Soundcard for Linux

[Fat Randy]

I'm currently doing a lot of research because I intend to build me a Linux based audio pc. The basic setup will be very similar to the C.A.P.S. but I'm still not sure which soundcard to use. I've read many posts confirming good Linux support for RME products and of course I also checked the ALSA website which says the same.

 

Anyway I read some posts (among them the Voyage Linux - part of the C.A.P.S. post) writing about problems with automatic changing of the sample rate on the RME 9632, which is the card I like best so far. Since I assume this could be a very annoying fact I would like to know how things really look (is it true, is it false, what does it mean for every day use if it's true, etc). Therefore I'm asking every RME 9632 owner (or former owner) and Linux user (or former Linux user) to post their experiences.

 

[The Computer Audiophile]

Hi Fat Randy - I hope some readers chime in here with up to date information. Much of the RME Linux info I found was pretty old. I could not get the 9632 to change sample rates on the fly.

 

[matan]

 

Chris wrote:

I could not get the 9632 to change sample rates on the fly.

 

 

Under ALSA (on Linux), the RME cards don't switch sample rates on the fly. You can try to use external clock to change sample rates, but then again that isn't 'on the fly' either because your clock source must change over somehow.

 

IMHO, there is good reason for this - if there are any samples left in the card's buffer while the sample rate is changing, you might get some undesired output from the DAC. These cards are designed for professional use, where sample rate changes would be few and far between - and never on the fly.

 

[Fat Randy]

Thank you for your answers.

 

I guess this explanation sounds plausible. So how does it look like to change the sample rate? Is it kind of a complex process or is it just a few mouse-clicks / commands to get another sample rate?

 

[The Computer Audiophile]

Hi Randy - I used the RME card with Voyage Linux ( a Debian variant). There is no GUI. I setup scripts to change the sample rate. I could type a command like 44, 88, 176, or 192 to set the sample rate. Of course this required an ssh session to the server all the time.

 

[Fat Randy]

To be frank, my name is Dominik - Fat Randy is just my favorite user account name (title of a song I once liked, but the name stayed).

 

Well, I feared worse, this sounds useable to me. It's not exactly user friendly but it could be far worse. I guess I've come to a decision, as soon as I got the money I'll get me a RME 9632. Thanks so far, you were a great help!

 

[Miska]

I've been using Envy24-based cards for about ten years on Linux and these have been very well supported for a very long time.

 

Namely M-Audio Delta -series.

 

[Audio_ELF]

To be frank, my name is Dominik - Fat Randy is just my favorite user account name

 

Now I'm totally confused... Randall... Dominick... Now Frank?

 

Just a smiley... Eloise

 

[The Computer Audiophile]

Miska - Do you know if the M-Audio Delta series can play 24/176.4 files? This is a major drawback to many cards. They may be able to play 24/192, but few actually support 24/176.4. The RMA card does play 24/176.4.

 

[Miska]

Envy24HT support following rates, based on the driver source code:

8000, 9600, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000, 64000, 88200, 96000, 176400, 192000

And over S/PDIF:

32k, 44.1k, 48k, 88.2k, 96k, 176.4k, 192k

 

Older non-HT Envy24 support up to 96k (that is other than Audiophile 192 of M-Audio's "Delta-series").

 

[The Computer Audiophile]

Interesting. I know the the Audiophile 192 does not support 176.4.

 

[vortecjr]

what about the @Juli card for this application as it's in the same price range?

 

Jesus R

www.sonore.us

 

[Miska]

On Windows or on Linux?

 

M-Audio's Windows drivers are broken in general to say the least...

 

There is anyway bunch of other cards based on the same chipset.

 

(and according to M-Audio specs it does support)

 

[Miska]

At least the Envy24HT driver seems to have detection for Juli@ and Maya44. Thus should probably work... As well as Audiotrak Prodigy Hifi and Prodigy 192. Actually the Prodigy Hifi looks quite interesting.

