usage for each of those and how/why each value is used. I applied 'proper' values based on what Linux calls for, yes if you change the numbers the sound will change but each value is already at the optimal setting for Puppy Linux. I would caution plugging in random values like he does.


     

    RE: These Values????, posted on January 3, 2013 at 12:12:55
    SBGK
    Audiophile

    Posts: 444
    Joined: March 22, 2012
    		 A somewhat defensive reply Dynobot, anyone would think I had insulted your manhood. I don't see how the mpd settings are optimal considering it is set up to be a generic music player. No book is going to tell you what settings to use, considering most unix boxes are for database/client server applications and not many people listen to the sound of a database query.
    http://mqnplayer.blogspot.co.uk/

     

    RE: These Values????, posted on January 3, 2013 at 14:33:11
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 Hi SBGK

    I wondered if you would be up for what the mpdPup Administrator asked? "If SBGK could provide any explanatory documentation for why the changes help SQ or what they do (for me!), that would be most helpful."

    I am sure there is an interested audience hearing your experience with the settings. As I mentioned, probably better continuing the thread in the mpdPup forum thread here - http://murga-linux.com/puppy/viewtopic.php?p=674994#674994




    Thanks

     

    RE: These Values????, posted on January 11, 2013 at 14:08:25
    jrling
    Audiophile

    Posts: 82
    Location: London
    Joined: September 16, 2011
    		 Hi Dynobot

    I would be grateful for your clarification of what this SEM line should in your opinion read for mpdPup with a PC (like mine) with 4GB RAM?

    Many thanks

     

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