I've just got today the DAC E-MU 0204 USB and I can happily tell that it works on Linux (using the Arch Linux distro myself)
 
It was not automatic, though. I got the last alsa git repositories (kmirror and drivers) and had to recompile. If somebody is interested I will write a mini installation how-to.
 
Now listening to music using my new (and first!) DAC Rediscovering sound..... AMAZING
 
 

I'm also looking for some usb solution for linux.
Does the alsa driver automatically adjust sampling rate to the material being played ?
Are you able to play hi-res (i.e. 24bit/192kHz) files bit-perfect with E-MU 0204 ?

Would you please be so kind to post results of this command :

aplay -v -D plughw:0,0  some_hires_file.wav

(of course replace device name and filename with right values).

Thanks in advance.

Very unfortunately, my hard disk with Linux died last week. I got a mac and cannot try that command now. Furthermore, I'm surrounded by mac, windows, and solaris users, but not Linux ones... I may install Linux on my new mac and then I will try that.
 
I cannot confirm this, but I don't think it can sample at 192kHz, for even the official drivers for mac currently do not support that. Only for Windows so far.
 
As an inexperienced audiophile, I couldn't detect in any case any sampling problem. I played music both at 44.1 and 88.2 (supposedly supported)
 
 
I hope I could bring some help

Hi , Man!! Please write here  -  how you was runing your e-mu on linux  (now i'm setup Mint 13), step by step, if this not hard!