Linux Audio the way to go!?

[jkeny]

Hi Soundcheck,
You wondered how this would sound with a full digital amp like the SAXR57 that I'm tweaking on the other thread!

Well, I'm running the standard Wubi installation of Ubuntu & playing through a USB DAC kit (AWD3) which uses PCM2707 chip & it sounds very good - nearly as good as my best transport.

This is without a RT kernal or any tweaking of the OS (probably isn't feasible with Wubi?) SO there is a bit of improvement to be had yet I would imagine?

This is also without any tweaking of the USB DAC - self powred,etc. I would have liked to try I2S out from USB DAC feeding amp but I don't feel that this is possible - see my last post on other thread.

My sonic benchmark at the moment is HDMI (stereo from Oppo 980H) feeding the SAXR57 = stunningly real! Let's see if it can approach this level?

 

[ssmith]

Well, I'm running the standard Wubi installation of Ubuntu & playing through a USB DAC kit (AWD3) which uses PCM2707 chip & it sounds very good - nearly as good as my best transport.

This is without a RT kernal or any tweaking of the OS (probably isn't feasible with Wubi?) SO there is a bit of improvement to be had yet I would imagine?

With the same USB Dac input chip, I've also found standard a bog standard Ubuntu installation to be very good (and, for some reason, much better than Win XP no matter what XP tweaks I apply). I now dislike booting into Windows, even though the media player/organiser I use on it (J River Media Center) is far more user friendly than anything I've seen in Linux.

I've never tried the Wubi install, but imagine a clean and true install would be an improvement (I assume a Wubi install runs on top of Windows, no?). I also found the improvement from moving from a standard to an RT kernel to be very, very worthwhile, even without then getting into the more extreme tweaks Soundcheck and others here have suggested.

BTW Soundcheck, how's the new Ubuntu Studio 8.04 LTS wiki coming along?

 

[phofman]

Linux is no voodoo. Wubi does a very simple thing - it installs the linux partition into a file located on windows filesystem. It is no magic, linux can use the loopback device for mounting filesystems stored as files for many years.

It does not run on top of windows, only one more layer of filesystem driver is involved. It will hit disk performance a little bit. You can handle it basically as a regular ubuntu installation. However, it looks the ubuntu rt kernel does not like the NTFS/FAT filesystem driver as a loopback device http://ubuntu-utah.ubuntuforums.org/showthread.php?t=772539 I am having problems with other drivers on rt kernel too, it seems quite a few lines of kernel code are not ready for the pre-emption and raised HZ http://mailman.alsa-project.org/pipermail/alsa-devel/2008-May/007624.html

 

[maxlorenz]

Hi again,
Just an update of my own troubles...

Wifi problem: on "search" part of "Synaptic package administrator" I searched with "wifi" as search term and it allowed me to install "wifi-radar" and "linux-restricted-modules-rt", and problem solved

Audacious: tried various settings of buffers and always got nasty noises like lack of signal...maybe because I did not got the RAMDISK mod?

XMMS: XMMX did not play. Tried to install XMMS2 but failed
(now running Amarok)

RAMDISK: every try on the X-Term showed something like:
" "tmpfs /tmp tmpfs defaults,size=512m 0 0" >> /etc/fstab is not a valid directory " message It must be me that don't know how to tap well these instructions...Soundcheck, never thought about a holiday in Chile? We have fishing, skiing, extreme sports...etc

One out of four (1/4), not bad!

Cheers,
M

 

[TBM]

Hi Max

XMMS: did you use ctrl-P (preferences) and select 'output plugin' to ALSA, and 'configure' ALSA; select hw:1,0 (or whatever your dac has as id), not default. Under 'options' tab, tick off 'use realtime...' and then 'ok'. Press 'apply' and close preferences. Play you wav file...

Regarding RAM disk, just follow Soundchecks commands to the letter, like open terminal in root mode (sudo). It should work ok if you type it all correct (and don't miss important stuff like 'echo' )

Cheers,
Tom

 

[ackcheng]

Seems like a good distro

http://www.earos.dk/

 

[phofman]

Do I understand correctly they are charging 200EUR for the firewire driver to their HW? I am wondering how much of GPL code of other developers is in their driver.

http://www.acoustic-reality.com/news/headlines.htm

I could not find a detailed list of differences between the free and paid-for version.