 

[vortecjr]

I'm getting tangled up:) Is the support an alsa driver for linux that in turn supports the Envy24HT based chips and thus supports all the cards talked about or am I off base?

 

Thanks

 

Jesus R

www.sonore.us

 

[The Computer Audiophile]

The maya44 under Linux and alsa doesn't support 176.4 for sure. It's in the manual that I failed to read until I spent way too many hours trying to get it to work.

 

The Juli@ card does work great at all sample rates. The trouble can be finding the cards in stock.

 

[Miska]

Yes, there are practically two drivers, one for Envy24 and one for Envy24HT which cover most of the cards based on these chips.

 

Driver for AudioTrak (Prodigy) and ESI (Maya44/Juli@) card models is the same one. The only difference for the different cards in the driver is the code to set up the ADC/DAC chips.

 

From the Maya44 driver the specific code snippet:

static void set_rate(struct snd_ice1712 *ice, unsigned int rate)

{

struct snd_maya44 *chip = ice->spec;

unsigned int ratio, adc_ratio, val;

int i;

 

switch (rate) {

case 192000:

ratio = WM8776_CLOCK_RATIO_128FS;

break;

case 176400:

ratio = WM8776_CLOCK_RATIO_128FS;

break;

...

 

And:

/*

* supported sample rates (to override the default one)

*/

 

static unsigned int rates[] = {

32000, 44100, 48000, 64000, 88200, 96000, 176400, 192000

};

 

[Krisbee]

I have just joined this forum, so perhaps I'm a little late in offering my Linux soundcard experience. You didn't say if you were looking for a card to use with both analogue out or just digital, nor if you wanted up to 24bit/192kHz. If your audio PC is to be mini-itx in form then there's also the question of fitting a full size PCI card or finding a low profile card for the case of your choice.

 

I'd suggest three (inexpensive?) audio cards.

 

1. Esi juli@, an Envy24HT-S card which will work with all the rates you'll need up to 24bit/192Khz over digital out and analogue. Rates are auto detected in Linux using the ALSA snd-ice1724 module. If you only need digital out the card should work with the analogue part detached and a small mod to the back plate.

 

2. A member of the Xonar family. The Xonar DS is now reported as working bit-perfect at 44.1, 48, 88.2, 96, 176.4, and 192 khz with auto rate detection. This can be had in low profile format. See:

 

http://www.computeraudiophile.com/content/Bit-perfect-audio-Linux-882-and-1764-now-possible

 

3. A Chaintech AV710 (or clone). This a very cheap card that might be hard to find now and has been very popular with Windows and Linux users alike. It is another Envy24HT-S card and by loading the ALSA snd-ice1724 module with "option model=prodigy71" it's treated like the more expensive "Audiorak Prodigy 7.1" audio card. You get support for 44.1, 48, 88.2, 96, 176.4, and 192 khz sample frequencies, so no need to down sample hires files in Linux. But this audio card has a max of 24bit/96kHz over dgital out (toslink only). Both 176.4, and 192 kHz sample frequencies are down sampled in hardware.

 

I use 3 as the bulk of my audio file are in 16bit/44.1kHz FLAC/ape format and my Beresford TC-7520 DAC is limited a max resolution of to 24bit/96kHz. I mostly use the USB connection on my DAC and switch to the audio card for the few higher resolution files I listen to.

 

One small point, all Envy24 cards have to addressed as a "plughw" device in ALSA not "hw" as the hardware requires bitdepth padding from s24_le to s32_le format. I don't think this is determental to sq, but does increase cpu load slightly.

 

e.g.

 

[chris@home Downloads]$ mplayer -ao alsa:device=plughw=0.1 2L38_01_192kHz.flac

MPlayer UNKNOWN-4.4.1 © 2000-2010 MPlayer Team

Can't open joystick device /dev/input/js0: No such file or directory

Can't init input joystick

mplayer: could not connect to socket

mplayer: No such file or directory

Failed to open LIRC support. You will not be able to use your remote control.

 

Playing 2L38_01_192kHz.flac.

