id rather take care of the preamps externally (less limiting). therefore, i only need one line-in that will give me a minimal noise floor. i'd like a headphone out, but that's usually standard. i'd like to keep it under $300.
Please don't use USB cards they are completely crap!
Use PCMCIA or nowadays better use a firewire hardware! Firewire is todays industry standard (Yamahas M-Lan is built upon for example) and most new notebooks have built in firewire.
USB is a slow serial protocol and is normally polled every 50 ms - way to much for pro audio.
If you're looking for really good converters with firewire, than take a look at Motu's homepage (Mark of the Unicorn )
A short thought: As mentioned a few tousand times: Buy cheap - buy twice!
Actually most PC laptops do NOT have firewire, they use USB. Mac laptops have firewire. Too bad, because as Struberg said firewire is much faster than USB. However if you are only recording 1 or 2 tracks ata time USB should be fine.
Howdy, before making a decision go check out the Roland/Edirol UA-5 (www.edirol.com). It has many of the same stats as the M-audio duo, but it is out now and has all the PC drivers (the M-audio is still working on the PC drivers for the Duo). The only time I have heard of the UA-5 and the M-audio Quattro go head to head, the UA-5 came out on top. I am not trying to knock the M-audio stuff, but I would take a peak at this before making a decision. If you look around on the net you can find the UA-5 for $266 shipped.