 

[maxlorenz]

Hi Tom. Thanks and sorry for the very late reply: was out of town.

I will try your advices soon.
Cheers,
M

 

[fb]

What are the lowest latencies people are achieving for room convolution with brutefir?

I'm wanting to set up a small linux box to process incoming audio from spdif.

Ta

 

[breez]

I think 512 samples was possible with my dedicated P4 2.8GHz running 2ch convolution (65k taps) in BruteFIR. CPU usage was very high though and I don't need so low latency.

 

[SunRa]

Hello soundcheck,

when do you estimate an up-date on the wiki page? Will this contain any info about installing and setting brutefir player and brutefir crossovers? I would really like to take the next step with ubuntu-studio.

By the way, it happened several time that the sound from my computer to be really weird, very distorted (I had to low down the volume with 10% regardless of the player I've used). This happened while a friend was listening too and who has ubuntu studio at home after I've sent him this thread. Now, this weird behavior is not exactly rare and it happens quite often, but also it recovers without altering any settings (usually the next day or more ).

Now, would it be possible to experience this because of the quality of my mains? Is the only explanation I could come up with.

Thank you!

 

[phofman]

SunRa,

I really doubt quality of your mains would distort the sound in the way you describe. What sound card do you use, what are your PC specifications? Was there perhaps some hungry program running on the background (locatedb, the ubuntu file indexer, etc.) which perhaps overloaded the CPU?

 

[SunRa]

I really doubt quality of your mains would distort the sound in the way you describe. What sound card do you use, what are your PC specifications? Was there perhaps some hungry program running on the background (locatedb, the ubuntu file indexer, etc.) which perhaps overloaded the CPU?

Thanks for the reply phofman. I really doubt that it has to do with other backround processes. The CPU is 1Ghz Athlon with 256 Mb. The soundcar is an old 5.1 Creative. It is possible that I don't have enough resources for real time kernel. However that doesn;t explain why it does sound good most of the time.

 

[phofman]

SunRa,

right now I am running the RT kernel on Duron 1GHz, 512MB RAM. It is rather slow, but my Prodigy 192 can play internet radio streams with no hiccups even when compiling alsa drivers, my hobby

I remember reading something about problems with volume setup in the alsa audigy driver - too much volume made the sound distorted. Is this perhaps the direction to look at? Accidental change in the volume slider producing distorted output? You can check/compare the exact volume using the amixer utility.

 

[SunRa]

Hello,

I must admit I didn't experienced hiccups, even when running some other programs in the background. It happened though audacious to freez after just one track. In fact it hapened repeatetly. I didn't had the same problem with amarok.

But a problem never comes alone. I've installed yesterday a new HDD to pile up my cd's with EAC. And I did the mistake to partition in with the winXP install CD. When I reboot it the grub loader was not anymore and winXP loaded directly. I should mention that the win and ubuntu studio partitions are on the old HDD.

Now, can you please tell me if I can reinstall grub and recover my ubuntu install with the ubuntu live cd? My knoweldge is rather basic in linux and I tend to do it more straightforward (format -> install).

However my dvd is broken and i can only install ubuntu, as the Ubuntu Studio distro in bigger.


Thank you!

 

[UnixMan]

Hello,

But a problem never comes alone. I've installed yesterday a new HDD to pile up my cd's with EAC. And I did the mistake to partition in with the winXP install CD. When I reboot it the grub loader was not anymore and winXP loaded

well, I would say that this question would be more appropriate on a Linux support forum (such as http://ubuntuforums.org ) rather than here.

Anyway. There may have been two problems here.

First of all, you should make sure that the BIOS will keep booting from your old disk and not the new one. By default the BIOS usually tries to boot off the "first" HDD, which may be either the primary device device on the first IDE channel (PATA disks) or the first channel of the first SATA controller. Never BIOSes usually allow you to choose which disk to boot from without the need to phisically swap the disks.

Second, windoze installers (purposely? ) does not care about any other previously installed system and/or boot loader and overwrites the MBR (and/or boot sector) with its own default bootloader.

So what do u need to do? 1st of all make sure your BIOS tries to boot from your actual system disk.