Audio only file format detected.

==========================================================================

Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders

AUDIO: 192000 Hz, 2 ch, s32le, 5111.4 kbit/41.60% (ratio: 638928->1536000)

Selected audio codec: [ffflac] afm: ffmpeg (FFmpeg FLAC audio)

==========================================================================

AO: [alsa] 192000Hz 2ch s32le (4 bytes per sample)

Video: no video

Starting playback...

A: 554.8 (09:14.7) of 554.0 (09:14.0) 5.1%

 

Exiting... (End of file)

 

 

[The Computer Audiophile]

Hi Chris - Thank you for the information and for joining the site :~)

 

[Fat Randy]

I'm going to use the card almost only for analogue output, because I don't have an external DAC. The price should stay under a maximum of 350€ and I aim to get the card with the best DAC for this price. Since I'm about to build a new PC, the size of the card doesn't matter at all, the PC will have to adapt to the audio card. The card should support up to 24bit/196kHz because I don't want it to fall short of my requirements for a long time.

 

Anyway thank you for your suggestions, any ideas how the DACs on these cards (and also the RME 9632) perform?

 

[The Computer Audiophile]

"The size of the card doesn't matter at all, the PC will have

to adapt to the audio card."

 

Said like only an audiophile can say it :~)

 

[Krisbee]

Of the audio cards mentioned in this thread, on paper, and by reputation the RME 9632 has the best analogue SQ. But the ESI Juli@ or Asus Xonar may not be far behind and whether the differences are clearly audible to you will depend on the rest of your kit and ears.

 

What is certain is that under Linux the ESI Juli@ or Asus Xonar will be more straightforward to use.

 

I've just re-read Chris Connaker's CAPS article and a couple of things struck me.

 

1. It wasn't immediately clear if the CAPS was spec'd to be both for analogue and digital out, or just digital out.

 

2. The ESI juli@ was never tested simply because of availability.

 

3. The RME9632 can be a struggle to work with under Linux.

 

4. The ASUS Xonar Essence ST was the audio card that he really wanted to recommend but fell back on the tired and tested and expensive Lynx card.

 

Hence I can only repeat my suggestion of using one of the ASUS Xonar cards now that they have bit-perfect drivers in ALSA 1.0.23 in Linux kernel => 2.6.34

 

See here: http://techgage.com/article/using_the_asus_xonar_essence_stx_under_linux

 

 

 

 

 

[Audio_ELF]

Does anyone know - do the ASUS PCIe cards work as well under Linux as the PCI ones?

 

How is the SPDIF output of the ASUS Xonar DX?

 

Eloise

 

[Krisbee]

Eloise,

 

The ALSA vendor matrix ( http://www.alsa-project.org/main/index.php/Matrix:Vendor-Asus) shows that the ASUS Xonar DX has been supported since ALSA 1.0.22 with Kernel => 2.6.27.35/2.6.31.1

 

But in practice this doesn't always mean that Linux support for the card is 100% as per Windows.

 

Google for it and you probably just find all those posts complaining about lack of support where made by early users of the card. Once support is there, few talk about it. If you read the techgage article you'll see that PCIe cards are supported and work well in recent Linux distros.

 

As to the SQ of the SPDIF, as I'm no electronics expert I can't say what difference, if any, there might be between say the SPDIF out of the more expensive Xonar cards and the DX. I don't know what sits between the AV100 chip and the shared digital out connection, or how the better dedicated connection of the more expensive Xonar cards might infulence SQ.

 

But I have no reason to think there would be any noticeable difference in the SPDIF out of the DS and DX cards under Linux.

 

The simple fact that a quality PCIe sound card, which is around £40-50 in the UK, works under Linux is great news.

 

 

 

 

 

[Krisbee]

Just to widen the choice further, one other audio card which has found favour here is the HT-Omega CLARO halo (http://www.htomega.com/clarohalo.html). It has some impressive specs on paper and has well reviewed and it is supported in Linux.