Hardware for making AC3 without lack of quality?

[Killstun]

Can I make an AC3 file without any lack of quality, when I dont have a 5.1 soundcard installed, or will some of the information be discard? (I still want to keep all the channels)

[DJ Bobo]

If I'm not wrong, you have a DVD with 5.1 sound und you wanna recompress it right?
First, you've got the highest possible quality when you keep it as is.
Second, if you wanna recompress it to *any* other bitrate, you'll loose quality definitely: the lower the bitrate, the higher the quality loss.
So you undestand, that recompressing it to 640kbps will lead to a minimal quality loss, recompressing it to 256kbps will lead to a very high quality loss.

And one more point: the quality loss is there, whatever you do, whatever software or hardware solution you use.