Hi!
I was doing basic reserches to build an Ethernet internet radio with Arduino.
But I can't find informations about the max audio bitrate you can stream with a similar configuration.
IMHO under 128kbps the quality is terrible 
, do you think it's possible to reach such speed?
Thank you 
An internet radio receiver with a normal Arduino board ? No, that's impossble.
The Arduino Due is faster (with a ARM processor), but the Ethernet will still be slow with a Ethernet module with the W5100 or W5200 chip.
The Arduino Yun has a module with linux inside. That module has wifi and ethernet, but it doesn't have a good way to make audio (I think, I'm not sure, I don't have a Yun yet).
You can use the Raspberry Pi. There are a number of example projects for internet radio. I don't know about the audio quality of the Raspberry Pi.
Maybe I could hook up one of those usb to audio stiks. Like here: http://dev.mikamai.com/post/69775973742/arduino-yun-with-sound-the-supereasy-way
But the quality remains unknown. A Raspberry maybe it's more indicated for a project like that
An internet radio receiver with a normal Arduino board ? No, that's impossble.
The below might be worth a look.