Linux Audio the way to go!?

[phofman]

Originally posted by erozsolt
Do you say that all 270x based chips resample internally, even for USB > I2S data, or only when used as a DAC?

There are a lot of DAC's around which use PCM2706/7 for USB > I2S which would mean, that all of them are lossy when used as USB?

The datasheet of PCM270x specifies it is the DAC which upsamples. SPDIF/I2S outputs are connected before the DAC.

[erozsolt]

OK, I start to understand.

The cheap way is to use common synchronous USB DACs and prepare the PC as far as we can. For example using Ubuntu Studio realtime kernel and disable every background daemon and use uncompressed wav and ramdrive. It's not quite comfortable, but practically it produces the lowest jitter a PC architecture can produce, and if for example using a dedicated moving part less mini-ITX box or Asus EEE PC with SSD, and start only a mpd on it, that could work like a Sqeezebox with USB port, using mpd network streaming. Do you know anything about if OS X could have as low jitter as a dedicated linux box could produce, or not at all?

The expensive way is to buy a high-end product from BD-Design or Wavelength, where they engineered a firmware and some custom solution for actually streaming the data from the PC to the DAC, and timing it with a high precisision clock. I prefer the BD-Design solution, because I don't know why, but all the "saying-to-be-bit-perfect" solutions on XP and Vista sound different. Why is there a difference between foobar's ASIO and J Media's ASIO? Why do I have 3 different settings on the high-end Vista player (I don't know the name, but it's the alternative approach to this topic) I don't want any settings for different sound on a transport!

So I beleive that if BD-Design sends redbook CD data to the DAC, it needs custom software, but that's the way of implementing things right. Not some 5 different sounding bit-perfect choice.

The wavelength's Windows part has the same limitations no matter what they do, when using the DAC as Windows' soundcard. Why do I have to set the volume at 50% and download different ASIO drivers and choose different ASIO players, when I bought a $7500 DAC. OK, it seems they concentrated on the mac part, and they prefer it over windows. Actually they prefer the G4 mac, as I found from the Brick's review.

[phofman]

Originally posted by erozsolt
OK, I start to understand.
....
The expensive way is to buy a high-end product from BD-Design or Wavelength, where they engineered a firmware and some custom solution for actually streaming the data from the PC to the DAC, and timing it with a high precisision clock. I prefer the BD-Design solution, because I don't know why, but all the "saying-to-be-bit-perfect" solutions on XP and Vista sound different. Why is there a difference between foobar's ASIO and J Media's ASIO? Why do I have 3 different settings on the high-end Vista player (I don't know the name, but it's the alternative approach to this topic) I don't want any settings for different sound on a transport!

......
The wavelength's Windows part has the same limitations no matter what they do, when using the DAC as Windows' soundcard. Why do I have to set the volume at 50% and download different ASIO drivers and choose different ASIO players, when I bought a $7500 DAC. OK, it seems they concentrated on the mac part, and they prefer it over windows. Actually they prefer the G4 mac, as I found from the Brick's review.

You never know what is happening in the Windows internals. Did you check the bit-perfection of each setup yourself? I kind of do not understand why people spend so much time analyzing the windows sound stack which changes for each windows version. If they want consistent top-quality and full control over their sound stack, they have complete source code of linux available.

If BD provides complicated drivers, then do not buy it I personally would not go for an expensive long-lasting device with proprietary drivers - will the manufacturer provide quality drivers for older models for the upcoming Windows 8?

Asynchronous USB (e.g. E-MU 0404) is technically "the way of implementing things right" too. I guess BD used the bulk mode so that they can utilize the bandwidth of USB 2.0 (and have e.g. an external USB drive hooked to the same USB line). The bandwidth of the old USB 1.0 has almost no spare capacity when running at higher sample rates and the sound card cannot share the port for proper performance (e.g. via a USB hub).

[soundcheck]

Hi folks.

Somebody mentioned earlier the Music Player Daemon as a nice alternative player.

I just tried it, because I was not really happy with Pulseaudio. (Background: I am in the process of setting up my home-audio/multimedia-network properly. I want to avoid the shortcomings of Squeezebox and similar devices.)

In fact MPD is a nice no-frill player alternative. And it sounds really good.

A very nice functionality is its client/server capability. This makes it possible to play your music from any place/client in the network and locally quiet easily.
You can even shutdown your remote client while playing back. The daemon keeps playing on the audio-machine.

I've chosen Minion a Firefox Add-On ( officially available in the Firefox Add-On database) as my prime MPD Front-End.

Just try it. Within 10 minutes you'll enjoy quite a nice setup. (Even my wife loves the easy handling!)

I put everything down which is required for a basic setup. Have a look over here:

http://www.diyaudio.com/wiki/index.p...icPlayerDaemon

Enjoy

[ackcheng]

Hi!

how is it compared to you BruteFIR player?

[soundcheck]

Originally posted by ackcheng
Hi!

how is it compared to you BruteFIR player?

I havn't tried it yet.
I still can't get Brutefir to work with the EMU 0404USB (my current desktop interface).

[soundcheck]

Hi folks.

I added a new Wiki for the ones interested to update their ALSA to the latest revision.

I think especially ALSA is worthwhile to keep up2date, which won't be the case if you
wait for distro updates. Without it my EMU 0404USB still wouldn't work.

It is a quick and dirty solution - phofman I hear you - but at least it works.
If all applications are gonna work 100% flawless - No idea.
Of course it is always better to recompile the applications based on the new libraries.
However usually it works without it.

http://www.diyaudio.com/wiki/index.p...AManualInstall

Drop me a mail if you want the file.

Cheers

[erozsolt]

I always wondered why not the other way around?

In my theory, a perfect system is a headless mpd server with no user interaction, just a config file to start playing back an icecast 44.1/16 WAV stream from a local computer, looking for the stream every 5 seconds. No input, no configuration, just an icecast stream over local network. I think a minimal linux for mpd and realtime kernel could be around 50 MB max.

On the client (stream server) side, everyone can do what he likes. For example use foobar or winamp or any fancy media player capable of icecast streaming. For foobar and winamp, there is Edcast DSP plugin.
http://www.oddsock.org/tools/edcast/

That way there is almost no processing and definately no HDD or CD seeking on the linux box. You can even terminate almost all other processes, since there is no need for X or any user interaction. Everyone can use what player he is used to.

[erozsolt]

A $50 NSLU2 could be the perfect high-end USB transport?
http://matrix108.wordpress.com/2007/...o-on-the-slug/

Same with an Asus 500g, running OpenWRT
http://www.equinoxefr.org/post/2008/...00gp-partie-2/

USB-audio on OpenWRT wiki:
http://wiki.openwrt.org/UsbAudioHowto

[erozsolt]

And finally:
NSLU2 Linux Wiki: Slug as Audio Player
http://www.nslu2-linux.org/wiki/HowTo/SlugAsAudioPlayer

Somewhere it says:

I tried the Linex FM transmitter and it works.
Recognized as USB-Audio - Burr-Brown Japan PCM2702