Computeraudio Primer for Linux with MPD

[The Computer Audiophile]

" have a custom version of Vortexbox with 500GB running in my 34 Ford with my Lynx L22 card as output."

 

Hi Jesus - Did I read that correctly? You have a 1934 ford with a Vortextbox and Lynx? That is the coolest thing I've heard in a long time!!! Photos?

 

[stakhanov]

IMO the most important thing for an audiophile : bitperfect or not bitperfect.

 

As far as I know Linux uses a mixer just like Windows. And if this mixer is used to play a musical file, there is always resampling quality loss.

Because of this some players bypass the mixer on Windows (Kernel Streaming)

 

But is it possible on Linux ? That's the question.......

 

[Guest]

You might be ill informed....Linux does not use a mixer and ALSA is bit perfect.

 

I can assure you that Linux is INDEED bit-perfect.

 

 

 

[stakhanov]

@ Dynobot

I'm really sorry, but I've read on many Linux forums that the mixer of all Linux distros is D-Mixer (in Windows it is K-Mixer......).

Both systems work with 48 KHz, so with a 44,1 KHz file there are always two resamplings, one from 44,1 to 48 before the mixer, and one from 48 to 44,1 after the mixer........and all this with quality loss due to mathematical inaccuracy.

 

Honestly I don't understand anything more........

 

 

 

 

 

[stakhanov]

.....and I've done some comparisons between a Windows based system with Foobar 2000 and Kernel Streaming, and a Linux based system with Aqualung and some other players.

Everytime my ears told me that the sound was a lot more accurate and clean on the Windows system.........

 

[vortecjr]

I'll come clean on the Ford! It's a 35, but my dad was born in 34 so what can I say lied to him and the story stuck...hahaha. It's dark now and raining so I'll drive it out tomorrow and take pics and post some links. It's got a 1996 Chevy Vortec fuel injected V8 engine with power everything:) AC, crusie control and power windows. All done by me except for the interior finish that was done by one of my good buddies. I grew up in a block that was the hot bed of car stuff in town and what can I say some of it rubbed off on me! One of my other good friends worked at Speaker Warehouse that was owned by the guys that own JL Audio and I was exposed to a bunch of car audio as well. As a result it also has a Sony tunner/cd player with aux input;) 5 channel Fosgate amp and JL Audio 8" sub in a stealth box.

 

I was having trouble coming up with a way to get the word out about Vortexbox and thought about using the car as a demo piece:) It's based on the 12V Intel Atom board you featured a few days ago with a Vortexbox OS, 500GB HDD, my trusty Lynx L22 audio card with analog output, Cardas analog cables and a wireless transmitter to broadcast to my iTouch for control of MPD. It does not rip (no drive) and does not really share (closed network), but it is really cool!

 

Jesus R

www.sonore.us

 

[agillis]

Aqualung is a GUI application. The xwindows GUI runs a mixer so that you can have a bunch of sound apps running at once. We are using mpd from command line with no GUI. MPD is talking to the hardware directly through ALSA.

 

You many want to repeat your test using a command line app that is talking directly to the sound card.

 

 

[vortecjr]

sorry for the delay! I don't know about the kernal streaming thing! However, I conducted the standard laymans test for bit perfect and played a a ripped HDCD from RR and my processor display confirmed HDCD playback. This may not be good enough for some, but I'm happy for this much at least. FYI MDP supports Pluseaudio. I took a look at the Nokia 770 and it appears to me that the screen is big enough for you to run the Vortexbox's GUI with SBS for MPD control. Pretty cool unit, but you need to connect to the same network Vortexbox is on to pick up the web GUI.

 

Jesus R

www.sonore.us

 

[igolem]

Very stable so far, nice work guys.

 

Still no joy on getting my Lynx AES16e recognized, which is unfortunate, and a show stopper for me.

Hats off to those who say they have it working, any help would be greatly appreciated.

 

agillis - have you looked at susstudio.org perchance? It may be an interesting way to package and distribute vortexvbox.

 

 

 

 

[vortecjr]

the base model is for on board outputs and usb output. If the MB has spdif then that as well. I understand you may have had some issue with Fedora in the past, but this is mostly a closed system and most people will not mess with the OS. Having said that, I have been pushing the envelope on mine (and I have a few) and they are rock solid and just work. Maybe the term AAC is wrong and I'm confused with mp4, m4p and m4a at the moment. I have to get back with you when I clear my head.

 

Jesus R

www.sonore.us

 

[vortecjr]

there is no support at the moment for the Lynx AES16e card. At least we looked around and did not find it! For whatever reason either the driver is different or the pcie is the issue. The only thing you can do is lobby the OSS guys. We can lobby them as well if it helps!

 

Jesus R

www.sonore.us

 

[The Computer Audiophile]

Too cool Jesus!