I don't remember whether Ubuntu default install media provides a "recovery" mode (most distributions install media do). If it does, one of the most common things that these "recovery systems" provides is an automatic boot loader (e.g. Grub or Lilo) reinstallation. If it's there, just use it and you (should) be done.

Otherwise, boot off just about any live CD or DVD (e.g. an Ubuntu "live install" one, Knoppix, etc).

If the media you're booting from is for a system with a Kernel sufficiently similar to the installed one, you may pass a parameter to the kernel to directly boot your installed system, e.g.:

inux root=/dev/hda1

(from the boot prompt of the CD/DVD boot loader, assuming linux is the name of the kernel image and your Linux root file system is on the 1st partition on your primary master PATA HDD drive).

This will actually boot your installed system off the kernel on the boot media.

Otherwise, let the media boot normally, then open up a shell (terminal) and make sure you're root (use su or sudu as required). Manually mount your root partition, "chroot" into it then mount /proc, /sys and any other required file system (e.g., if your /boot or /usr f.s. are on separate partitions, mount them too). For example:

mount /dev/hda1 /mnt 
chroot /mnt
mount -t proc proc /proc
mount -t sysfs sysfs /sys
mount -av

Either way, once you are at a root shell prompt on your installed system (either directly or via a chroot), you may start the grub CLI interface and re-install it on the MBR:

grub

This will start the GRUB CLI which will allow you to reinstall the grub boot loader in the MBR.

Notice that Grub uses a different device naming scheme than Linux, and that device numbering is 0-based. That is, your 1st HDD is (hd0), and the first partition on it is (hd0,0). Thus, /dev/hda1 (or /dev/sda1 if SATA is 1st) on Linux will be (hd0,0) for Grub.

You may verify your current mapping by looking at the content of the file "/boot/grup/device.map", e.g.:

cat /boot/grup/device.map

which will list something like:

(hd0)   /dev/hda
(hd1)   /dev/sda

Back to the point, from the Grub CLI you'll have to give commands like:

help
help root
help setup
root (hd0,0)
setup (hd0)
quit

That's it. If there have been no errors, grub menu should appear at next boot.

Thus now you can unmount any f.s. you've manually mounted, i.e. if you have used the chroot method do something like:

sync
umount -av

and reboot...

Good Luck.

 

[SunRa]

UnixMan,

thank you for your reply. I'll try to keep with your advices. And you are right, it is not apropiate to post in this thread, just that hoped for a fast solution.

I think that the MBR could be overwrited, even if I hadn't installed windoze. I've just used the install CD to partition the new HDD (which by the way is slaved). The partitons with the installed OS (Linux and Win) where untouched.

Anyway, let's get back with audio. Do you know if Ubuntu 8.04 also comes with the option to install the real time kernel, just as ubuntu studio does? I think I could hapily return to ubuntu if it's not too hard to install the rt kernel.

 

[phofman]

SunRa,

please read a few of the latest pages in this discussion. We have already talked about the relationship between ubuntu and ubuntu-studio. The point is, you can freely switch between regular ubuntu and ubuntu-studio, as both are just a few packages away. All the packages (incl. RT kernel) are in the ubuntu repository.

 

[SunRa]

Ok, thanks, I usually read the new posts in this thread, maybe it just slipped away this time.

 

[ackcheng]

BruteFir Volume Control

Hi, I have just completed my setup with remote volume control for BruteFIR via CLI

In Lircrc, you need to add these code

begin
prog = iMON-PAD
button = Vol+
prog = irexec
repeat = 0
config = /usr/Volplus
end

begin
prog = iMON-PAD
button = Vol-
prog = irexec
repeat = 0
config = /usr/Volmin
end

For Volplus

v=`grep [0123456789] /Vol.txt`
tmp=`expr $v - 1`

if [ $tmp -lt 0]; then
tmp="0"
fi

lcd "Volume = -$tmp dB"
echo “cfoa 0 0 $tmp;cfoa 1 1 $tmp” | nc localhost 3000 > /dev/null
echo $tmp > /Vol.txt


For Volmin

v=`grep [0123456789] /Vol.txt`
tmp=`expr $v + 1`

if [ $tmp -lt 0]; then
tmp="0"
fi

lcd "Volume = -$tmp dB"
echo “cfoa 0 0 $tmp;cfoa 1 1 $tmp” | nc localhost 3000 > /dev/null
echo $tmp > /Vol.txt