If you knew the early ages of the PC, Turtle Beach must remember you something! It seems they are yet manufacturing high quality sound cards. Please apologize if I ever thought Turtle Beach was dead :p.
Why am I writing about this brand? I was not sure audio ports of my MacBook were S/PDIF ones. Now I know this is the case and I can directly connect the audio S/PDIF output of the MacBook to a amplifier. The doubt led me to seek a good USB sound card. Why USB? Because a MacBook has no PCMCIA (PC Card II nor ExpressCard) port. After a quick search I found the Turtle Beach Audio Advantage SRM and Amigo. There is a small comparative of the 3 USB sound card models produced by Turtle Beach. here is a review from overclockersclub.com.
Ok I can plug a S/PDIF cable between my MacBook and an amplifier. The problem is... I don't have an amplifier and don't plan to buy one soon. However, I want to listen to music with a decent quality on my laptop, and also to hear good audio when I watch a movie. That why I'm considering to buy a Turtle Beach AA SRM.Any feedback and experience are welcome! I hope it works fine with GNU/Linux and Mac OS X, Alsa natively supports it through snd-usb-audio module. I'd like to check that all features are supported because TT provides a proprietary win32 Control Panel and no linux tools :(.
Next step: find good headphones.