Sound Card recommendation

[Khudsa]

Ohh patents... Well thank you.

[RealNC]

I'm not aware of one. This is proprietary stuff with lots of Dolby and DTS patents involved, and sound card vendors only support Windows. I don't believe the ALSA developers have access to the DSP documentation anyway, so they can't write DSP algorithms for Linux even if they wanted to.

So no, any expensive card with DSP hardware you buy is wasted with Linux.

Edit:
Unless you're an "audiophile" and want the high quality DACs for low SNR and stuff like that. For this purpose however, you should not buy a Xonar or other "desktop multimedia consumer" card. You should in this case look into stuff like the M-Audio Audiophile 2496 card. But IMO, this isn't worth it anyway. Sound quality differences are rather minimal and assume you're using very expensive speakers/headphones (and even then the differences in quality will be minimal.)

[Khudsa]

Thanks! Only Linux. You know other sound card with that extra dsp hardware functionality that works under Linux?

[RealNC]

I have a D1 (same as DX but for PCI instead of PCI express; I avoided the DX because it needs a floppy power cable to operate since PCI express can't deliver the same power as PCI). Driver support in Linux is nice. I bought it because of its low latency with ASIO (Windows) and JACK (Linux). If you don't intend to use music production software that requires low latency hardware, I recommend the Xonar DS instead, which only costs half the price of the D1/DX. Also, the extra DSP hardware functionality of the D1/DX (Dolby Digital/Pro logic, Dolby Headphone, etc.) is not available in Linux at all. If you also use Windows though, then go for the D1/DX. Gaming will be better with it (Dolby Headphone actually really works.)

[Khudsa]

A recommendation for a good affordable sound card that work for Linux?

I have searched and Asus Xonar DX seems good and supported by ALSA .

I don't understand very much about actual sound cards, brands etc.

It's not for professional use, is more for music (HI-FI stereo, headphones etc.) and some gaming.

Thanks.