I am looking into getting a soundcard to do some cassette recording, and it seems a few places always have the external is better than internal for electrical noise. I have read a few people who have had problems when they have had internal sound cards with bad grounding getting powerline hum.

But is there any proof that modern USB or Firewire external sound cards have less noise than an internal soundcard?

Also if anyone would like to remmend a good card for recording, i would appriciate that. I am leaning towards the M Audio's Audiophile 2496 right now.

Thanks

I've heard good things about the 2496, though I've never used one.

I've had excellent results with the E-MU 0404. I've used it for transferring dozens of cassettes and DATs, as well as recording musical instruments - all with outstanding performance.
(It can also take advantage of Foobar's Kernel Streaming output function. )

24-bit/192kHz converters;
1/4" Analog In/Out (very handy for recording instruments!);
Optical S/PDIF In/Out;
Coaxial S/PDIF In/Out;
MIDI In/Out

$99

I have an Audigy 2 NX, the only problem is that when my laptop is operating in USB2 mode I can hear a high frequency bursts (avg 2 per second), fortunately the sound becomes inaudible as soon as the fans spin. Problem is corrected if I use USB1 mode, but with it I'm restricted to 48kHz @ 16 bits.

Is not a problem with the soundcard itself, it is the puter that's doing it. Just so you know.

Well, considering all the inherent noise in a regular tape cassette, I don't think there will be any difference in recording it with a $300 external device and a Sound Blaster Live Value

Theoretically external cards will have a cleaner signal by the virtue of the DAC not being anywhere close to your other computer components, but I've tried both good internal cards and good external cards (like the M-Aud. Firewire Solo) and they both had noise floors so low they were negligable. There are also such things as PCI sound cards with breakout boxes.