 

We may have to start another thread dedicated to this mobile music server and your sweet ride :~)

 

[igolem]

If the OSS guys would return email / phone calls it would be a good start. Mind it's only been a day

 

I dd contact Lynx today and they do offer and SDK so I think I may take this project on myself. In the meantime I will continue to lobby OSS (it seems likely they could get there the fastest) and if you can help lobby as well, please do so!

 

[steveww]

The V8 conversion thing is not needed this side of the pond as we have great access to all the Jag parts we need.

 

I would be happy to help out with any Linux issues you have.

 

[stakhanov]

Many thanks agillis ! Now I understand much more the way sound is treated in Linux ! I will have a try with mpd....

 

[vortecjr]

check out my post on Mobile Vortexbox Player (MVP) in my hot rod!

 

http://www.computeraudiophile.com/content/Mobile-Vortexbox-Player-MVP

 

Jesus R

www.sonore.us

 

[stakhanov]

No problem with the delay Jesus ! I live in switzerland, so most of the time when you are working I am sleeping and "vice versa".... ;-)

 

Many thanks for the answer !

If HDCD works, it means that it is bitperfect sound without a doubt. And I'm very happy to know that I will be able to use my Nokia as a remote.

 

Cheers !

 

[liorms]

@Jesus/AGILLIS

I own a Minerva FW DAC and would like to use FW as main interface.

I've already installed the Vortexbox distro on an old PC and it seems to be working perfectly with my SB3 connected optically to Minerva.

I'd like to take a step further and install a FW card on that PC and check if it works well with MPD player, what FW PCI card make/model should i use for this?

If all works well I'll build a completely silent box based on Chris's Origen based silent server AKA CAPS.

The important issue for me if what FW card could be used / supported by the vortexbox distro?

 

Thanks,

 

Lior./

 

[agillis]

Any card supported by ALSA will work.

http://www.alsa-project.org/main/index.php/Matrix:Main

 

 

[Guest]

Furthermore Firewire is ONLY supported by FFADO see link http://www.ffado.org/

 

http://ardour.org/system_requirements/audio_compatibility

 

Also if you want to use FW with Linux or a PC you want to use a card that has a Texas Instruments chip. Sometimes Via chips work but most always TI chips will work on a PC. Reason being only TI does NOT throttle their chips through put based on CPU load. Other chips will throttle the data which will lead to lots of stuttering and problems.

 

So far Weiss products are not supported and even they were you will have to build the driver, installing all dependencies etc. in typical Linux fashion.

 

I suggest you use a card that has spdif out and go that route...check the ALSA web site to make sure the card is supported and use the iecset command to configure the spdif out to optimal settings.

 

 

 

 

[Guest]

Presently FFADO does have working version of Firewire drivers. However as you may know, many people are not Linux savy enough to actually build the driver, trouble shoot and get it to work. Even though some products may not be "Officially" supported some have been know to work, when built by competent Linux people.

 

With the onslaught of so many Firewire DAC's Mac is corning the market on computer based audio because its the easiest and obvious choice. This plus computer audio is still under the radar of many manufacturers so companies like Microsoft and the Linux people have been slow to make Firewire support a priority.

 

I have asked the Linux Mint people to bring Firewire support to their distro's but unfortunately the voice of one does not carry far, not even the voice of a few. As a result I have asked everyone I know to partition Linux Mint to make it available. Until recently I have known of no other Linux distro as solid as Linux Mint. I have tried MANY disto's of Linux over the years. I have to say the Vortex is at the head of the class for Linux based computer audio. Like Linux Mint, everything works. You might consider looking into FFADO's code and implementing it for Firewire support.

 

 

 

[agillis]

Dynobot,

 

I consider myself a "competent Linux people" Tell me what packages you want and I make them standard in VortexBox. VortexBox is a distro designed for audio so anything that gives us better support for audio devices is top priority.

 

I sent you a PM with my email if you want to send me more information directly.

 

[Guest]

I sent you mail.

 

 

 

 

[vortecjr]

I added the Weiss units to the ffado list a few months back. Pieter at ffado is pretty cool and we made some good progress. We are pretty far along, but I'm willing to put up my Minerva to move the research forward and finish it off. I will be shipping my unit to Andrew to help out.

 

Jesus R

www.sonore.us

 

[liorms]

@Jesus,

 

From your signature I've noticed that you are already using the following:

Vortexbox->FW->Minerva ; Therefore I've assumed that there is a working FW card that is support under Vortexbox and will connect to Minerva. And I've asked what FW card are you using?

BTW - I've been working with Unix/Linux systems more than 10 years as system integrator/system for R&D companies ; so I do have "some" knowledge in that area & would like to contribute to this effort as BETA tester / other roles that might come handy here.

 

Lior./