I would like to buy a USB sound card compatible for Raspberry Pi. The main goal is to acquire sound from an external device and send it for signal elaboration on the Raspberry Pi.
What usb sound card do you suggest me to buy?
I've been using the Roland UA-1G for years, which is very high quality, but is discontinued. For the last two years, I have been using it with the Raspberry Pi without great problems. Just make sure that ALSA doesn't produce delay warnings, but there's a workaround for that.
Roland has a couple of new devices, of which I guess the UA11-mk2 could be quite affordable and of high quality. Make sure to set the EXT switch to the ** setting, or ALSA will not recognize the module.
As a matter of fact, any card would work with the Raspberry Pi. However, I have been using this external audio card for audio recording and playback with my Raspberry Pi for quite a while now. Have a look, http://goo.gl/P4mNRn